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Flashcards in Chapter 2 Deck (102):
1

Muscle strength is determined by?

1. Cross sectional area
2. Coordinated activation of muscle cells

2

What are Primary tissue types?

-muscle
-Nervous
-Connective
-Epithelial

3

types of muscles

Cardiac
Smooth
Skeletal

4

Where do you find smooth muscles ?

Arteries
Gut
Bladder

5

Skeletal Muscle is

Smooth or striated?

Striated

6

what is the name of the connective tissue surrounding Skeletal Muscles?

fascia or perimysium

7

What is the smallest compartment of skeletal muscle called ?

Fasciculus which contains a number of muscle fibers

8

Which heals faster ?

Tendon or muscle

Muscles

9

Muscle fibers are in what orientation to each other ?

parallel

10

Blood vessels location in a muscle

Blood vessels are wrapped in CT and are generally paralleled to fibers

11

Capillaries location in muscle

Run between fibers

12

Which type of contraction can limit blood flow?

Dynamic or Isometric

Isometric

13

What is the muscular NT

Acetylcholine

14

Muscle cell fibers contain

Nuclei
Mitochondria
Myoglobin
Myofibrills

15

Muscle color is due to

Myoglobin

16

Myoglobin is a

Respiratory Pigment

17

Myofibrils are surrounded by

Sarcoplasmic Reticulum

18

Smallest contractile unit of a muscle fiber

Sarcomere

19

Myofibril is a chain of

Sarcomeres laid end to end

20

The sarcomere has ------that keep contractile and regulatory proteins in the correct arrangement

Proteins

21

Muscle fiber filled with

Sarcoplasm

22

Striated appearance is due to

Cross banding of myofibrils

23

A band is

Dark

24

I band is

Light

25

Name proteins that are involved in force transmission to the enomysium

Actin
Alpha-actin
Vinculin
Talin
Dystrophin

26

Actomysin helps in

Muscle shortening

27

Mechanism of muscle contraction

Nerve impulse excitation, which releases calcium ( from SR) into the sarcoplasm and causes contraction of the filament array

28

Each thick filaments in the muscle fibers has ------myosin molecules

~200

29

Mechanism of contraction

Sarcomeres shorten
H zone disappears
Distance reduced between successive z lines
Filaments maintain their length ( do not shorten)
Thin filaments slide past thick, thus increasing their overlap

30

How many sarcomeres per cm of muscle fiber

~4000

31

Contraction speed depends on

1. Rate of myosin heads attaching, rotating and detaching
2. Muscle length

32

Slow isoform

Type I

33

Fast Isoform

Type II

34

Isometric force is related to

Sarcomere length

35

Force is inversely related to

velocity of shortening

36

What is a power stroke?

When activated myosin heads now bind to the actin as the myosin head changes shape to bent, which causes the head to pull on the thin filaments

37

ADP and P are released from

Myosin heads

38

What is a motor unit?

group of muscle fibers that are functionally united

39

Small motor units are for

Finely controlled muscles

40

Larger motor units are for

Coarse movement

41

Contraction force depends on

1. # of motor units simultaneously activated
2. Cross sectional area of the muscles

42

What is major difference in fiber types ?

speed of contraction

43

Slow twitch
Speed of contraction

Type I 80-100 ms

44

Fast Twitch
Speed of contraction

Type II
40 ms

45

Types of fibers

Type I ( red , Fatigue resistant)
II a ( red,Fatigue resistant )
II X ( White , fatiguable)

46

Does fiber type IIx have more contracting power or type I

Type IIx has 3X greater contracting power

47

Type IIx has more or fewer mitochondria ?

Fewer

48

Type IIx has more or less capillary supply?

Less or poorer

49

Type IIx has -----stores of glycogen and phosphocreatine

Larger

50

Type IIx fibers have

High activity of glycogenolytic and glycolytic enzymes

51

Type IIx fibers in terms of contraction?

Powerful contractions for brief periods

52

These kind of fibers have fast acting ATPases

II a and IIx

53

These kinds of fibers have oxidative capacity

IIa and type I

54

What type of neurons in type I fiber?

Small diameter
Slow conduction velocity
Low activation threshold

55

What type of neurons in Type II fibers

Large diameter
Fast conducting velocity
Higher activation threshold

56

Large motor units have what type of fibers

Fast

57

Small motor units have what type of fiber

Slow

58

Small/slow Motor units are used for

Posture/balance

59

Fast motor units are used for

Jumping/lifting/throwing/sprinting

60

In old age humans this type of fiber atrophy quicker

Type II

61

How does training affect the proportions of fiber types

Doesn't significantly affect it buy
Can affect the diameter specially type II

62

3 types of muscle contractions

-isometric
-Eccentric
-Concentric

63

High force eccentric contraction is also called

Delayed onset muscle soreness

64

Reasons for DOMS

Small # of fibers activated
Type II fibers may be selectively recruited ?
High load on few fibers--> ruptures of the fibers

65

Skeletal muscle adaptability to strength training

Hypertrophic response
(Muscle gets bigger )

66

Hypertrophic responses cause

Greater power
Greater anaerobic capacity

67

Gradual hypertrophy occurs because of

Increased fiber diameter NOT increased fiber number

68

Does proportion of different fiber types change in hypertrophy?

NOOOOO

69

The -----content of tissues give them their shape

Protein

70

Enzyme content determines

Function

71

Amount of enzyme determines

Speed of enzyme process

72

Side chains give proteins their

Special structure @ physiological pH

73

Most abundant AA in muscles

Branched-chain AA
20%

74

What is the most abundant free AA in muscle and plasma

Glutamine

75

Protein structure classification

Primary
Secondary
Tertiary- 3D shape
Quaternery

76

Major protein storage in body

No major storage other than skeletal muscle

77

What happens to excess protein

Excess protein is oxidized and N excreted

78

Strength training induce anabolism or catabolism

Anabolism

79

Does endurance training induce anabolism

NO

80

3 main purpose of protein breakdown

-Degrades damaged proteins
-Provides energy
-AAs can be reused for synthesis of proteins and non proteins like glucose, ketones and fat

81

Well trained athletes have ---- post exercise turn over

Less or More?

Less

82

Anabolic hormones

Growth hormone
Insulin
Testosterone
Triiodothyronine
Glucagon

83

This hormone antagonizes actions of insulin

Growth hormone

84

This hormone induces liver to release somatomedins

Growth hormone

85

Growth hormone is most effective in stimulating

Collagen synthesis (CT)

86

This hormone causes growth in bones of face, hands, feet & predisposition to diabetes

Growth hormone

87

Growth hormone is not optimally effective for

Muscle growth

88

Insulin stimulates -----synthesis

Protein

89

Health risk of testosterone

Cardiovascular dz
Liver cancer

90

Unit of enzyme activity measurement

International Unit: IU

91

What is IU:

The amount of enzyme to convert one micromole of substrate to product in one minute under specified conditions

92

SI unit for IU

Katal (Kat)

93

What is 1kat

The amount of enzyme that will convert 1 mole of substrate to product in 1 sec ( in optimum conditions )

94

Optimal temp for enzyme activity

25-37

95

Warmer muscles have higher

Reaction rates thus better muscle performance

96

What metal ions are essential for enzyme activation

Ca
Mg
Zn

97

Allosteric Modulation

Reversible binding of small molecules to the enzyme at sites other than active sites-producing a conformation change in the structure of the enzyme molecule.

98

Risks of taking more than needed protein >3g/day

Kidney damage

Increased serum lipoprotein levels (arteriosclerosis risk)

Dehydration

99

95% of creatine in the body is in

Skeletal muscle
2/3 is phosphocreatine

100

Liver and kidney can synthesize creatine from

Methionine
Arginine
Glycine

101

Risks of consuming testosterone

Decrease in HDL
Acne
Inappropriate hair growth
Prostate enlargement
Poor testicular function
Liver damage

102

Other performance enhancing drugs

Caffeine
Ephedrine
Pseudoephedrine
Beta agonist---stimulate effects of catecholamine hormones . Fight or flight