Chapter 8

Question 1

Draw and label the microstructure of a skeletal muscle fiber.

Question 2

Define satellite cells. What role do satellite cells play in muscle repair from injury?

Question 3

List and explain the chain of events that occur during muscular contraction.

Question 4

Define both dynamic and static exercise. What types of muscle action occur during each form of exercise?

Answer 4

dynamic - muscle action:contractic, eccentric
muscle length change: decreae or increase

static - isometic mucsle action
muscle length change: no change

Question 5

Describe the factors that determine the amount of force produced during muscular contraction.

Answer 5

1) types and number of motor units recruited
2) the intial muscle length
3) the nature of the motor units nerual stimulation
4) prior contractile activity of the muscle

Question 6

Compare and contrast the major biochemical and mechanical properties of the three primary types of muscle fibers found in human skeletal muscle.

Question 7

concentric action

Question 8

extensors

Answer 8

muscles that increase joint angles

Question 8

Describe how skeletal muscle fiber types influence athletic performance.

Question 9

dynamic

Question 9

Graph and describe the relationship between movement velocity and the amount of force exerted during muscular contraction.

Question 10

actin

Answer 10

located in myofibrils

Question 11

eccentric action

Question 12

endomysium

Answer 12

each muscle fibre within the fascicles is surrounds by connected tissue called endomysium

Question 13

end-plate potential EPP

Question 13

epimysium

Answer 13

outer layer of the entire muscle

Question 14

fascicle

Answer 14

individual bundles of muscle fibers

Question 15

fast-twitch fibres

Question 16

flexors

Answer 16

muscles that decrease joint angles

Question 17

intermediate fibers

Question 18

isometric action

Question 19

lateral sac

Question 20

motor neurons

Question 21

motor unit

Question 22

muscle action

Question 23

myosin

Answer 23

located in myofibrils

Question 24

neuromuscular junction (NMJ)

Question 25

perimysium

Answer 25

surrounds individual bundles of muscle fibers

Question 26

post activation potential PAP

Answer 26

increase in muscle force production that occurs following a bout of non-fatiguing submaximal muscle construction (warm up)

Question 27

sarcolemma

Answer 27

cell membrane surrounding the muscle fibre

Question 28

sarcomeres

Question 29

sarcoplasmic reticulum

Answer 29

storage sites for calcium - calcium is required to trigger contractions

Question 30

sliding filament model

Question 31

slow-twitch fibres

Question 32

summation

Question 33

wining lever-arm model

Question 34

terminal cisternae

Question 35

tetanus

Question 36

transverse tubules

Question 37

topomysoin

Answer 37

protein located on actin molecules play role in regulation of contractility with tropic

Question 38

tropin

Answer 38

protein located on actin molecule - play role in regulation of contractility with topomysoin

Question 39

twice

Question 40

type 1 fibers

Question 41

type II fibers

Question 42

type II x fibers

Question 43

Describe the principal functions of skeletal muscles.

Question 44

List the principal contractile proteins contained in skeletal muscle.

Question 45

Outline the contractile process. Use a step-by-step format illustrating the entire process, beginning with the nerve impulse reaching the neuromuscular junction.

Question 46

Define muscle fatigue. Discuss those factors that contribute to skeletal muscle fatigue during exercise lasting: (1) 1–10 minutes and (2) >60 minutes.

Question 47

Define the term muscle cramp. Discuss the two leading hypotheses to explain the cause of exercise-induced muscle cramps.

Question 48

Describe the mechanical and biochemical properties of human skeletal muscle fiber types.

Question 49

Discuss those factors thought to be responsible for regulating force during muscular contractions.

Question 50

Define the term summation.

Question 51

Graph a simple muscle twitch and a contraction that results in tetanus.

Question 52

Discuss the relationship between force and speed of movement during a muscular contraction

Question 53

what are the adaptations training causes on NMJ

Answer 53

increase NMJ size - enhance synaptic vesicle storage (ach) - increase the sensitivity of Ach on the post synaptic membrane

Question 54

what causes muscle cramps

Answer 54

1) dehydration does to cause cramps 2) CNS due to excitable motor neuron-->

Question 55

biochemical properties of muscle

Answer 55

oxidative capacity (number of capillaries, mitochondria, and amount of myoglobin) type of myosin ATPase isofrom - speed of ATP deviation abundance of contractile protein in the muscle fibre - actin and myosin

Question 56

contractile properties of skeletal muscle

Answer 56

maximal force production speed of contraction (Max) maximal power output = force x shortening velocity muscle fiber efficiency

Question 57

compare the three types of muscle fibers

Answer 57

type I type ii -a type ii -x

Question 58

fill out the characteristics for each fibre type - number of mitochondira resistance to fatigue predominant engird system ATpase activity Max (speed shortening) efficiency specific tension

Answer 58

see chart