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Flashcards in Exam 3 Deck (65):
1

What is a muscle twitch?

a quick cycle of contraction when stimulus is at threshold

2

What is anaerobic fermentation?

enables cells to produce ATP when there is no oxygen around

3

What is aerobic respiration?

produces more ATP than anaerobic and requires oxygen

4

What is a slow twitch?

smaller and is more resistant to fatigue

5

What is a fast twitch?

larger and has a poor fatigue resistance

6

What are the 6 sources of muscular fatigue?

1. ATP synthesis
2. Less effectiveness of sodium potassium pumps
3. Lactic acid build up
4. Motor neurons using up ACh
5. Potassium diffusion
6. Weaker central nervous system

7

What are sensory neurons?

Afferent-- Receive stimuli from environment and transmits to CNS

8

What are motor neurons?

Efferent-- receives stimuli from CNS and transmits to body

9

What do interneurons do?

connect the sensory and motor neurons

10

What is a neuron?

A nerve cell

11

What is a nerve?

A bundle of nerve fibers

12

What is a ganglion?

A knot-like swelling nerve

13

What does the Central Nervous System consist of?

Brain and spinal cord

14

What does the Peripheral Nervous System consist of?

Everything except brain and spinal cord

15

What are the three divisions of the autonomic nervous system?

visceral, sympathetic, and parasympathetic

16

What are multipolar neurons?

one axon and many dendrites

17

What are bipolar neurons?

one axon and one dendrite

18

What are anaxonic neurons?

No axon and many dendrites

19

What are neuroglia?

Protect and aid neurons

20

What are the 6 types of neuroglia?

oligendrocytes, astrocytes, ependymal cells, microglia, schwann cells, and satellite cells

21

What do oligodendrocytes do?

Create myeline sheath

22

What do astrocytes do?

cover brain surface

23

What do ependymal cells do?

line internal cavities

24

What do microglia do?

consume debris in central nervous system

25

What do schwann cells do?

create myelin sheath

26

What do satellite cells do?

surround soma of neurons

27

Why is myelin important?

insulates the nerve fiber

28

What are the 3 steps of an axon regeneration?

1. consumed by macrophages
2. axon stump grows sprout
3. regeneration tube guides prout

29

What is resting membrane potential?

polarized membrane due to high conentration of anions outside and cations inside

30

What is local potential?

When a dendrite receives neurotransmitters

31

What is action potential?

When local potential reaches trigger zone

32

What is the refractory period?

Period of resistance to stimuli

33

What is a synapse?

Junction between neuron and target cell

34

What are the 4 forms of neurotransmitters?

acetylcholine, amino acids, monoamines, and neuropeptides

35

What are the 3 steps involved in cholinergic synaptic transmissions?

1. action potential arrives
2. calcium ions enter synaptic knob
3. empty vesicles retreat into cytoplasm

36

What is ionotropic effect?

neurotransmitter opens ion gates and changes membrane potential

37

What is metabotropic effect?

Neurotransmitters alter metabolism to creat cAMP

38

What are the 3 means of removing neurotransmitters?

diffusion, reuptake, and degradation

39

What is EPSP?

Excitatory postsynaptic potential?

40

What is IPSP?

Inhibitory postsynaptic potential?

41

What is summation?

Responding to the net effect of postsynaptic potential

42

What is temporal summation?

One single synapse generated quickly to get to threshold

43

What is Spatial summation?

several synapses generate threshold

44

What is qualitative information?

which neurons are firing

45

What is quantitative information?

how many neurons are firing

46

What are the three meninges?

Dura metter (most superficial), arachnoid mater, and pia matter (deepest)

47

How many spinal nerve pairs are there?

31

48

What are the 4 structures of the spinal chord?

cervical, thoracic, lumbar, and sacral

49

What is the ascending tract?

carry info up spinal chord to brain

50

What is the descending tract?

carry info down spinal cord to body

51

What are the 3 functions of cerebrospinal fluid?

buoyancy, protection, and chemical stability

52

Where does cerebrospinal fluid come from?

fuels external surfaces of the central nervous system

53

Why is it important to keep whole blood from touching the central nervous system?

to prevent toxins from entering

54

Whats the blood-brain barrier?

found in capillaries in brain tissue

55

What is the blood CSF barrier?

formed by junctions between ependymal cells

56

What are the 5 plexuses?

cervical, bracial, lumbar, sacral, and coccygeal

57

What are proximal branch of the spinal nerve?

spinal nerves have 2 points of attachment

58

What are the distal branches of the spinal nerve?

spinal nerves have 3 branches

59

Whats a dermatome?

areas of skin that send sensory info

60

What are the 4 characteristics of reflexes?

stimulation, quick, involuntary, and stereotyped

61

What type of neurons are found in the roots of spinal nerves?

interneurons

62

What does ipsilateral mean?

on the same side of the body

63

What does contralateral mean?

on opposite sides of the body

64

What are the 4 steps of contraction?

1. Active sites exposed, ATP binds to myosin heads. Myosin ATPase in head break down ATPADP and phosphate group. Myosin head moved into extended starting position
2. Myosin head binds to active site on actin filament/ forms a cross bridge.
3. Myosin releases ADP/ Phosphate group. Head flexes to bent position, drags actin filament with it (power stroke). Stays bound with actin till new actin molecule binds with head.
4. ATP binds with myosin head, breaks bond between actin/myosin. Myosin ATPase breaks ATPADP/ phosphate group. Returns to extended position (recovery stroke). Steps 2-4 repeat.

65

What are the 5 steps of relaxation?

1. Nerve signals stop stimulating neuromuscular junction and the synaptic knob stops releasing Ach.
2. AChE breaks down ACh and the Ach receptors close their gates. Synaptic knob reabsorbs the Ach fragments for recycling. Action potentials stop and stimulus to contract the muscle cells stops.
3. Active transport pumps in sarcoplasmic reticulum return calcium ions from cytosol to terminal cisternae. ATP is required to relax muscle fibers.
4. Calcium is removed from troponin and pumped back into SR.
5. Troponin-tropomyosin complexes cover active sites of actin again. Myosin can no longer bind to actin; muscle fiber loses tension and returns to resting length due to titin, tendons, and muscles.