Chapter 3 - Muscle Structure And Function Flashcards Preview

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Flashcards in Chapter 3 - Muscle Structure And Function Deck (81):
0

Human body consists of _____ muscles

640

1

Muscle makes up ___-___% (in women) and ___-___ (in men) of body mass

30-35 in women and 42-47 in men

2

What are the 3 basic types of muscle?

1) skeletal
2) smooth
3) cardiac

3

What is another name for skeletal muscle?

Striated muscle

4

Skeletal muscle connects the various parts of the skeleton through one or more connective tissue structures called _______

Tendons

5

During muscle _______ skeletal muscle shortens and moves various parts of the skeleton

Contraction

6

How can the required smoothness and speed of muscles be achieved?

Through the graded activation of muscles

7

Are skeletal muscles under voluntary or involuntary control?

Under voluntary control

8

________ involves the assessment of movement and the sequential pattern of muscle activation that that move body segments

Biomechanics

9

What is most skeletal muscle attached to?

Bone

10

What is skeletal muscles contraction responsible for?

Supporting and Moving the skeleton

11

List 4 spots u can find smooth muscle.

1) blood vessels
2) respiratory tract
3) iris of the eye
4) gastro-intestinal tract

12

Are the contractions of smooth muscle slow and uniform?

Yes

13

What are the functions of the smooth muscle?

To alter the activity of various body parts to meet the needs f the body at that time

14

Smooth muscle is fatigue _______

Resistant

15

Activation of smooth muscle is ________

Involuntary

16

Swallowing food in the esophagus uses wave like movements called _____

Peristalsis

17

What kind of muscle has characteristics of both skeletal and smooth

Cardiac muscle

18

What are the functions of cardiac muscle

To provide the contractile activity of the heart

19

Contractile activity can be ______ (like skeletal muscle)

Graded

20

Is very fatigue _______

Resistant

21

Activation of cardiac muscle is ________ (like smooth muscle)

Involuntary

22

What are the 4 components of skeletal muscle?

1) muscle belly
2) muscle fiber bundle
3) muscle fiber
4) filament proteins

23

What is the muscle belly? (Of skeletal muscle)

The "whole" of the muscle is the muscle belly

24

What is the muscle fiber bundle? (Of skeletal muscle)

Muscle fiber bundle is a bunch of fibers bundled together

25

What are muscle fibers? (Skeletal muscle)

Muscle fibers are the individual muscle fibers that make up the bundle

26

Where are filament proteins found in skeletal muscle?

Inside the myofibril

27

Muscle fibers are ______ shaped cells that make up the skeletal muscle

Cylinder

28

Each muscle fiber is made up of a nber of _________

Myofilaments

29

Muscle fibers are surrounded by a connective tissue sheath (membrane) called __________

Sarcolemma

30

Many muscle fibers are enclosed by connective tissue sheath called _______ to form a bundle of fibers

Perimysium

31

What 2 things does each muscle fiber contain?

1) contractile machinery
2) cell organelles

32

Muscle fibers are activated through nerve impulses via ____ ____ ____

Motor end plate

33

What is a group of muscle fibers activated via the same nerve called?

Motor unit

34

Each muscle fiber has _______ that supply nutrients and eliminate waste

Capillaries

35

What is the agonist (prime mover)?

The muscle or group of muscles producing a desired effect
Eg. The bicep when lifting an object

36

What is the antagonist?

The muscle or group of muscles opposing the action
Eg. The triceps relax when the bicep is working

37

What is the synergist?

The muscles surrounding the joint being moved

38

What are the fixators?

The muscle of group of muscles that steady joints closer to the body axis so that the desired action can occur

Muscles that stabilize so you don't dislocate

Eg. If you are carrying 45 pounds of weight in your hand your shoulder would pop out if not for the shoulder fixator muscles

39

Sarcomeres are ________ units

Contractile

40

What are the 2 types of protein myofilaments in sarcomeres?

Actin
Myosin

41

What are actin

Thin filament

42

What are myosin

Thick filament

43

Each myosin is surrounded by ___ actin filaments

6

44

Projecting from each myosin are tiny contractile _______ _______.

Myosin bridges

45

What is cross bridge formation?

- a signal comes from the motor nerve activating the fiber

-the heads of the myosin filaments temporarily attach themselves to the actin filaments

- active action coming from the brain
Motor nerve activates fiber causing the myosin to attach to actin

46

What is cross bridge movement?

- similar to the stroking of the para and movement of rowing shell

- movement of myosin filaments in relationn to actin filaments

- shortening of the sarcomere

- shortening of each sarcomere is additive

47

Sarcomeres should be _____ distance apart

Optimal

48

What happens if the sarcomeres are stretched farther apart than optimal distance?

Then fewer cross bridges can form which means less force is produced

49

What happens if the sarcomeres are too close together?

Cross bridges then interfere with one another as they form which means less force is produced

50

Maximal force occurs at what 2 things?

Optimal muscle length and joint angle

51

Optimal joint angle occurs at ______ ______ ______

Optimal muscle length

52

The distance between sarcomeres needs to be optimal for what to occur

Maximum exertion of force

53

What are the 2 types of muscle fibers?

Slow twitch fibers and fast twitch fibers

54

Slow twitch fibers

- slow oxidative (type 1)
- continuous repition but slowly
- suited for repeated contractions during activities requiring a force output of less than 20-25% of max force output
- examples: lower power activities, endurance events
- have less capacity to generate force

55

Fast twitch fibers

- fast glycolytic (type lla)
- fast oxidative glycolytic (type llb)
- explosive fibers
- for maximum utilization
- significantly greater force and speed generating capability than slow twitch fibers
- well suited for activities involving high power, low endurance
- examples: sprinting, jumping, throwing
- you want explosiveness

56

Give a comparison example between fast twitch and slow twitch

Jumping on the spot would be slow twitch while jumping distance would be fast twitch

57

Nervous system can be divided into what 2 parts?

Central nervous system (CNS)
Peripheral nervous system (PNS)

58

What 2 functions can the nervous system be divided into?

Motor and sensory activity

59

Sensory

Collects info from the various sensors located throughout he body and transmits the info to the brain

60

Motor

Conducts signals to activate muscle contraction

61

Most f what happens in our eyes is _______

Sensory

62

Hot receptors cold receptors pressure receptors are all examples of ______

Sensory

63

Motor nerves extend from where to where

From the spinal cord to the muscle fibers

64

How is each muscle fiber activated by motor nerves?

Through impulses delivered via the motor end plate

65

Motor unit

A group of fibers activated via the same nerve

66

True or false: all muscle fibers of one particular motor unit are always of the same fiber type

True

67

What do muscles that need to perform precise movements generally consist of?

A large number of motor units and new muscle fibers

68

What do muscles who need to perform less precise movements generally consist of?

Fewer motor units with many fibers per unit

69

All or none principle

Whether or not a motor unit activates upon the arrival of an impulse depends upon the so called all or none principle

70

What is required to cause the inner cared fibers to contract?

An impulse of a certain magnitude (or strength)

71

Every motor unit has a special _______ that much be reached for such activation to occur

Threshold

72

What is intra muscle coordination

The capacity to apply motor units simultaneously

73

How much of their available muscle fibers can highly trained power athletes (weightlifters, wrestlers and shot putters) activate up to? Vs an untrained person?

85% vs 65%

74

Force deficit

The difference between assisted and voluntarily generated maximal force

75

Inter muscle coordination

The interplay between muscles that generate movement through contraction (agonists) and muscles responsible for opposing movements (antagonists)

76

The greater the participation of muscles and muscle groups the higher the what?

The higher the importance of inter muscle coordination

77

Prime mover is controlled by ______

Antagonist

78

The greater the participation, the greater the _________

Functionality

79

Individuals performance improvements occur through a process of _________ _________ which is reflected on the body's increased strength

Biological adaptation

80

What does adaptation of muscles depend on?

Intensity levels used in training and on athletes uniqr biological makeup