B2W4 Med Phys

Question 1

Hair Cell Structure

Answer 1

All hair cells have stereovilli
Type 1 cells have stereovilli and Kinocilium on the tallest end
Type 2 Cells only have stereovilli

Question 2

Type 1 Hair Cells

Answer 2

Stereovilli are arranged from short to tall and connected via cadherins
The tallest kinocilium is not connected via cadherins

Question 3

Type 2 Hair Cells

Answer 3

Stereovilli are arranged from short to tall and starting from the second tallest stereovilli down are connected via cadherins

Question 4

Cadherins Opening and closing

Answer 4

When hair cells are bent towards the long end the cadherins undergo tension
When hair cells are bent towards the short side the cadherins are relaxed

The more tense the cadherin the more potassium flows into the cell

Question 5

Endolymph

Answer 5

Cytosol like fluid
High K+, Low Na+
Bathes the stereovilli

Question 6

Perilymph

Answer 6

CSF like fluid
High Na+, Low K+
Located on the basolateral portion of hair cells

Question 7

Auditory Neurotransmitter

Answer 7

Glutamate

Question 8

Vestibular neurotransmitter

Answer 8

Glutamate and Aspartate

Question 9

Positive and negative deformation of hair cells

Answer 9

Positive
- Toward tall side
- K+ Channels Open
- K+ Influx

Negative
- Toward short side
- K+ Channels close
- Cell hyperpolarizes

Question 10

Vestibule Cochlea Anatomy

Answer 10

Cochlea is snail like spiraling structure
Vestibula is made of the otolith organs and semicircular canals

Question 11

Otolith Organs

Answer 11

Organs responsible for the detection of gravity, linear movement, and horizontal movement.

Question 12

Utricle

Answer 12

Detects horizontal movement
Hairs radiate from tall to short

Question 13

Saccule

Answer 13

Detect vertical movement
Hairs radiate from small to tall

Question 14

Semicircular Canals

Answer 14

Detect head rotation

Question 15

Ampullae

Answer 15

Detect rotational acceleration

Question 16

Impeding Matching Device

Answer 16

Tympanic Membrane in the ear along with the ossicles convert air pressure into fluid pressure
30:1 surface area of tympanic membrane to oval window

Question 17

Cochlea Frequency

Answer 17

Base of the cochlea
- Stiff and narrow
- Detects high frequency

Apex
- wide and floppy
- detects low frequency

Question 18

Helicotrema

Answer 18

Apex of basilar membrane where perilymph of scala vestibuli and scala tympani communicate

Question 19

Process of Cochlea audio detection

Answer 19

Sound transferred into oval window -> Moves fluid in scala vestibuli -> Fluid in scala tympani moves in the opposite direction -> Scala Media moves and opens hair cells

Question 20

Inner Cochlea anatomy

Answer 20

Oval Window Side to Round window
Scala Vestibuli -> Reissner’s Membrane -> Scala Media -> Tectoral membrane and Basilar membrane -> Scala Tympani

Question 21

Physiology of hearing

Answer 21

K+ channels open allowing for K+ from scala media endolymph to enter the cell -> Causes contraction in prestin protein -> Prestin protein causes outer hair cells to contract -> Outer hair cells move basilar membrane to increase endolymph upward movement -> More endolymph causes more stereovilli to bend positively and depolarize -> Ca2+ channels open and enter the cell -> Release of glutamate into the auditory cochlear nerve

Question 22

Thermoreceptors

Answer 22

Senses cold and hot

Question 23

Heat Receptor

Answer 23

TRPV1-4
Capsaicin Receptor

Question 24

Cold Receptor

Answer 24

TRPM8
Menthol Receptor

Question 25

Tissue Damage Response

Answer 25

Causes release of inflammatory soup

Question 26

Noiceceptors

Answer 26

Detect pain

Question 27

Spinal Circuit

Answer 27

Sensory information enters from the dorsal root ganglion -> follow dorsal root into the spinal cord -> Axon splits into two or more synapses -> signal travels to both alpha motor neurons and interneurons

Question 28

Interneurons in the spine

Answer 28

Can inhibit or excite muscles and detect which muscles need to be fired

Question 29

Myotatic Knee Jerk Reflex

Answer 29

Patellar tendon stretches -> stretches quad muscle -> stimulates muscle spindles -> afferent signal travels to spinal cord via dorsal horn -> Afferent axon splits and one (Monosynaptic) axon synapses with alpha motor neurons of the quad to stimulate it Other axon ends synapse onto inhibitory interneurons (Polysynaptic) and inhibit the hamstring muscle

Question 30

Golgi Tendon Reflex

Answer 30

Type 1b afferent neurons from golgi tendon organ senses shortening of muscle -> synapses onto interneurons (Polysynaptic) -> interneurons inhibit motor neurons of contracting muscle -> stimulate antagonistic muscle P Think prevent too much squeezing

Question 31

Flexion - Withdrawal Reflex

Answer 31

Noxious stimulus activate delta afferent nociceptor -> synapse with multiple interneurons (Polysynaptic) -> in the limb that this happened flexion is stimulated and extension is inhibited -> in opposite limb stretching is stimulated and flexion is inhibited

Question 32

Layer 4 of Primary visual cortex

Answer 32

Projects to other layers and striate cortex Both eyes visual information converges

Question 33

Layers 2 and 3 of visual cortex

Answer 33

Have blobs that detect motion or color

Question 34

High Frequency Sound Localization

Answer 34

CNS measures the change in sound intensity from one cochlea as compared to the other

Question 35

Low Frequency Sound Localization

Answer 35

CNS measures the time it takes for sound to reach both cochlea