Skeletal muscle and nerve tissue

Question 1

What surrounds individual muscle fibers?

Answer 1

endomysium

Question 2

What are fascicles? what surrounds it?

Answer 2

groups of individual muscle fibers

perimysium

Question 3

What surrounds the entire muscle?

Answer 3

epimysium

Question 4

Where are the nuclei for skeletal muscle cells?

Answer 4

on periphery of cells

Question 5

What is the cytoplasm of muscle cells composed of?

Answer 5

myofibrils

Question 6

What are the two components of muscle cells that allow contraction?

Answer 6

actin (thin)

myosin (thick)

Question 7

What is a Z line? what is the area between two z lines called?

Answer 7

z lines are the anchoring points for actin filaments

z line to z line is a sarcomere

Question 8

What is a sarcomere?

Answer 8

the basic contractile unit of a muscle cell

Question 9

What is the I band composed of?

Answer 9

actin

Question 10

What is the M line?

Answer 10

anchor site for myosin (M line is in middle of thing)

Question 11

What contained in the H zone?

Answer 11

myosin

Question 12

What is the A band?

Answer 12

where actin and myosin overlap

Question 13

Where is calcium stored in muscle cells?

Answer 13

sarcoplasmic reticulum surrounding each fascicle

Question 14

What is the function of a T tubules?

Answer 14

allows the depolarization wave to move through the muscle tissue

Question 15

What is the terminal cisternae?

Answer 15

dilated ends of sarcoplasmic reticulum that releases calcium

Question 16

What is the relationship between myofibril and sarcomere?

Answer 16

myofibrils contain thousands of sarcomeres

Question 17

What is the function of tropomyosin?

Answer 17

wrapped around actin, covers of myosin binding sites until activated by troponin T

Question 18

What is the function of troponin C?

Answer 18

binds calcium

Question 19

What is the function of troponin T?

Answer 19

bind tropomyosin once troponin C binds calcium

Question 20

What is the function of troponin I?

Answer 20

inhibit muscle contraction

Question 21

what is happening on the macromolecular level during muscle contraction?

Answer 21

actin is sliding past myosin towards the M line, this brings the z line together without changing the length of actin or myosin

Question 22

What is needed to unbind actin and myosin

Answer 22

ATP

Question 23

What are type I muscle fibers?

Answer 23

slow twitch (oxidative)
weak sustained contraction (aerobic)
contains lots of myoglobin

Question 24

What are type IIa muscle fibers?

Answer 24

fast twitch (oxidative)
strong, fast contraction that cant be sustained

Question 25

What are type IIb muscle fibers

Answer 25

fast twitch (glycolytic) largest and most prevelant fast ATPase provides power and speed that cant be sustained for long anaerobic

Question 26

What are the components of a neuron?

Answer 26

cell body, axons, dendrites

Question 27

What are clumps of neurons called in the CNS vs the PNS

Answer 27

CNS is nuclei | PNS is ganglia

Question 28

What is a bipolar neuron?

Answer 28

one dendrite one axon

Question 29

What is a pseudounipolar neuron?

Answer 29

the weird weird one idk, just go look at a picture

Question 30

What is a multipolar neuron?

Answer 30

many dendrites and one axon

Question 31

What is the substance in the rER of neurons

Answer 31

Nissl substance

Question 32

What part sends signals? what part receives?

Answer 32

axons, dendrites

Question 33

What is the function of schwann cells?

Answer 33

myelinate PNS axons

Question 34

How does myelination speed up signal conduction?

Answer 34

creates nodes so the signal jumps from node to node

Question 35

What surrounds entire nerve fascicles?

Answer 35

epineurium

Question 36

What surrounds clusters of axons?

Answer 36

perioneurium

Question 37

What surrounds individual axons

Answer 37

endoneurium

Question 38

What is the function of a neuromuscular juntion

Answer 38

nerve innervating skeletal muscle by releasing ACh into the synaptic cleft

Question 39

What are the steps of the cellular mechanisms in the neuromuscular junction?

Answer 39

1. ACh released by axon 2. ACh stimulates change in sarcolemma that excites fiber and carried down T tubule 3. Enzymes break down ACh

Question 40

What problems can arise in the neuromuscular juntion?

Answer 40

probably a shit enzyme that isnt breaking down ACh, | myasthenia gravis where antibodies bind antagonistically to the ACh receptors

Question 41

What is the function of a muscle spindle receptor?

Answer 41

monitor change in length, rate of change, and tension in muscles

Question 42

What are intrafusal fibers?

Answer 42

specialized fibers inside a muscle spindle receptor

Question 43

What are nuclear bag fibers? What do they detect?

Answer 43

fibers wrapped by type Ia nerve fibers | -detect change in length/degree of tension

Question 44

WHat are nuclear chain fibers? what do they detect?

Answer 44

wrapped at their ends by type II nerve fibers | -detect static muscle strength.

Question 45

What are extrafusal fibers?

Answer 45

fibers outside the spindle (alpha motor fibers)