General senses, and smell and taste lecture Flashcards
What is transduction?
It is the process of changing the stimulus in an action potential
What is phasic sense?
senses that adapt out over time
What is a tonic sense?
sense that do not adapt out over time
How long does it take a smell to fade?
50% of sense of smell adapted out in 1 second all by 1 minute
What is a Receptive field?
The size of the area feeding into same neuron
What is another name for the kind of stimulus?
The modality (i.e mechanoreceptor, baroreceptor)
How many neuron per cone?
1
How many rods per neuron in the eye
500-600
What are structural classification of sensory neurons
Free dendrite receptors, Encapsulated nerve endings, separate sensory cells
What modalities of receptors are Free dendritic endings?
All Noci and thermo, some,chemo some mechanoreceptors
How does a free dendridic nerve ending send its signal?
Graded receptors that will summated at the trigger zone
What modality of receptors are Encapsulated nerve ending?
Mechanoreceptors like corpuscles
What are the three classifications by location for receptors?
Exteroreceptors, interoreceptors, proproceptors
What does an interoreceptor do and can you feel them ?
Moniter internal environment like blood pressure, generally can’t feel them except for pain or pressure
Where do you find proprioceptors
muscles, tendons, joints and inner ear
Are Ruffnini Corpuscles tonic or phasic?
The are tonic and primarily for p
What are Merkel’s Disc and what are the for?
flattened dendritic cells touching the stratum basale. They are for discriminative touch. so not equally distributed.
What location classification of Ruffini corpuscles and are the tonic or phasic.
The are in all location and they are tonic
Where is a unique location and function for End bulbs of Krause
They are on upper lip and slow down heart rate dramatically. Measures rate of conductivity away from your body
All corpuscles are what type of receptors?
Mechanoreceptors
What temperature do cold receptors operate at?
50-105F
What temperature do warm receptors operate at?
90-118F
How do you perceive far hot and cold outside of the normal thermoreceptor range
As pain
How large is the receptor field for thermoreceptors, and what is their structural classification?
about 1mm. free dendritic endings
Nociceptors are a special kind of what receptor? What do they typical respond to
chemoreceptors. They responds to chemicals that are outside the cell that are usually inside.
What are common chemicals that stimulate nociceptors
Potassium, kinins, prostaglandins
What is the term for stimulating other receptors to relieve pain
Spinal gating
What part of the brain acts on acute pain to stop it from being felt?
the reticular formation
What is another name for “slow pain”
chronic pain
What is happening to ion concentration around cells in referred pain
The quick succession of signal cause depolarization in an area on the path of the pain the makes it feel that the pain if from the location. Ie arm in a hear attack on its was up to the brain
How do analgesics work on pain?
Nocieceptors don’t get a signal
How does novocaine or lidocaine work on Pain?
Block voltage regulated sodium channels. receptor works, but shuts down along axon.
How does morphine work on Pain?
It lessens or eliminates the perception of pain
How are Muscles spindles used in proprioception
When a muscles is stretched the muscle spindle shed the information to the CNS. This is tonic
Where do you find Golgi tendon organs and how do the work?
They are at the junction of muscle and tendon they really signals to CNS to relax the muscles when overstretched.
About how many different odors can humans identify?
10,000
how often do olfactory cells get replaced?
about every 60 days?
What kind of neurons are olfactory neurons?
bi polar
What kind of molecules can be smelled?
volatile water soluble molecules?
How does does the scent cause an action potential?
The compound binds to a ligand gated sodium channel.
Where is the olfactory cortex?
In the temporal lobe
What is the role of the habenular nuclei in smell?
It produces emotion based physiological response to smell, such as calm or agitation
Where are the Foliate papillae, what do the look like what do they do.
The are on the sides of the tongue and look clover shaped
Describe the location and test bud concentration Fungiform pappilae
They are on the anterior 2/3 of the tongue and have about 5 taste buds per papillae
Describe the location and test bud concentration of Vallate papillae
The are on the back of the tongue. Have 1/2 of all taste buds and about 250 taste buds per papillae
Describe the location and function of Filiform papillae.
They are for texture and are when the fungiform ones are
What kinds of neurons are gustatory cells?
bipolar
What stimulates the salt taste receptors
Sodium
What stimulates the salt taste receptors
Sodium. It is a direct depolarizer
What stimulates sour taste
Acids with protons. It is a direct depolarizer
What taste bitter. How is this sense propagated
Alkaloids, with an OH-. These use a second message system, for amplification. This allows for high bitter sensitivity.
How does umami work?
Binds to glutamate. It also uses a secondary messanger system
How does sweet work?
It uses a second messenger system, but how the binding works is not yet known.
What is a Synthetic sense?
Identifying a sense in its totality. All vision is synthetic.
What is a Analytical sense?
individual components of a sense
Are taste and small synthetic or analytical senses?
Both. Can identify a whole, or break down components.
