Chapter 10 - Sensory Physiology

Front 1

How does the CNS determine intensity of a stimulus?

Back 1

It increases the # of active receptors

Front 2

What is population coding?

Back 2

Multiple receptors function together to send central nervous system more info than a single receptor

Front 3

Frequency coding

Back 3

As stimulus intensity increases receptor amplitude increases in proportion and frequency

Front 4

Labeled line coding

Back 4

Association of a receptor with a sensation

Front 5

Tonic receptor

Back 5

Slowly adapting receptors that fire rapidly when first activated then slow and maintain their firing as long as the stimulus is present

Front 6

Phasic receptor

Back 6

Rapidly adapting receptors that fire when they first receive a stimulus but cease firing if strength of stimulus remains constant

Front 7

Name the type of sensory receptors responsible for pain and itch sensations

Back 7

Nociceptors

Front 8

What do histamine, prostaglandins, and P protein all have in common? What type of receptors do they bind to and what sensations they produce?

Back 8

They modulate nociceptor activity - they bind to sensory receptors and produce pain

Front 9

Explain the gate control theory of pain modulation... what blocks pain?

Back 9

Nonpainful stimuli can diminish pain signal...A- beta fibers block pain

1) absence of input from C-fibers finically active inhibitory interneuron suppressed pain pathway

2) w/ strong pain: C-fibers stop inhibition of the pathway, allowing a strong signal to be sent to the brain

3) pain can be modulated by simultaneous somatosensory input

Front 10

What results from the inhibition of adenyl cyclase in olfactory sensory neurons?

Back 10

Reduction of cAMP + reducing odorant response

Front 11

What steps happen in olfactory cells when G olf is activated that contribute to their depolarization?

Back 11

Increases intracellular cAMP which opens cAMP gated channels depolarizing the cell

Front 12

Name the signal transduction molecule that is released from type II cells and stimulates primary gustatory neurons:

Back 12

ATP

Front 13

What is umami?

Back 13

Taste associated w/amino acid glutamate and some nucleotides

Front 14

What is gustducin? Name the type of cells that produce it and describe what function it performs :

Back 14

Gustducin: G protein- produced by Type II cell receptors

Function: activates multiple signal transduction pathways which result in intracellular Ca2+ increases which initiates ATP release

Front 15

What determines loudness/intensity of a sound- what determines pitch?

Back 15

Frequency

Front 16

Define amplitude and duration

Back 16

Amplitude: intensity of a sound wave

Duration: how long a sound wave lasts

Front 17

Where are the ion channels that transduce the vibration of the cochlea into receptor potentials located?

Back 17

In the organ or corti

Front 18

What does the tympanic membrane do? How are sound waves converted into mechanical movement?

Back 18

Tympanic membrane separates external ear from middle ear

Front 19

What is the primary purpose of the 3 tiny middle ear bones?

Back 19

Conduct sound from the external environment to inner ear

Front 20

Compare the location and function of oval window and round window

Back 20

Oval window: connects middle ear w/upper half of cochlea ; transfers vibrations of audit Iott ossicles to cochlea via stapedial foot plate

Round window: connects middle ear w/ lower half of cochlea; aids fluid motion within cochlea and equalizes pressure

Front 21

What are hair cells? Where are they found and what do they do?

Back 21

They resonate pitch sounds- located in Basilar membrane

Front 22

What do the ciliary muscles do?

Back 22

Contraction alters curvature of lens

Front 23

What is the fovea?

Back 23

Region of sharpest vision

Front 24

Describe accommodation - how does the eye achieve this?

Back 24

Process by which the eye adjusts lens shape to keep objects in focus

Front 25

What is retinal ?

Back 25

Synthesized by vitamin A: light absorbing portion of rhodopsin

Front 26

What is Opsin?

Back 26

A protein embedded in membrane of the rod disks in rhodopsin- decreases cGMP

Front 27

What is rhodopsin?

Back 27

Activated by light- made up of opsin and retinal

Front 28

What is transducin?

Back 28

Made up of 3 G proteins

Front 29

Name the cells that are involved in processing visual information in the retina and synapse with rods:

Back 29

-mRGC

-cones

Front 30

Name the neurotransmitter secreted by photoreceptors

Back 30

Glutamate

Front 31

What is rhodopsin?

Back 31

Activated by light- made up of opsin and retinal

Front 32

What is transducin?

Back 32

Made up of 3 G proteins

Front 33

Name the cells that are involved in processing visual information in the retina and synapse with rods:

Back 33

-mRGC

-cones

Front 34

Name the neurotransmitter secreted by photoreceptors

Back 34

Glutamate

Front 35

Define presbyopia, cataract, astigmatism

Back 35

Presbyopia: loss of accommodation

Cataract: clouding I’d normally clear lens of eye- caused by breaking tissue and clumping of proteins

Astigmatism: cornea is not a perfectly shaped dome; images distorted

Front 36

Concave lens

Back 36

Hypertropia- takes light coming in and scatters it

Front 37

Convex lens

Back 37

Myopia: takes light in and focuse it to a certain point