Chapter 2 Flashcards
(102 cards)
1
Q
Muscle strength is determined by?
A
- Cross sectional area
2. Coordinated activation of muscle cells
2
Q
What are Primary tissue types?
A
- muscle
- Nervous
- Connective
- Epithelial
3
Q
types of muscles
A
Cardiac
Smooth
Skeletal
4
Q
Where do you find smooth muscles ?
A
Arteries
Gut
Bladder
5
Q
Skeletal Muscle is
Smooth or striated?
A
Striated
6
Q
what is the name of the connective tissue surrounding Skeletal Muscles?
A
fascia or perimysium
7
Q
What is the smallest compartment of skeletal muscle called ?
A
Fasciculus which contains a number of muscle fibers
8
Q
Which heals faster ?
Tendon or muscle
A
Muscles
9
Q
Muscle fibers are in what orientation to each other ?
A
parallel
10
Q
Blood vessels location in a muscle
A
Blood vessels are wrapped in CT and are generally paralleled to fibers
11
Q
Capillaries location in muscle
A
Run between fibers
12
Q
Which type of contraction can limit blood flow?
Dynamic or Isometric
A
Isometric
13
Q
What is the muscular NT
A
Acetylcholine
14
Q
Muscle cell fibers contain
A
Nuclei
Mitochondria
Myoglobin
Myofibrills
15
Q
Muscle color is due to
A
Myoglobin
16
Q
Myoglobin is a
A
Respiratory Pigment
17
Q
Myofibrils are surrounded by
A
Sarcoplasmic Reticulum
18
Q
Smallest contractile unit of a muscle fiber
A
Sarcomere
19
Q
Myofibril is a chain of
A
Sarcomeres laid end to end
20
Q
The sarcomere has ——that keep contractile and regulatory proteins in the correct arrangement
A
Proteins
21
Q
Muscle fiber filled with
A
Sarcoplasm
22
Q
Striated appearance is due to
A
Cross banding of myofibrils
23
Q
A band is
A
Dark
24
Q
I band is
A
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
