Physio Lab exam 2

Question 1

What factors affect RMP?

Answer 1

Sodium/Potassium pump (3 Na+ out, 2 K+ in), K+ leak channels

Question 2

What factors affect release of NT?

Answer 2

Presynaptic membrane undergoes exocytosis

Question 3

How does Lidocaine work?

Answer 3

Blocks the conduction of action potentials by binding and blocking the voltage gated Na+ channels to prevent action potentials.

Question 4

Why didn’t curare block the AP?

Answer 4

it is an alpha-toxin that binds to acetylcholine binding sites on the postsynaptic cell membrane, which prevents the acetylcholine from acting. Curare blocks synaptic transmission by preventing neural impulses to flow from neuron to neuron. It does allow the action potential to travel in the axon, it just doesn’t pass it on to the dendrite.

Curare competes with ACh for attachment to the nicotinic ACh receptors

Question 5

What factors affect action potential velocity?

Answer 5

Myelin sheath, temperature, axon diameter

Question 6

When does spatial summation occur?

Answer 6

As a result of the convergence of presynaptic axon terminals on the dendrites and cell body of a postsynaptic neuron

Question 7

What is an EEG?

Answer 7

The recording of electrical activity on the scalp.

Question 8

How is EEG administered?

Answer 8

By placing electrodes on the scalp

Question 9

EEG’s are used to diagnose…

Answer 9

epilepsy, other abnormal states

the absence of an EEG can be used to signify brain death

Question 10

Alpha waves are best recorded from ____ and _____ regions while a person is _____ and relaxed.

Answer 10

parietal, occipital, awake

Question 11

Beta waves are strongest from the _____ lobes, especially near the ______ gyrus

Answer 11

frontal, precentral.

Question 12

How are beta waves produced?

Answer 12

By visual stimuli and mental activity

Question 13

Theta waves are emitted from the ____ and _____ lobes and are common in _____ and _________.

Answer 13

temporal, occipital. Common in newbord infants/adults. Recording of theta waves in awake adults indicates severe emotional stress.

Question 14

Delta waves are emitted in a ______ pattern from the ________

Answer 14

general, cerebral cortex. Delta waves are common during sleep and in an awake infant. Presence of delta waves in an awake adult indicates brain damage.

Question 15

Chemoreceptors respond to

Answer 15

chemical stimuli

taste buds, olfactory epithelium

Question 16

Photoreceptors…

Answer 16

transduce light

rods and cones in retina or eye

Question 17

Thermoreceptors…

Answer 17

respond to temperature changes

Question 18

Mechanoreceptors…

Answer 18

respond to deformation of cell membrane

touch/pressure receptors in skin and hair cells within ear.

Question 19

Nocioceptors…

Answer 19

respond to intense stimuli by signaling pain

Question 20

Proprioceptors…

Answer 20

signal positional info of body parts.

Question 21

Cutaneous receptors include

Answer 21

touch & pressure receptors, heat/cold receptors, pain receptors.

Question 22

Function of receptor

Answer 22

they transduce (change) different forms of energy into the energy of nerve impulses that are conducted into the CNS by sensory neurons.

Question 23

Different forms of modalities include

Answer 23

sound, light, pressure,

Question 24

Define two point threshold

Answer 24

Minimum distance at which two points of touch can be perceived as separate. Measure of the distance between receptive fields.

Question 25

2 point threshold is indication

Answer 25

of tactile acuity, or sharpness of touch perception

Question 26

What are phasic receptors?

Answer 26

receptors that respond with a burst of activity when a stimulus is first applied, but then quickly decrease their firing rate-adapt to the stimulus- if the stimulus is maintained.

Pacinian corpuscle (pressure receptor)

Question 27

Define refraction

Answer 27

“bent” Light that passes from a medium of one density into a medium of a different density is refracted.

Question 28

define visual acuity

Answer 28

sharpness of vision

Question 29

Define myopia

Answer 29

Nearsightedness, image will focus in front of retina. Eyeball is too long. Corrected with glasses with concave lenses.

Question 30

Define hyperopia

Answer 30

far sightedness, eyeball is too short. Rays focus behind retina. Convex lens correct farsightedness

Question 31

Define astigmatism

Answer 31

Asymmetry of cornea, lens. Would not be able to look at a circle of stripes, part of stripes would blur. Corrected with cylindrical lenses.

Question 32

Define accomodation

Answer 32

The ability of the eye to keep the image focused on the retina as the distance between the eyes and object varies

Question 33

Define Nystagmus

Answer 33

Eyes involuntarily move left and right after spinning,

Question 34

What causes blind spot?

Answer 34

It is the result of the optic nerve connecting with the back of your eyeball. There are no light sensitive rods or cones here

Question 35

What is afterimage?

Answer 35

It is an optical illusion where the image still apears after seeing the picture

Question 36

Cones include

Answer 36

blue cones (s cones), red cones (L cones), green cones (M cones)

Question 37

What is sensorineural deafness?

Answer 37

transmission of nerve impulses anywhere from the cochlea to the auditory cortex is impaired

Question 38

What is conduction deafness?

Answer 38

transmission of sound waves through the outer and middle ear to the oval window is impaired

Question 39

what is isotonic contraction?

Answer 39

muscle is in constant tone, pulling same force, lifting something for example

Question 40

what is isometric contraction?

Answer 40

when muscle stays the same length even if force of contraction increases. for example, standing still

Question 41

what is eccentric contraction?

Answer 41

muscle acts like a brake. Muscle contracts but still extended. pushup!

Question 42

List what cells light passes through retina.

Answer 42

Fiber optic cells,
Ganglion cells
Amarine cells
Bipolar cells
Horizontal cells
Photoreceptors (rods/cones)