Chemical Smell

Chemical Smell
Identifying a certain smell is a complicated process, which is often unappreciated. Our sense of
smell is called olfaction. 7,000 people got surveyed and half of them said they would much rather
lose their sense of smell than not having access to electronics. "5 percent of our DNA is devoted to
olfaction, a fact that emphasizes how important our sense of smell is. "Smell begins at the back of
the nose, where millions of sensory neurons lie in a strip of tissue called the olfactory epithelium."
At the tips of these cells, there are proteins called receptors that hold odor molecules. The receptors
are like locks, and the odor molecules that float by are like the keys. People have 450 different types
of olfactory receptors, but dogs have two times ... Show more content on Helpwriting.net ...
Studies have shown that if you have brain damage, it is known to have affected the ability to smell.
The sense of taste creates an awareness of whether or not something put in the mouth is safe to eat.
There are five basic tastes, salty, sweet, sour, bitter, and umami. Umami is a savory taste of a
chemical called glutamate. It is found in foods such as bacon, corn, mushrooms, tomatoes, etc. "The
taste organ is a collection of specialized cells called taste buds." There are about 10,000 taste buds
on the tongue(top), and more in the throat, soft palate, soft tissue found at the back of the roof of the
mouth, and the epiglottis, the flap of cartilage at the bottombase of tongue. On the top and sides of
your tongue, there small bumps called lingual papillae. Three out of 4 types contain taste buds. On
the sides, there are the foliate papillae, which appear as a series of ridges. The small, rounded
projections found all over the tongue, especially at the and top of sides, are the fungiform papillae.
Each of these contain only 5 taste buds. "There are only 5–12 of the largest papillae, called the
circumvallate papillae, but they contain more than 250 taste buds
... Get more on HelpWriting.net ...

100 Mla Case Study
1. (odors were puffed over the antenna from a 100 ml syringe, and I used the same PowerLab
system and cables we used) except I used a different species of ant. The antenna got 10 alternate
stimulus presentations, 5 each of a plant volatile odorant (octanal) and 5 of blank air (in a sequence
of octanal, blank air, octanal. etc.). The figure demonstrates a difference in EAG signal after octanal
vs. blank air presentations. What explains this difference? Why is there any signal at all after the
blank air puff? In insects, the olfactory receptor neurons are located on the appendages, specifically,
the antennae. In the presence of an ordant, the receptor proteins bind with the specific chemical and
participate in a conformational change which

Comparison Of Receptors And Olfactory
Odors are a distinctive smell, especially an un unpleasant one. Odors attach to receptors of olfactory
cells in the nasal mucosa. Olfactory cells in the nasal mucosa are where they activate nerve signals.
These signals are processed in the olfactory bulb, a structure at the base of the forebrain that
transmit the signal to other brain areas. People have about 450 olfactory receptors. Each receptor
can be activated by many different odor molecules, and each odor molecule can activate several
different types of receptors. However, the forces that bind receptors and odor molecules can greatly
differ in strength, so that some interactions are better "fits" than others. The complication of
receptors and their synergy with odor molecules are what

Rabies Virus Analysis
The rabies virus attacks nervous tissue and appears to duplicate almost exclusively in neuronal cells.
As soon as delivered through the pores and skin or mucous membrane, the virus starts replicating in
the striated muscles on the wound part. The virus can reflect in muscle cells for hours or weeks, or it
could migrate immediately to the nervous system through unmyelinated sensory nerve endings on
the inoculation website online.
Migration to the nervous system is through the nearest sensory or motor neuron in the ganglion at
the base of the spinal cord or to the spinal twine itself. Once there, the virus continues to replicate.
(it can then be transported back to the wound part or as much as the brain through central nervous
system.)

Components Of The Olfactory System
The Olfactory System
Introduction
The human body is a complex organism that is composed of many different sensory systems. These
systems work together to create various sensations within the body. The olfactory system, also
known as the sense of smell, is one of the most imperative of all the sensory system. Mammals, both
humans and animals, depend greatly on the olfactory system whether it is cognizant or
unintentional. Many people fail to realize how much the sense of smell binds to almost every other
sense within the body. Many animals depend on the sense of smell as their primary sense. Humans
however depend on their vision as their primary sense but that doesn't mean humans are not
dependent of the olfactory system. To get an overall understanding of the olfactory system, it is
important to understand how it operates and travels within the body. Each function is vital to the
overall production of the sense of smell. It is also important to understand the connection between
the olfactory sense and the brain. Damage to any part of the olfactory system can have a big impact
on how you perform in your everyday life. A damage as minimal as a congestion can affect your
sense of smell that then transfers to the depletion of your taste. In more extreme cases damage can
result in disorders such as depression and Alzheimer s disease.
The Components of The Olfactory System Unlike many of the other senses, olfaction is a chemical
based sense. The olfaction system job is to

Sixth Sense: The Vomeronasal Organ Essay
Sixth Sense: The Vomeronasal Organ
"We are all more influenced by smell than we know." (Hercule Poirot)
....Murder in Retrospect, Agatha Christie
Biologists have long realized that the noses of most vertebrates actually contain two sensory
channels. The first is the familiar olfactory system, which humans possess. The second channel is
the vomeronasal complex, a system that has its own separate organs, nerves, and connecting
structures in the brain. The function of the vomeronasal system is the detection of pheromones,
chemical messengers that carry information between individuals of the same species. It was widely
believed (as I found in some of the older texts I examined) that humans had long ago discarded this
sensory system ... Show more content on Helpwriting.net ...
In a recent experiment, human VNO was reported to respond positively (by emitting electrical
signals) to puffs of air laden with substances claimed to be human pheromones (2). If the experiment
is valid, it presents strong evidence supporting the hypothesis that the human VNO is functioning,
not vestigial. In some respects, however, the proof is lacking. The human VNO lacks the
characteristic capsule and large blood vessels of other mammals' VNOs (2). The sensory epithelium,
as mentioned earlier, is not well developed. In addition, connections between the presumed VNO
receptor neurons and the brain have not yet been confirmed in humans. In other mammals, nerve
impulses from the sensory cells of the vomeronasal organ enter brain structures known as the
accessory olfactory bulbs and also project to brain structures that regulate sexual behavior and the
secretion of gonadotropin, a pituitary hormone regulating the function of the testes (4). The
accessory olfactory bulb, the normal termination of vomeronasal receptor–neuron axons (i.e. the
doorway to the brain for these signals), cannot be distinguished clearly in the human brain (2). But,
the structural inconsistencies (shortcomings?) of the human VNO system do not prove that it is
inactive. They merely indicate that it different, and perhaps less fundamental, than in our fellow
vertebrates, a notion that is readily apparent from more cursory observations. Recent

Major Motor Pathways Case Study
Look at Table 8.1 in which Carlson summarizes the Major Motor Pathways; consider the related
cortical and subcortical structures controlling movement. Then consider the relationship between
alpha motor neurons and extrafusal muscle fibers. Sir Charles Sherrington stated that the alpha
motor neuron (which is also referred to as the lower motor neuron) is the final common pathway. As
psychologists, this notion of the final common pathway being comprised of lower motor neuron
axons is very important to us. Considering the above information, why would Sherrington and
everyone since refer to the alpha motor neuron as the final common pathway? Incorporate
neuroanatomical information about motor systems to support your explanation. The alpha motor ...
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On top of the nasal cavity, lies the olfactory epithelium (mucous tissue that covers the cribriform
plate and contains the cilia necessary for olfactory receptors). The process starts when air enters the
nasal cavity and makes its way to the olfactory receptors. These olfactory receptors are located in
the olfactory epithelium and contain many bipolar neurons. These receptors send processes to the
epithelium where it divides into 10 to 20 cilia. Molecules of odor then must dissolve in the mucus
and stimulate the receptors in the cilia, which detect aromatic molecules. Next, each olfactory
receptor cell sends an axon into the olfactory bulb, which is located at the end of the olfactory tract.
Here, it forms synapse with dendrites of mitral cells (neurons of olfactory bulb), which takes place
in the dendritic and axonal aborizations, called the olfactory glomeruli. From there, the axons travel
to the rest of the brain, some terminating in the ipsilateral forebrain and contralateral olfactory bulb.
Furthermore, the axons of the olfactory tract project to either the amygdala, piriform cortex (region
of limbic cortex) and the entorhinal cortex (region of the limbic cortex). From the amygdala,
information then is sent to the hypothalamus. The entorhinal cortex sends its information to the
hippocampus. The piriform cortex takes its information to the hypothalamus and orbitofrontal cortex

Physioex 3 Essay
ACTIVITY 1: THE RESTING MEMBRANE POTENTIAL
1. Explain why increasing extracellular K+ reduces the net diffusion of K+ out the neuron through
the K+ leak channels?
When the diffusion is greater on one side, the other side will slow down.
2. Explain why increasing extracellular K+ causes the membrane potential to change to a less
negative value. How well did the results compare with your predictions?
There are two potassium's for every sodium so the increase of potassium will make it more negative.
Prediction was correct.
3. Explain why a change in extracellular Na+ did not alter the membrane potential in the resting
neuron?
The sodium channels are mostly closed during the resting state.
4. Discuss the relative ... Show more content on Helpwriting.net ...
Does the Pacinian corpuscle likely have this isoamyl acetate receptor protein? Does the free nerve
ending likely have this isoamylacetate receptor protein?
No
6. What type of sensory neuron would likely respond to the green light?
Physical sensory.
ACTIVITY 3: THE ACTION POTENTIAL: THRESHOLD
1. Define the term threshold as it applies to an action potential.
It is the transmembrane potential at which an action potential begins.
2. What change in membrane potential (depolarization or hyperpolarization) triggers an action
potential?
Depolarization
3. How did the action potential at R1 (or R2) change as you increased the stimulus voltage above the
threshold voltage? How well did the results compare with your prediction?
It did not change. Prediction incorrect.
4. An action potential is an "all–or–nothing" event. Explain what is meant by this phrase.
All stimuli that bring the membrane to threshold generate identical action potentials. The properties
of the action potential are independent of the relative strength of depolarizing stimuli.

5. What part of a neuron was investigated in this activity?
The Axon.
ACTIVITY 4: THE ACTION POTENTIAL: IMPORTANCE OF VOLTAGE–GATED NA+
CHANNELS
1. What does TTX do to voltage–gated Na+ channels?
It irreversibly blocks voltage gated sodium channel in the

Aromatherapy : How Real Is It?
Aromatherapy: How real is it? Many of us have read about Aromatherapy. Some of us have
experienced it. Aromatherapy has found its place within the spa environment, especially in a
massage room. If you are reading this article, chances are that you know what aromatherapy is
because of its undoubtedly popularity. Yet, the question continues to rise: Does it work? There are
still doubts of its effectiveness among the western medical population stating that research continue
to insist that there is no substantial evidence of its claims. Meanwhile, Herbalists and professionals
under the umbrella of natural medicine continue to embrace this modality and demonstrate its value.
What is Aromatherapy? It is important to first fully understand what aromatherapy is and how it
works before one can review the various scientific studies found about this popular modality.
Aromatherapy is the use of aromatic oils on the body predominantly by inhalation or massage.
These oils are extracted from plants (called essential oils). Dr. Jane Buckle, a critical care nurse
trained in Clinical Aromatherapy and well known as an educator in the subject, indicates that
essential oils have been used for therapeutic purposes for over 5,000 years. The ancient Chinese,
Indians, Egyptians, Greeks, and Romans used them in cosmetics, perfumes, and drugs. Egyptians
applied them after bathing and for embalming mummies. The Ancient Chinese compiled an
encyclopedia of information on the uses of plants,

Olfactory Synthesis
Olfaction, also known as sense of smell, is the detection and recognition of chemicals that contact
membranes inside the nose. Substances that we can smell in the air, or small airborne molecules, are
called odorants. Odorants bind to olfactory receptor proteins (G–protein–coupled receptors) in the
cilia of the olfactory sensory neuron to employ a second–messenger system to respond to the
presence of odorants. The sense of smell begins with receptor neurons in the nose. The olfactory
epithelium is responsible for detecting odors and has three types of cells: olfactory sensory neurons
(OSN), basal cells and supporting cells. Odorants depolarize olfactory receptor cells (or OSN)
through axons that travel through the cribriform plate–a bony barrier between the nose and brain.
The olfactory sensory neurons axons send ... Show more content on Helpwriting.net ...
Each glomerulus within the olfactory bulb is a tight little sphere of neural circuitry that receives
inputs exclusively from olfactory neurons that are expressing the same type of olfactory receptor.
Olfactory information is conveyed to the brain via the axons of mitral cells, which extend from the
glomeruli in the olfactory bulbs to various regions of the forebrain. Important targets for olfactory
inputs include the hypothalamus, the amygdala, and the prepyriform cortex (primary olfactory
cortex). The overall pattern of activity in the olfactory bulb and cortex determines the odor we
perceive. There are two types of olfaction: orthonasal and retronasal. Orthonasal olfaction involves
odorants being inhaled through the nose. Retronasal is the process in which humans smell through
the throat and nose. Odorants are forced up behind the palate, or expired, then diffused through the
nasopharynx to the olfactory receptors. This occurs when the odorants travel up the throat and into
the nasal cavity. It is important for food selection and therefore linked to

Sensory Processing Analysis
Themes of Sensory Processing Introduction Humans have five means of sensing information, which
are hearing, tasting, smelling, touching, and seeing (Breedlove & Watson, 2013). All incoming
information is sensed in a similar way for each of the five modalities. The sensory receptor organs
filter the information that we come into contact with by deciding which information to pay attention
to and which information to ignore. The event that activates the sensory organ is referred to as a
stimulus; hence, feeling a finger on your arm, hearing music, or seeing an object are all referred to
as stimuli. Additionally, we have receptor cells within or sensory organs, the receptor cells perceive
specific types of simulation and convert the sensed stimuli ... Show more content on Helpwriting.net
...
Throughout the research for this course I have come to believe that the auditory and olfactory
sensory processes are the most

What Are The Five Senses
All vertebrates possess five senses of sight, hearing, smell, taste and touch through which they can
experience and make sense of world. Without our senses, we wouldn't have any idea what was going
on around us and the human body would be functionally useless. Each of the senses therefore
provides important functions and serves an intended purpose. The sense of smell is a chemical
sense. It is called chemical sense as it detects the chemicals in the environment and it works on
larger distances. The sense of smell is a primal sense for humans as well as animals. From an
evolutionary standpoint, it is one of the most ancient of senses. Smell (or Olfaction) allows
vertebrates and other organisms with olfactory receptors to identify food, mates, predators, and
provides both sensual pleasure (the odor of flowers and perfume) as well as warnings of danger
(e.g., spoiled food, chemical dangers). For both humans and animals, it is one of the important
means by which our environment communicates with us (John & Leffingwell, 1994)
Smells are the perception of chemicals in the air or in our food. The ... Show more content on
Helpwriting.net ...
An odorant acts on more than one receptor, but does so to varying degrees. Similarly, a single
receptor interacts with more than one different odorant, though also to varying degrees. Therefore,
each odorant has its own pattern of activity, which is set up in the sensory neurons. This pattern of
activity is then sent to the olfactory bulb, where other neurons are activated to form a spatial map of
the odor. Neural activity created by this stimulation passes to the primary olfactory cortex at the
back of the underside, or orbital, part of the frontal lobe. Olfactory information then passes to
adjacent parts of the orbital cortex, where the combination of odor and taste information helps create
the perception of flavor. (Brain facts

Dosophila Larval Orn Experiment
The major conclusion from this study is that individual Drosophila larval ORN's are differentially
modulated by animal's starved state. We conclude this based on the following experimental
evidence: First, when we tested the olfactory responses of Drosophila larvae under starved
conditions, using the two–choice assay (Monte, Woodard et al. 1989), (Kreher, Mathew et al. 2008)
we observed changes in RI for only three out of the seven odorants tested. This experimental result
supports previous work from Mathew et al., 2013, which demonstrated functional diversity among
individual ORNs. Starved larvae had higher attractiveness to odorants acetal, pentyl acetate and 4, 5
dimethylthiazole. Each of these odorants elicit strong and ... Show more content on Helpwriting.net
...
We have observed that acetal, 2, 5 dimethylpyrazine had higher run speed and run length in case of
non–starved larvae while for pentyl acetate, the starved larvae had higher run speed and run length.
As of now we cannot explain the reason for this reversed trend in the case of pentyl acetate.
However, with the trends that we have observed for acetal and 2, 5 dimethylpyrazine we conclude
that not all ORN's show similar tracking effect under starvation. Each ORN is functionally diverse
and act as functionally non–equivalent units. From our results, overall, we conclude that ORNs
contribute differently to the olfactory circuit under changes in internal states such as starvation.
These results further support previous studies regarding existence of functional individuality among
neurons (Mathew, Martelli et al. 2013). Starved state of the animal impacts olfactory behavior via
GABA signaling As mentioned previously, local neurons secrete GABA and LN's are primarily
GABAergic interneurons (Ng, Roorda et al. 2002). Olfactory receptor neurons express GABA (B)
receptors (Root, Masuyama et al. 2008) and strikingly each ORN channel has unique baseline levels
of GABA (B) receptor expression in adult flies (Root et al., 2008). When the levels of GABA (B)
R1 in ORN::Or 42b and in ORN::Or 47a were decreased we observed no effect on starvation
dependent behavior

Olfactory Paper
LEHMAN COLLEGE
BIO 320: NEURAL DEVELOPMENT December 22nd, 2015
ABDUL BAIS AHMED
Problem: Role of Retinoic acid in central nervous development
Olfactory neurons are chemosensory neurons whose role is fulfilled by maintaining direct contact
with the outside environment, which sometimes expose them to harm. As a result, there is the need
to have a source of progenitor to replenish the damaged cells. It's widely known that olfactory
epithelium (OE) regenerates and replaces damaged olfactory neurons in the vertebrates' lifetime. OE
is derived from olfactory placode (OP) and is composed of olfactory receptor neurons (ORNs), non–
neural cells as well their progenitors. It is located in the non–neural ectoderm anterior tip of the
embryo. ORN ... Show more content on Helpwriting.net ...
However manipulations like mutation, knockout and overexpression of genes either re–affirm their
role or prove otherwise. I therefore recommend that such manipulations be utilized in future works
to throw more light on the different outcomes that relate to those manipulations with regards to the
OE progenitors
The understanding of the molecular mechanisms underpinning the functions of most signaling
molecules had been shrouded in complexity and RA is no exception. It takes detailed research work
to unravel these mysteries. This research paper did a yeoman's job by shedding more light on the
complex molecular mechanism involving the role of RA signal in the cell division and proliferation
of olfactory progenitors in the central nervous system. Balmer JE, Blomhoff R: Gene expression
regulation by retinoic acid. J Lipid Res 2002,

Essay On Starvation Based Modulation
Since we have established the working model for starvation based modulation we wanted to confirm
it using molecular techniques. Firstly, we wanted to check the levels of relative gene expression of a
few important genes between starved and non–starved larvae. We performed qRT–PCR analysis
with larval whole heads. We looked at relative expression levels of these genes: Orco, GAD1,
GABA (A) receptor, GABA (B) receptor R1, GABA (B) receptor R2 and GABA (B) receptor R3.
We haven't found any significant difference between starved and non–starved larvae for all the
genes above except Orco. The relative gene expression of Orco was significantly much higher in the
case of non–starved condition. Since qRT–PCR analysis was done for ... Show more content on
Helpwriting.net ...
We used Orco–Gal4 and 10x; UAS–CD8; GFP to drive GFP into the ORNs. We used primary
antibody that was a chicken anti–GFP (1:150, Invitrogen) and rabbit anti GABA (B) R1 (sequence
mentioned above) in 0.2%PPST+5% normal goat serum (Triton X–100). Samples were incubated
overnight at 4 degrees C. Secondary antibodies were a goat anti–chicken Alexa 488 (1:150,
Invitrogen) and a goat anti–rabbit Alexa 647 (1:75, Invitrogen) in 0.2% PBST+5% normal goat
serum. GFP staining was clearly observed in ORN's which is represented in Figure 10. This result
suggests that ORN's project much deeper into the brain than thought previously. Next, we looked for
the presence of GABA (B) receptors in the larval antennal lobe. Immunohistochemistry analysis
were performed in animals expressing GFP in all 21 ORNs. We found that GABA (B) receptor R1
localized to the ORN synaptic terminals. We conclude that the GABA (B) R1 is localized at the
ORN synapses. Root et al., 2008 observed GABA (B) receptors on ORNs in adult flies. Here with
our results, consistent with Root et al, we are seeing GABA (B) receptors staining in larval stage
too. Staining image is represented in Figure 11.
GABA (B) receptor is not found in the uniglomerular PN's Next, we looked at the uniglomerular
projection neurons for the presence of GABA (B) receptor R1. We don't know if uniglomerular PNs
have receptors for GABA (B) in the larval stage. To address this question, we used GH–146 gal4
that labels a

Dna Report : Neural Tissue Lab Report
Neural Tissue Lab Report
Introduction
Activity 1: The Resting Membrane Potential
Neurons respond to two different ions: potassium(Na+) and sodium(K+). There is usually a higher
concentration of Na+ ions outside the cell(extracellularly) which makes the cell more positive,
rather than inside the cell(intracellularly) where there is a higher concentration of K+ ions which
makes the cell more negative. This is explained as the resting membrane potential of a neuron;
where there is a potential deferens of ion concentration. In cells ions will move from a region of
higher concentration to a region of lower concentration and that is the concentration gradient. If
channels permeable to an ion, then it will allow it to diffuse to where the ion ... Show more content
on Helpwriting.net ...
An action potential is usually started at the initial junction of the axon hillock and with the initial
segment that region is called the trigger zone. It is important for a neuron to reach threshold so that
the chemical message can be propagated along an axon. If potassium is increased, then
depolarization would occur eventually leading to threshold and action potential. An ignition in the
action potential in the body normally follows a large depolarizing receptor potential. Activity 8:
Ca2+ Levels and Neurotransmitter Release
In order for an axon to send information, it has to release neurotransmitter stored in the synaptic
vesicles in the axon terminal. In order for this to occur, Ca2+ ions must first be present in the axon
terminal, and an action potential must have been initiated. This experiment will be researching if
Ca2+ levels in an extracellular solution will affect the amount of neurotransmitter released at an
axon terminal. Will a larger concentration of Ca2+ ions present in the extracellular fluid, induce a
greater release of neurotransmitter, and if there is no Ca2+ present in the solution, will no
neurotransmitter be released?
Materials & Methods
Activity 1
Materials:
Neuron
Extracellular solutions:
Control
High Potassium
Lower sodium

Microelectrode
Microelectrode manipulator controller
Oscilloscope
Method
First place the neuron onto the petri dish, then fill the

Notes On Nerve Impulses
PHYSIOEX 9.0 REVIEW SHEET EXERCISE 3 Neurophysiology of Nerve Impulses NAME :
_HIMA BHARATHA ________ LAB TIME/DATE: WEDNESDAY A.M. LAB______ ACTIVITY
1 The Resting Membrane Potential 1. Explain why increasing extracellular K+ reduces the net
diffusion of K+ out of the neuron through the K+ leak channels. ___The concentration of
extracellular K+ ions would be high and this would prevent more K+ ions from diffusing out of the
cell. 2. Explain why increasing extracellular K+ causes the membrane potential to change to a less
negative value. How well did the results compare with your prediction? ___ My prediction was that
the membrane potential will not change and that was wrong because the resting membrane potential
changed from –40V to 0V. This happened because K+ diffuse out across the membrane and they
leave a net negative charge behind. ___ ___ 3. Explain why a change in extracellular Na+ did not
alter the membrane potential in the resting neuron. ___ _There are less leakage channels for Na+
compared to K+_that's why it didn't alter the membrane potential in the resting neuron._ 4. Discuss
the relative permeability of the membrane to Na+ and K+ in a resting neuron. ___ _ The resting
neuron is 4 to 5 times more permeable to K+ then to Na+ because of the leakage channels._ ___ 5.
Discuss how a change in Na+ or K+ conductance would affect the resting membrane potential. ___
_There would be a greater change in the resting membrane potential in K+ than in Na+ because of
more K+

Physiological Perception Filters
"When a person glimpses the face of a famous actor, sniffs a favourite food or hears the voice of a
friend, recognition is instant. Within a fraction of a second after the eyes, nose, ears, tongue or skin
is stimulated, one knows the object is familiar and whether it is desirable or dangerous. How does
such recognition, which psychologists call preattentive perception, happen so accurately and
quickly, even when the stimuli are complex and the context in which they arise varies?
Much is known about the way the cerebral cortex, the outer rind of the brain, initially analyses
sensory messages. Yet investigations are only now beginning to suggest how the brain moves
beyond the mere extraction of features–how it combines sensory messages with ... Show more
content on Helpwriting.net ...
"PHASE PORTRAITS" made from electroencephalograms (EEGs)
generated by a computer model of the brain reflect the overall activity of
the olfactory system at rest (above) and during perception of a familiar
scent (right). Resemblance of the portraits to irregularly shaped, but still
structured, coils of wire reveals that brain activity in both conditions is
chaotic: complex but having some underlying order. The more circular
shape of the right–hand image, together with its greater segregation of
colour, indicates that olfactory EEGs are more ordered–more nearly
periodic–during perception than during rest.
Also, how does the brain achieve what is called generalization–over– equivalent receptors? Because
of turbulence in nasal airflow, only a few of the many receptors that are sensitive to an odorant are
excited during a sniff, and the selection varies unpredictably from one sniff to the next. How does
the brain recognize that signals from different collections of receptors all refer to the same stimulus?
Our investigations begin to suggest answers to both problems.
Many of our insights were derived from intensive studies of the olfactory bulb. Those experiments

show clearly that every neuron in the bulb participates in generating each olfactory perception. In
other words, the salient information about the stimulus is carried in some

The Neuroscience in Human Functions
In neuroscience there are many components that play important roles in the many human functions.
They are part of the reasons why human are complex and can perform complex actions. Categories
that show the importance of neuroscience is divisions and subdivisions of the human nervous
system, neurotransmitters & receptors, neuromuscular, vision, audition, somatosensory, olfaction,
gustatory, emotion, learning and memory, and communication.
The divisions and subdivisions of the human nervous system consist of the central nervous system
(CNS) and the peripheral nervous system (PNS). CNS consists of the brain and the spinal cord. In
the brain anatomy it consists of the frontal lobe, parietal lobe, temporal lobe occipital lobe,
cerebellum, and medulla oblongata. They all play in major components of the forebrain, midbrain,
and hindbrain. The forebrain consists of the telencephalon and diencephalon. In the telencephalon
consists of the cerebral cortex, basal ganglia, and limbic system. The diencephalon consists of the
thalamus and hypothalamus. The next component of the brain is the midbrain also known as the
mesencephalon. The mesencephalon is composed of the tectum and tegmentum. The last part of the
brain is the hindbrain, which consists of the metencephalon and myelencephalon. The
metencephalon consists of the cerebellum and the pons. The myelencephalon, consists of the
medulla oblongata. The next part of the CNS is the spinal cord. It is the CNS tissue that extends
caudally

The Vandenbergh Effect
Vandenbergh effect When a female miceis raised along with the malemice ,the pubertal development
of the female mice is increased .This phenomenon is known as Vandenbergh effect(57)(58);But
when a femaleis raised with a castrated malethe puberty is not accelerated(59).Removalof VNO in
the female mice eliminated the role of male urine in accelerating puberty.(60) Bruce effect Bruce
effect is the tendency in which the female mice terminates their pregnancies upon exposure to the
odors of unfamiliar male.Pregnancy is unaffected when the female mice is exposed to the mated
male.Thus females are able to respond to odour of familiar and unfamiliar mice.The first
vomeronasal stimuli identified that can induce Bruce effect are MHC peptides.(61)62) .Bruce effect
fig from zufall 2006 Lee–Boot Effect Lee Boot effect is a ... Show more content on Helpwriting.net
...
The MOB receives sensory input from the main olfactory receptors and project to the
lateralolfactory tract(NLOT),the anterior cortical nucleus(CAN),and the posteriolateral cortical
amygdaloid nucleus(PLCN) Neuronal Circuit controlling chemosensory cue with

bio flashcards
The areas of Michael's brain that were injured during his birth affected his control over his voluntary
movements. Which part of the nervous system distributes motor commands to skeletal muscles?
Somatic nervous system
The somatic nervous system controls the contractions of skeletal muscles and is under voluntary
control.
Which principle descending motor pathway provides conscious control over voluntary muscle
movements?
Corticospinal pathway
The corticospinal pathway is also called the pyramidal system and provides conscious motor control
over skeletal muscles.
Which principle descending motor pathway primarily controls muscle tone and balance? the
vestibulospinal tract of the medial pathway
The vestibulospinal tract provides ... Show more content on Helpwriting.net ...
it would lead to a quick sensation of pain it would lead to a slow sensation of cold it would lead to a
quick sensation of cold it would lead to a slow sensation of pain
Axons that decussate between the pyramids of the medulla oblongata belong to the ________ tracts.
reticulospinal anterior corticospinal vestibulospinal lateral corticospinal
Which of these are NOT part of the afferent division of the nervous system?
Cranial nerves I, II, and V
Dorsal roots
Ascending tracts of white matter
Ventral roots
The tract carrying sensations of pressure and pain is the __________.
Fasciculus cuneatus
Spinocerebellar tract
Posterior column tract
Lateral spinothalamic tract
The __________ tract carries information for maintaining balance.

Lateral coticospinal
Rubrospinal
Anterior corticospinal
Vestibulospinal
Which of these is not a property of chemoreceptors?
They trigger visceral reflexes
They are found in carotid bodies
They are interoceptors
They are classed as nociceptors
Identify the type of information that travels along the anterior corticospinal tracts
proprioception to the cerebral cortex pain and crude touch sensations visceral motor commands to
smooth muscle motor commands to skeletal muscles
A mechanoreceptor in the papillary layer of the dermis that responds to fine touch is a
Free nerve ending
Ruffini corpuscle
Root hair plexus
Tactile (meissner) sorpuscle

Nervous System Lab Report
The nervous system has two major part called central nervous (CNS) and Peripheral nervous system
(PNS). CNS contains brain and spinal cord, and PNS contains 12 pairs of cranial nerves and 31 pairs
of spinal nerves. Both nervous systems depend on each other. PNS further divided into somatic,
which supply impulses from brain and spinal cord to the skeletal muscle and autonomic nervous
system to the internal organs., which is further divided into sympathetic and parasympathetic
nervous system.
Brain control all the human system by sending a message through the spinal cord and PNS. Most of
the actions occurred in the brain. A neuron is the basic unit of the nervous system; it has two
extensions from cell body called dendrites and axons. Axon sends ... Show more content on
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It's responsible for the sense of smell. Receptors are located in the nasal cavity. Once airborne
particles enter the nasal cavity, they interact with neural receptors. For this test stimulant, should be
non–irritating. Start testing one nostril at a time and the close the other one. The patient needs to be
close their eyes during the test. To perform this test, you can use soap, perfume, etc. if patient able to
recognized the smell that indicates it's normal. But if patient not able to be recognized the smell of
the stimulant that indicates its damage to all factory nerve. If unilateral loss It could be brain lesion
affecting the olfactory bulb or blocked nasal passage. bilateral loss can occur with rhinitis.
XII Hypoglossal Nerve: This nerve is a motor to the tongue. For this test, you can use a tongue
depressor. In this test, physician observes the tongue atrophy or enlargement. It's difficult to relax
the tongue and then patient need to protrude the tongue and push it laterally against the tongue
depressor. After that patient need to move the tongue from side to side. if there is a facial weakness,
the tongue will appear to deviate. The tongue should be able to stick out straight. Minimal degrees
of deviation affecting only the tip are insignificant. If the tongue is weak, the tongue move towards
the weak

Catnip Research Paper
Catnip and catmints are mainly known for, the effects they have on cats, particularly domestic cats.
Approximately two thirds of cats are susceptible to the effects of catnip, as the phenomenon is
hereditary. The fact that it only elicits such a response in a proportion of cats–and that it is such a
dramatic response–suggests that a genetic element is involved that is enriched in domesticated
breeds. Catnip contains nepetalactone, a terpene. Cats detect it through their olfactory epithelium
and not through their vomeronasal organ. At the olfactory epithelium, the nepetalactone is
hypothesized to bind to one or more G–protein coupled receptors on the surface of sensory neurons
which are found in the sensory layer of the organ. Via a signal transduction

The Somatosensory System
Sensation is the input about the physical world that's obtained by the sensory receptors. There are 5
primary human senses: sight, smell, taste, and touch and each are perceived through our eyes, ears,
nose, hands, mouth, etc.
Sight is the ability for our eyes to focus and detect visible light on the preceptors in our eyes which
then create nerve impulses for features like color, brightness, and etc. There are 2 types of
photoreceptors; rods, which are responsible for our ability to see in dim light and cones, which are
responsible for our ability to see in bright light, image clarity, and more. The photoreceptors
transduce light into electrical signals that can be sent to the brain for further processing. Some
neuroanatomists consider the ability of each photoreceptor as type of sensation by itself.
Hearing is the sense of sound perception and ... Show more content on Helpwriting.net ...
Our sense of touch is controlled by a huge network of nerve endings and touch receptors in the skin
known as the somatosensory system. This system is responsible for all the sensations we feel.
Within the somatosensory system, there are four main types of receptors: mechanoreceptors, pain
receptors, thermoreceptors, and proprioceptors. Mechanoreceptors decipher sensations such as
pressure, vibrations, and texture. The thermoreceptors are responsible for perceiving the temperature
of objects we touch. Pain receptors do exactly as they are named, they are responsible for detecting
the feeling of pain. Finally, proprioceptors sense the position of the different parts of the body in
relation to each other and the surrounding environment. When your hand touches an object, the
mechanoreceptors in the skin are activated, and they start a chain of events by signaling to the
nearest neuron that they touched something until the message reaches the brain, and causes a
reaction (Pediaopolis

Role Of Neurological Change
The overall picture of neurological changes following early moderate PEE
1.1. The role of GABA signalling system in the developing brain
The embryonic brain development process commences after the neural tube is closed at neurulation.
Progenitor cells in the brain start to proliferate in the progenitor zone, where they transform into
postmitotic cells and migrate to different brain regions. Once they reach their final destination, they
start to grow their axons to make connections with other cells (synaptogenesis). When the axons
reach their correct targets, these connections are strengthened by myelination [255]. In rodents,
myelination continues until the first two postnatal months [255].
GABA signaling system plays a critical role in ... Show more content on Helpwriting.net ...
Ligand–gate ion channels are a family of neurotransmitter receptors, which include GABAa and
glutamate [228].
1.2. Multi–level abnormalities were detected in the brain following an early moderate PEE profile
Our study showed that moderate PEE from GD0–8 can produce significant brain abnormalities at a
gross level as well as at microscopic level. These abnormalities may be largely linked to the effects
of ethanol in early gestation, which was shown to induce disruption of the GABA signaling system,
including altered functions and expression of GABAa receptors. Brain alterations were observed in
adult animals, suggesting long–term persistent teratogenic effects of PEE on the CNS.
Gross volumetric changes included:
(1) a smaller third ventricle and a smaller left lateral ventricle;
(2) local shrinkage of the ventral olfactory bulbs, septal region, thalamus, motor, somatosensory,
auditory, visual and ectorhinal/entorhinal/piriform cortex, caudate putamen, hippocampus, PAG,
outer layers of lobules IV–V and pyramus (VIII) of the cerebellum;
(3) local enlargement of the olfactory tract areas, outermost layer of frontal pole, motor and visual
cortex, left anterior cingulate, right hippocampal commissure, bilateral dorso–caudal CA1 of the
hippocampus, inner layers of lobules IV–V of the cerebellum and ventral medullary reticular
nucleus.
Tissue microstructure changes included:
(1) reduced AD in the anterior cingulate region, motor and

Visual Cortex Function
The visual cortex is related to the primary visual cortex, labeled V1 and Brodmann area 17, and
extrastriate visual cortical areas V2–V5. [12] Located in the occipital lobe, V1 functions as the
primary relay station for visual input, transferring information to two main ways marks the dorsal
and ventral streams. The flow back covers V2 and V5 areas and is used for visual interpretation
"where" and "how." The ventral stream comprises areas V2 and V4, and is used in the interpretation
of "what." [13] Increases in Task negative activity in the ventral attention network are observed after
sudden changes in sensory input, [14] at the beginning and end block tasks [15] and at the end of the
completed study. [16] Auditory cortex Temporal lobe is ... Show more content on Helpwriting.net ...
The cortex like two main structures: the anterior insula, the island flap and the front cover in the
frontal lobe. Similar to the olfactory cortex of the way like working through both peripheral and
central mechanisms. Peripheral taste receptors on the tongue, soft palate, pharynx, esophagus, and
transmit the received signal to primary sensory axons, where the signal to the nucleus of the solitary
tract in the medulla, or the flavor of the nucleus of the solitary tract projected complex. The signal is
then transmitted to the thalamus, which in turn projects the signal in a plurality of areas of the
neocortex, including gustatory cortex

How Does Starvation Affect Larval Behavior
Starvation impacts larval behavior as measured in the two–choice assay a) 3rd instar larvae: From
previous studies of our lab (Newquist, Novenschi et al. 2016) we learnt that each larval ORN is
functionally diverse and each ORN differentially contributes to olfactory behavior in the Drosophila
melanogaster larvae. Based on these results, we postulated that individual ORNs might be
differentially modulated under starved state conditions. To begin to address this question we started
with a panel of seven different odorants from the panel of 19 different odorants published in the
study by (Mathew, Martelli et al. 2013). Each of the seven odorants elicits a strong, specific
physiological response from a single ORN (Or 47a :: ... Show more content on Helpwriting.net ...
Larvae on each half are counted, RI is calculated using simple equation RI =(S–C)/(S+C) [S denotes
number of larvae on the odorant/test side and C denotes number of larvae towards the control side].
The data from this experiment is presented in Figure 1. When tested for odorant acetal, starved
larvae showed higher RI when compared to non–starved larvae. In other words, starved larvae have
a stronger attractive response towards acetal compared to the non–starved larvae. Next, we looked at
the olfactory responses of the remaining six odorants from the panel of seven that were mentioned
above. As mentioned in the previous paragraph, starved and non–starved larvae were subjected to
the two–choice assay after 2 hours of the starvation protocol. Data collected for all seven different
odorants are shown in Figure 2. Of all the seven odorants tested, only three odorants showed
significant changes in response indices upon starvation. Acetal (shown in Figure 1), 4, 5–
dimethylthiazole, and pentyl acetate were the three odorants that showed higher RI values for
starved state larvae when compared to non–starved larvae. In other words, for these three odorants
starved larvae had higher attractiveness towards odorants compared to non–starved larvae. This
supported our hypothesis that individual ORNs might be differentially modulated by the animal's
starved state. b) 2nd instar larvae: Next, we looked at the olfactory behavior response of 2nd

Wachowiak Observation Report
On Tuesday, January 30th, Matt Wachowiak from Yale University gave a seminar on functional
imaging of the olfactory bulb in mice. He uses a fluorescent calcium–sensitive dye to label the
receptor neurons in the nose; the dye is then transported to the terminals of those neurons in the
olfactory bulb. All of the receptor neurons that express receptors for a certain type of odor molecule
send their axons to the same localized structure within the olfactory bulb, called a glomerulus. By
removing the skin and bone above the olfactory bulb, he can use a sensitive camera to record real–
time changes in fluorescence in particular glomeruli that correspond to activation of different
receptor neuron types in response to different odors. Dr. Wachowiak began these studies in turtles, ...
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Although an individual glomerulus may be activated by several odors, the relative levels of
activation of several glomeruli differ between odorants. As the concentration of the odorant
increases, more glomeruli are recruited to respond; however, the relative pattern of activation is
usually maintained for each odorant. Dr. Wachowiak also showed that there is a topographical map
in the olfactory bulb such that odorants belonging to a certain class of molecules tend to activate
glomeruli in the same area of the bulb, and this map is consistent across animals. Thus, it is possible
to study the response to many odor molecules in a large number of animals and collapse the data
across subjects to obtain more statistical power. In conclusion, this is an interesting technique that
can be used to understand the detailed mechanisms of first–order olfactory perception in live
animals. Dr. Wachowiak hopes to continue this research by conducting psychophysical experiments
to determine how well the mice discriminate between odors, using genetically encoded probes of
neural activity to selectively image certain populations of glomeruli, and studying further steps of
processing within the

Smell Disorders
Trailer "Stop and smell the roses" is a famous idiomatic reference many make when they want to
convey the importance of appreciating the beauty of life. But have any of us imagined what it may
be like to NOT smell the roses or anything for that matter? Humans often take their sense of smell
for granted, as they rely more heavily on sight and sound in day–to–day activities. Yet smell–in my
opinion– can be such an important aspect of life as the brain has the capability to associate smells
with danger and it can even elicit memories. For example, the odor of smoke notifies us that
something dangerous could be happening, or walking into a bakery with the smell of fresh chocolate
chip cookies can cause pleasure, bringing back childhood memories ... Show more content on
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"The most common causes include head injury (common in young adults) and viral infections or
Alzheimer disease in older adults" ("Loss of Smell–Ear,Nose, and Throat Disorders"). Head injuries
may result in anosmia due to "damage or destruction to the fibers of the olfactory nerves where they
pass through the roof of the nasal cavity. Sometimes injuries may also cause a fracture to the
cribriform plate" ("Loss of Smell–Ear,Nose, and Throat Disorders"). Infections and tumors near the
cribriform plate also can damage the olfactory nerve. Some less common causes of anosmia include
the overuse of antibiotics ,which may kill off all the olfactory neurons at once. If the cause is due to
sinus infections or irritation, doctors may suggest a treatment of steam inhalation, nasal sprays,
antibiotics, and occasionally surgery. If a tumor near the cribriform is causing the individual to lack
olfactory abilities, then surgical removal and radiation is typically the course of treatment. However,
in causes where anosmia resulted from head trauma or undiagnosed causes there are no current
treatment options.
Additional

Difference Between Pepsi And Coca Cola
Introduction: The human body can do some amazing things such as be able to taste the difference
between Pepsi and Coca Cola all because of the structure and function relationship in our senses. We
sense the world through sensory receptors that function for chemicals, light, temperature,
mechanics, pain and positions. Every time you take a bite of food, receptors in your mouth called
taste buds pick up the taste of the food you are eating. These receptors are sensitive to five basic
tastes: umami (a savory flavor), salty, sweet, bitter and sour. But right above your mouth is your
nose, which also plays a part in how you experience food. The nose is equipped with millions of
receptors for odor molecules. You can smell a food by sniffing ... Show more content on
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If they are blindfolded, they will also be more likely to be incorrect in predicting the correct flavor.
Experimental Design:
We tested twenty students of all ages and gender. All the data was recorded in a table with the
predictions under each different student and test. The materials that we used were three different
flavored jelly beans, a blindfold, and water to cleanse palates. The key concepts of this experiment
were vision, olfaction, and gustation. We want to see how well we can taste if we can't smell.
Procedure A: consisted of test subjects, who were given a red delicious apple jelly bean. Our
prediction was that the subject would identify the jelly bean as a strawberry flavor, by just the
appearance. Next, the subjects crushed the jelly bean, to help release some of the molecules inside,
trying to determined the flavor. Lastly, the student tasted the candy and gave their final guess of the
flavor. Procedure A was repeated many times with different students. In between the three different
tastings, students were given water to cleanse their palates.
Procedure B: consisted of the students being blindfolded, so there is no visual connections that could
have helped them properly identify it. The students were able to smell the jellybean and make their
first prediction then tasted it to make a second prediction. We wanted to see if they could identify
the correct flavor without using all their senses.
Procedure C: consisted of

What is Olfaction?
Olfaction And Pheromones What is Olfaction? Olfaction is another word or a synonym used for the
ability to smell or smell that anything carries with itself. It is by far one of the oldest senses that
human and animals have carried likewise for ages. It allows organisms to identify food, as well
allows them to copulate and evade the threat and danger posed by other predators besides providing
sensual as well as warnings of danger pleasure. For both humans and animals, it is one of the
important means by which our environment communicates with us and they communicate with it
vice versa. So in other words it is the means via which one is able to interact with whatever is
around us. In light of what has been mentioned in this very brief paragraph imagine what it would
be like if there was no sense of olfaction? What are odors (examples)? The odor of flowers and
perfume, smell of danger like smell of something burning, intoxicants, smell of food and spiciness,
smell of something being stale or dead and even smell of someone that you know as being around
you through their body scent and perfumes. Animals often mark their territories by smell and young
animals are able to trace their mothers through the same sense of smell while they are unable to see.
Detection of Odorants What is an Odorants? These are nothing more than the chemical components
that are present in the air and are carried through the air as and when we inhale and exhale air. The
molecular structure is so

Physio Ex 9.0 Exercsie 3
PhysioEx 9.0
Exercise 3
Neurophysiology of Nerve Impulses
A C T I V I T Y 1 The Resting Membrane Potential
1. Explain why increasing extracellular K_ reduces the net diffusion of K_ out of the neuron through
the K_ leak channels.
Increasing the extracellular potassium reduces the concentration gradient, and less potassium
diffuses out of the neuron and into the cell.
2. Explain why increasing extracellular K_ causes the membrane potential to change to a less
negative value. How well did the results compare with your prediction?
_______________________________________________________________________
A lesser amount of Potassium ions diffuse out across the membrane, leaving behind a less negative
charge. The ... Show more content on Helpwriting.net ...
Lidocaine binds to voltage–gated sodium channels, and prevents the flow of sodium ions. TTX
irreversibly blocks voltage–gated sodium channels. Lidocaine is slow at reacting and eventually
wears off.
3. A nerve is a bundle of axons, and some nerves are less sensitive to lidocaine. If a nerve, rather
than an axon, had been used in the lidocaine experiment, the responses recorded at R1 and R2 would
be the sum of all the action potentials (called a compound action potential). Would the response at
R2 after lidocaine application necessarily be zero? Why or why not?
With a compound action potential, the results would not necessarily be zero because some axons
could remain unaffected. Since lidocaine is a sodium channel blocker, it stops sodium ion channels
from working, preventing the generation of an action potential.
4. Why are fewer action potentials recorded at R2 when TTX is applied between R1 and R2? How
well did the results compare with your prediction?
TTX blocks the propagations of the action potential from R1 to R2. There are fewer action
potentials because of irreversibility, and the blockage of the voltage gated channels.
5. Why are fewer action potentials recorded at R2 when lidocaine is applied between R1 and R2?
How well did the results compare with your prediction?

Because lidocaine blocks the propagation of the action potential from R1 to R2
6. Pain–sensitive neurons (called nociceptors) conduct action potentials

Describe The Process Of Smell
The process of smell in medical terms is called Olfaction. The olfactory system allows the brain to
detect odorants, or chemicals in the air, that turn into signals which our brain can then use and
interpret. Every smell has its own emotional response that triggers a memory. Certain smells can
lead to different responses such as the need to fight or flight in the event of an emergency. When you
smell something that gives you a memory, you do not think about how the scent is taken to your
brain; it just happens. It is actually a very complicated process that involves many pathways and
receptors that all reach back to the command center of your body; the brain (Amerman, 2016). The
process of olfaction begins in the olfactory epithelium which ... Show more content on
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The odor must pass through the epithelial cells located in each nasal cavity by means of a large
inhalation of air through the nose. Once the odor passes through the epithelium, it must pass through
the mucous from the cilia by odorant–binding proteins. When the g–protein is activated it triggers a
converted form of adenylate cyclase into cAMP which opens ion channels allowing calcium and
sodium ions to enter the cell. This process turns the odor into a neural signal the brain can then
interpret. Once this signal is created, the axons of olfactory neurons carry the stimuli to the olfactory
bulb and then to the primary olfactory cortex within the temporal lobe. This process can take just a
few seconds through the rapid firing of synapses within the receptors. The processing of an odor
leads to a reaction depending on the type of scent being processed. Olfaction is just one of the five
special senses that make up how stimuli is perceived on a daily basis (Amerman,

Bell's Palsy Case Study
An example of a neurological disorder which has a taste disruption associated with it would be
Bell's Palsy. CN VII is affected in Bell's palsy, and this disruption affects taste perception. The
chorda tympani nerve is vitally important in the pathogenesis of Bell's palsy. Gustatory changes
have been noted a couple days prior to the onset of the Bell's palsy. These taste abberations were
likely experience due to changes in sensory reception from the tastes buds located in the anterior 2/3
of the tongue (fungiform papilla, which responds to sweet and sour taste). A reduction in taste
sensation has also been noted in patients with Bell's palsy. However, it is important to note that only
taste buds on half of the tongue will be affected, since ... Show more content on Helpwriting.net ...
It is important to note however, that these sense are unique. For instance, there are many more
smells the human body can discern, compared with a concrete number of tastes. In the olfactory
system, each cell has one receptor type. To that end, each smell we breath in evokes a different
expression pattern, which explains the myriad of smells we can discern. This is in stark contrast to
our gustatory system, where many different tastants we place on our tongues can stimulate the same
neurons, leading to a reduced perception in the number of various tastes.16
That being said, smell and taste do work intimately together. The sense of smell can reach the
olfactory sensory neurons via two different means. The first is via the nose, and the second is via a
"channel" which connects the "roof of the throat to the channel". If the pathway is physically
blocked (ie: You have a cold) then the odorants are unable to reach the sensory cells and your
perception of the "flavor" of your food is also diminished. Per a study conducted by Small et al,
these sensory components are "functionally united when anatomically separated."17 She writes,
"flavor perception depends upon neural processes which occurs in various parts of the brain
(anterior insula, orbitofrontal cortex, cingulate cortex and frontal operculum)."17 Furthermore,
Small goes on to say that "the

The Olfactory: The Chemistry Of Smell
The Chemistry of Smell In this paper I will be writing about the chemistry of smell. First and
foremost I want to define exactly what smell is. Smell is the faculty or power of perceiving odors or
scents by means of the organs in the nose. A smell can bring on an overflow of memories, influence
people's moods and even affect their work performance but what actually is smell? Have you ever
thought about it? Imagine trying to describe the smell of a rose to someone who has never possessed
the ability to detect odors. How exactly would you do this? The scientific term for the action of
smelling is called the olfactory process and in the olfactory process there is the olfactory nerve
which is also known as simply CN I . Olfactory practices are very hard to describe even to people
who have no olfactory problems. ... Show more content on Helpwriting.net ...
It communicates sensory data to the brain, and it shelters the sense of smell. Within the nasal cavity,
the nerve's olfactory receptors, are found inside the mucosa. Different to many other nerves, CN1
does not have two trunks. Rather, its sensory fibers range through the ethmoid bone's cribriform
plate. Once aerial substances and particles enter the nasal cavity, they interact with these neural
receptors. While part of the nervous system, the CN1 does not link to the brainstem. Only the optic
nerve joins the olfactory nerve in this difference. Also, CN1 is the shortest cranial nerve within the
human head. It can be prone to abrasions created by blunt trauma injury, which can result from
problems of frontal brain lobe tumors, meningitis, and a few other reasons. This will lead to a
reduced sense of smell. However, even if CN1 is damaged, nasal pain will still be communicated
through the trigeminal nerve. Olfactory receptor neurons are continuously born in life and just form
new axons to the neuron bulb. Application to Society and

Qualitative Smell Disorders
Mint is distinctively sharper and cooler than a pine tree. Sushi is a clean smell, with a combination
of sweet rice and subtle notes of ginger and lemon. An apple pie has the scent of summer because of
the warmth of the cinnamon and nutmeg. Christmas is earthy mixed with a hint of sharp, clean
aroma. Books are musty yet crisp, similar to a hundred–dollar bill. A dog's pungent breath smell
much like corn chips and hot dogs. Blood is an acrid, sweet, metallic aroma. Lavender is floral and
has herbal notes with balsamic undertones. Ocean water is overwhelming and heavy.
As much as I would want to, I can't smell any of that and I probably never will. I will never know
the true taste of chocolate or cheese. I will never be able to eat cooked oatmeal ... Show more
content on Helpwriting.net ...
If medication is the cause, doctors may be able to lower the dosage or change the medicine itself to
reduce the effect(s). Surgery will be needed to remove any nasal obstructions that restrict the airflow
to the nose. Aromatherapy is another useful tool for recovering smell. Although some individuals are
able to recover their sense of smell spontaneously, for no obvious reason, most are not so lucky.
When a complete recovery is not possible, there are dire

Essay on The True Relationship Between Taste and Smell
Introduction
It has been alleged that the perception of flavor and aroma are "derived from the senses of chemical
irritation, taste and smell" (Rawson, 2003). Collectively, these senses constitute what has been
termed chemosensation, even though these sensory systems are supposedly very different in their
physiology and anatomy. Nevertheless, they do have the ability to "regenerate, and their noted
susceptibility to aging and age associated diseases" (Rawson, 2003). In the article Is age related
olfactory loss uniform across odorants? It has been reported that nearly one third of all older persons
report displeasure with their sense of smell and taste, and the actual occurrence of sensory loss
amongst the elderly is maintained to be ... Show more content on Helpwriting.net ...
Loss within the sensory system can be attributed to changes in structural anatomy such as loss of
olfactory receptor cells or taste buds, changes or variance in the levels of particular receptor proteins
or ion channels, or environmental changes surrounding the receptor cell such as changes in the
composition of mucus in the nasal passages or reduction in salivation. An example of loss within
sensory system provided by researcher Nancy Rawson in her (2003) article "Age Related Changes
in Perception of Flavor and Aroma". This paper proves the use of dentures as they have the ability to
contribute to changes in taste perception because of the physical barrier to some of the membranes
where receptors reside, reduced salivation and the exposure of the receptors to compounds that the
dental adhesive tends to release. Chronic diseases are also posited as impactful on sensory
functionality, particularly cancer and diabetes, or even therapeutic interventions such as radiation,
surgery and certain medications. In many instances, what causes chemosensory loss is undetermined
and is often untreatable until the cause is determined and more is known regarding the age related
factors that lead to such phenomenon. Researchers have also posited that deficits in sensory
perception may be indicative of neurological disorders such as Alzheimer's disease

Fruit Fly Lab Report
Properly developed antennae of a fly containing different kinds of olfactory receptors allow the fly
to use small amounts of smell for orientation towards resources like oviposition sites, food or mates.
Scientists at one of the Chemical Ecology at Max Planck Institute in Jena Germany had used
mutated flies and proved that the extremely sensitive olfactory system of the fruit flies.
The flies can detect thousands of odor molecules para milliliter of air, but the human needs large
size of the air to do so. This is based on self–regulation the fly's odor receptors. Even when there
fewer molecules below the response rate, a fly can amplify the sensitivity of the receptors and the
binding molecules thus triggering the opening of an ion channel. ... Show more content on
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The shape is cuticle–covered appendages that contain approximately 120 and 1200 olfactory
receptors neurons (Wellerdieck et al., 1997; Zhao et al., 1998).
The smell that pass through pores on sensillum combine to ORs expressed on the dendrites of
ORNS and induced an action potential that can be monitored using the single sensillum recording
technique (Bestmann et al., 1996: Stensmyr et al., 2003). Through the performing the single
recording of the sensillum, a recording electrode is usually placed in the chosen sensillum and
captures the voltage changes due to the firing of the ORNs. The content of sensillum is more than
one ORN. Thus, the recording trace primarily represents the summed activity of all the available
neurons housed within the individual sensillum.
From the study of the operation of the olfactory neurons of a fly, the scientist decided to come up
with tiny gas analyzers. A scientist from Massachusetts Institute of Technology (MIT) came up with
a tiny sensor that could be used to detect small quantities of dangerous gasses that include toxic
industrial chemical much faster than the current devices. The engineers have used conventional
techniques known for gas chromatography and mass spectrometry and made them fit into a device
the made of the same size as a computer mouse. "Everything we are doing has been done on a
macro scale. We are just scaling it down," Said Professor

Neuron Synthesis
The papers Integrating the molecular and cellular basis of odor coding in the Drosophila antenna
and The receptors and coding logic for bitter taste try to understand how sensory neurons interacting
with chemicals produce the sensation of smell or taste in the brain. With chemosensation, a chemical
molecule binds to a receptor neuron, where transduction occurs. An action potential can be
generated which can travel along interneurons until it reaches the brain, which can process the
information and perceive a specific smell or taste. While all the steps from reception to perception
are important, both papers focus on receptor neurons and their role in chemosensation. Integrating
the molecular and cellular basis of odor coding in the Drosophila antenna looks at mapping the
olfactory system using Drosophila as a model organism. Or genes encode olfactory receptor neurons
(ORNs) which map to a neuron class. The neuron projects to a specific glomerulus, and the signal
eventually gets to the brain. This paper demonstrates three methods of mapping a receptor to a
neuron and odor and uses them to show that Or22a receptor maps to the ab3A neuron and that Or47a
receptor maps to the ab5B neuron. Dobritsa et al. also found ... Show more content on
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Beyond that, however, these papers are not explicit in describing the importance and application of
chemosensation research, especially the paper using Drosophila. In most cases, animal models are
used to understand processes within humans, but
Dobritsa et al. acknowledge two important differences between human and Drosophila olfactory
systems – that axonal pathfinding of ORNs to glomeruli occur at different life cycle stages and that
the number of ORNs in glomeruli differ by more than an order of magnitude. Question arise about
how much of the insight gained from these papers can be extended to humans as well as other
sensory

Chemical Smell

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Chemical Smell