Muscle

Question 1

_____ contain sarcomeres

Answer 1

Myofibrils

Question 2

_____ is a bundle of myofibrils

Answer 2

Muscle cell/fiber

Question 3

Endomysium surrounds?

Answer 3

Muscle fiber

Question 4

____ is a bundle of muscle fibers

Answer 4

Muscle fasciculus

Question 5

Perimysium surrounds?

Answer 5

Muscle fasciuli

Question 6

Epimysium surrounds?

Answer 6

Whole muscle

Question 7

__% of nerve fibers are efferent and __% are afferent

Answer 7

60% efferent, 40% afferent

Question 8

Efferent nerve fibers in muscle are called?

Answer 8

Alpha motor neurons

Question 9

Role of alpha motor neurons

Answer 9

Carry info into muscle

Question 10

Afferent nerve fibers are associated with?

Answer 10

1. Mechanoreceptors

2. Chemoreceptors

Question 11

A triad is made of?

Answer 11

Cisternae + t-tubule + cisternae

Question 12

Cisternae is associated with?

Answer 12

Calcium release

Question 13

Cisternae is located between?

Answer 13

Longitudinal or light SR

Question 14

What is calsequestrin?

Answer 14

Binding protein which reduces gradient

Question 15

Calsequestrin plays a role in?

Answer 15

Ca reuptake

Question 16

What is DHP?

Answer 16

T-tubule protein similar to voltage-sensitive Ca channel

Question 17

What is ryanodine?

Answer 17

Functional Ca release channel

Question 18

Sarcomere is defined from?

Answer 18

Z line to Z line

Question 19

H zone during contraction

Answer 19

Gets smaller

Question 20

I band during contraction

Answer 20

Gets smaller

Question 21

Actin are _____ filaments

Answer 21

Thin

Question 22

Myosin are _____ filaments

Answer 22

Thick

Question 23

Which filaments make up A band?

Answer 23

Myosin

Question 24

A band during contraction

Answer 24

Does not change length

Question 25

What is the A band?

Answer 25

Length of the myosin

Question 26

What is the H zone?

Answer 26

Length between actin filaments

Question 27

What is the I band?

Answer 27

Distance between 2 discrete myosin filaments

Question 28

2 types of myosin

Answer 28

1. Light meromyosin | 2. Heavy meromyosin

Question 29

Hinge region is located between?

Answer 29

Light and heavy meromyosin

Question 30

Hing region is active in?

Answer 30

Coupling chemical to mechanical energy

Question 31

Myosin ATPase is located on?

Answer 31

Myosin head

Question 32

2 isoenzymes of myosin ATPase

Answer 32

1. Fast | 2. Slow

Question 33

Fast twitch fibers are used for?

Answer 33

Locomotion

Question 34

Slow twitch fibers are used for?

Answer 34

Posture

Question 35

2 enzymes located in M-line

Answer 35

1. Creatine phosphokinase (CPK) | 2. Myokinase

Question 36

CPK catalyzes what reaction?

Answer 36

ADP + CrP → ATP + Cr

Question 37

Myokinase catalyzes what reaction?

Answer 37

ADP + ADP → ATP + AMP

Question 38

Tropomyosin plays what type of role?

Answer 38

Regulatory

Question 39

2 proteins on actin

Answer 39

1. Tropomyosin | 2. Troponin

Question 40

Major protein of Z-line

Answer 40

Alpha-actinin

Question 41

3 types of troponin

Answer 41

1. TN-I 2. TN-C 3. TN-T

Question 42

TN-I function

Answer 42

Inhibits active binding site

Question 43

TN-C function

Answer 43

Contains Ca binding site

Question 44

TN-T function

Answer 44

Binds to tropomyosin

Question 45

Z-line during contraction

Answer 45

Gets shorter

Question 46

l(0) is?

Answer 46

Optimal length (Z-line to Z-line)

Question 47

Ideal l(0)

Answer 47

2.0-2.2 um

Question 48

1 myosin filament interacts with ___ actin filaments

Answer 48

6

Question 49

Titin function

Answer 49

Acts like anchor/spring to keep myosin filaments in place

Question 50

Nebulin function

Answer 50

Molecular ruler in assembly of actin

Question 51

Dystrophin function

Answer 51

Anchors contractile proteins to cellular membrane

Question 52

alpha-actinin function

Answer 52

Located in Z-line and connects actin filaments together

Question 53

Motor unit

Answer 53

Innervates one or more m. fibers

Question 54

All m. fibers connected to motor unit have same?

Answer 54

Contractile and metabolic properties

Question 55

Synaptic cleft is how wide?

Answer 55

50 nm

Question 56

Acetylcholinesterase functions

Answer 56

Cleaves Ach for reuptake into presynaptic cell

Question 57

When Ach binds to motor end plate, what happens?

Answer 57

1. Na+ influx via gated ion chanel 2. Depolarization (end plate potential) 3. EEP comes out of cleft → starts AP across cell membrane

Question 58

Chemoreceptors are Group ___

Answer 58

Group IV

Question 59

Chemoreceptors sense?

Answer 59

[H+], K+, Pi

Question 60

3 types of mechanoreceptors

Answer 60

1. Muscle spindles 2. Golgi tendon organs 3. Group III

Question 61

I(a) fibers aka?

Answer 61

Muscle spindles

Question 62

I(b) fibers aka?

Answer 62

Golgi tendon organs

Question 63

Group III fiber myelination

Answer 63

Thinly myelinated

Question 64

GTO activation

Answer 64

Inhibits alpha-motor neuron output

Question 65

Muscle spindles run parallel with?

Answer 65

Extrafusal fibers

Question 66

Primary annulospiral ending function

Answer 66

Quick responders to changes in muscle length (dynamic)

Question 67

Secondary flower-spray ending function

Answer 67

Tonic input to m. length (static)

Question 68

Gamma efferents stimulate intrafiusal fibers to?

Answer 68

Contract

Question 69

Alpha-motor neuron stimulates intrafusal fibers to/

Answer 69

Contract