physiology: neurophysiology

Question 1

what makes up the neuron?

Answer 1

Cell body
dendrites
axon hillock
axon
saltatory conduction (nodes of ranvier) if myelinated

Question 2

what is an action potential do?

Answer 2

change in permeability of membrane

Question 3

the resting state?

Answer 3

before AP begins
neg. on the inside
pos. on outside
membrane is polarized at -90 millivolts (mV) membrane potential

Question 4

depolarization stage?

Answer 4

depole >ascending phase
influx of sodium by fac. diff makes inside more positive; -90 mV is immediately neutralized
threshold occurs at -55 mV & -50 mV

Question 5

when Calcium is released?

Answer 5

it releases NT!!

Question 6

repolarization stage?

Answer 6

occurs at 10,000 of a second
na+ channels begin to close and K+ channels open wider
rapid diffusion (efflux) of K+ to exterior- re-establishes normal negative resting membrane potential
Repole> descending phase

Question 7

voltage-gated sodium channels?

Answer 7

two gates - one outside called activation gate
one inside called inactivation gate
at -70 to -50 mV activation gate flips open; na+ ions pour in. the inactivation gate will then slowly close; this will not open again until membrane potential is at or nearly at resting membrane potential.

Question 8

Axodendritic synapses?

Answer 8

MC synapse from axon to dendrite

Question 9

what are gap junctions?

Answer 9

tunnels to connect cytosol of 2 cells

Question 10

chemical synapses?

Answer 10

close together but do not touch
synpatic cleft is space bwn- need NT
synaptic delay of 0.5 m/sec
one way transmission- only synaptic end bulbs of presynaptic neurons release NT

Question 11

NE ttransmitter?

Answer 11

brain stem, hypothalamus, etc. excitatory

Question 12

glutamate NT

Answer 12

CNS, cerebral cortex excitatory

Question 13

nitric oxide NT?

Answer 13

brain excitatory

Question 14

ACH ??

Answer 14

inhibitory; motor cortex

Question 15

dopamine?

Answer 15

inhibitory; substantia nigra

Question 16

Glycine?

Answer 16

inhibitory; spinal cord

Question 17

GABA?

Answer 17

inhibitory; spinal cord, cerebellum, basal ganglia

Question 18

serotonin?

Answer 18

inhibitory; brain stem

Question 19

what is summation?

Answer 19

1,000-10,000 synapses recieved in CNS

Question 20

spatial summation is?

Answer 20

buildup of NT released- several presynaptic bulbs

Question 21

temporal summation is?

Answer 21

NT releases- single presynaptic bulb; fires 2x or more

rapid succession of AP with only a few synapses

Question 22

what are pain receptors?

Answer 22

nociceptors- free nerve endings; sense pain, tickle, itch, temp.
located greatest number: tongue, lip, genitalia, finger tips
least in number: upper arm, buttock, trunk

Question 23

mechanoreceptors sense?

Answer 23

pressure- end bulbs of krause
corpuscles of ruffini- pressure, temp, 2-5 degrees perception
both are encapsulated

Question 24

merkels discs?

Answer 24

general touch, hair follicles- not encapsulated

Question 25

meissners corpuscles?

Answer 25

fine touch, nonhairy skin, encapsulated

Question 26

pacinians corpuscles?

Answer 26

pressure, vibration, encapsulated "phasic receptor"

Question 27

muscle spindles?

Answer 27

detect stretch- dynamic & staic only in skeletal muscle

Question 28

GTO?

Answer 28

load or weight

Question 29

golgi tendon reflex?

Answer 29

prevents excessive tension in a muscle

Question 30

Sympathetic has what affect on the body??

Answer 30

``` flight or fight BV-vasoconstricts HR- increases rate Lung- deep breaths Bronchi- dilates bronchi Eyes- dilates GI- decreases digestion & secretion recpetors- Adrenergic PREgang.- ACH- short POSTgang.- EPI/NE- long ```

Question 31

Parasympathetic has what affect on the body?

Answer 31

``` Rest & digest BV- little to no effect Muscle- yes Heart- decreases rate Lung- shallow breaths Bronchi- constricts GI- Increases secretions & bowel movement Receptors- Cholinergic PREgang.- ACH- long POSTgang.- ACH- short ```

Question 32

what is absolute refractory?

Answer 32

NO A-P available

Question 33

what is Relative Refractory?

Answer 33

A-P available with increase in potential

Question 34

Influx of sodium means?

Answer 34

depolarization

Question 35

efflux of potassium means?

Answer 35

repolarization

Question 36

Somatosensory area is?

Answer 36

postcentral gyrus in the parietal lobe

Question 37

Visual sensory area is in?

Answer 37

occipital lobe, striate cortex, calcarine fissure

Question 38

Auditory sensory area is in?

Answer 38

superior temporal lobe, Heschl's gyrus

Question 39

Gustatory (taste) sensory area is in?

Answer 39

base of postcentral gryus

Question 40

Olfactory sensory area is in?

Answer 40

medial temporal lobe

Question 41

wernickes is?

Answer 41

the recepetive portion of language in the Superior Temporal Lobe

Question 42

Motor area is in?

Answer 42

Precentral gyrus in the frontal lobe

Question 43

premotor area is in?

Answer 43

skilled movements- anterior to motor cortex

Question 44

Brocas area is in?

Answer 44

Expressive portion of language- inferior posterior frontal lobe.

Question 45

where does Coordination of muscle contractions take place? clinical?

Answer 45

``` Cerebellum- SIN Staccato/Slurred speech Intention tremor Nystagmus ```

Question 46

where is Crude sensation relayed?

Answer 46

Thalamus- main relay bwn cortex & spinal cord

Question 47

What does the hypothalamus control?

Answer 47

``` ANS & endocrine system body temp., food intake, thirst rage & aggression maintains waking state & sleep releases somatstatin- inc. insulin & glucagon ```

Question 48

what does the Limbic system do?

Answer 48

emotional aspects of behavior related to survival | including the: Fornix, Hippocampus, cingulate gyrus, Amygdala, Parahippocampal gyrus & parts of the thalamus

Question 49

what does the superior colliculi do?

Answer 49

coordinates the eyeball movement in response to visual stimuli located in the midbrain

Question 50

what does the inferior collicul do?

Answer 50

coordinates head & trunk to auditory stimuli Located in the midbrain CN III,IV EAR

Question 51

where is breathing associated with? Pons or medulla?

Answer 51

Pons Pneumotaxic & apneustic centers located here CN V, VI, VII, VIII

Question 52

which area functions in consciousness & arousal?

Answer 52

Medulla- reticular formation Vital reflex centers regulate HB, breathing, & BV diameter Coordinates- swallowing, vomiting, coughing, sneezing, & hiccuping. Vestibular nuclei- maintain equilibrium CN VIII, IX, X, XI, XII