muscles 4

Question 1

What two things is muscle performance considered in terms of?

Answer 1

Force and Endurance

Question 2

muscle performance and force

Answer 2

• power, strength

- max alt of tension produced by a muscle or muscle group

Question 3

endurance and muscle performance

Answer 3

amt of time during which an indiv. can performa particular activity

Question 4

Factors that determine performance capabilities of a skeletal muscle

Answer 4

• types of muscle fiber present in the muscle

- physical conditioning or training

Question 5

Type I fibers

Answer 5

• slow fibers

- slow twitch oxidative fivers

Question 6

Type II-A fibers

Answer 6

• intermediate fibers
• fast twitch oxidative fibers
• fast fibers w/ greater endurance capability

Question 7

Type II-B

Answer 7

• fast fibers
• fast twitch glycolytic fibers
• greater capacity for anaerobic metabolism

Question 8

slow fibers (red)

Answer 8

• half the diameter of fast fibers
• take 3x as long to contract after stimulation
• abundant mitochondria
• extensive capillary supply
• high concentrations of myoglobin
• can contract for long periods of time

Question 9

what does abundant mitochondria do in slow fibers?

Answer 9

allows aerobic respiration, oxidative metabolism

Question 10

what does high concentrations of myoglobin do in slow fibers

Answer 10

-greater oxygen reserve and oxygen diffusion, more readily available

Question 11

fast fibers (white)

Answer 11

• large in diameter
• contain densely packed myofibrils
• large glycogen reserves
• relatively few mitochondria
• produce rapid, powerful contractions of short duration
• fatigue rapidly

Question 12

what do small amounts of mitochondria do in a fast fiber?

Answer 12

causes anaerobic, glycolytic metabolism

Question 13

intermediate fibers

Answer 13

• fast fibers that gain greater resistance to fatigue
• additional capillary supply
• more mitochondria
• smaller diameter
• not as dependent on anaerobic metabolism
• can be trained

Question 14

How is the percentage of slow and fast fibers determined?

Answer 14

genetically and can vary considerably among muscles

Question 15

Which fibers can change due to training?

Answer 15

fast with intermediate properties

Question 16

hypertrophy

Answer 16

increase in diameter of muscle with use

Question 17

atrophy

Answer 17

decrease in diameter of muscle

Question 18

does the number of muscle fibers change under normal conditions?

Answer 18

no, we don’t produce new muscle cells

Question 19

why does change in diameter of muscles change?

Answer 19

• increase or decrease depending on level of activity over time
• increased activity leads to synthesis of more actin and myosin myofilaments
• decreased activity leads to loss of actin and myosin filaments

Question 20

what does long term disuse of muscles lead to?

Answer 20

irreversible atrophy in muscle if muscle cells die

Question 21

physical conditioning, anaerobic endurance

Answer 21

time period in which muscular contractions are sustained by glycolysis after depleting ATP/CP

Question 22

physical conditioning, aerobic endurance

Answer 22

time period in which muscle can continue to contract while supported by activities after depleting ATP/CP reserves

Question 23

physical conditioning, improve anaerobic endurance

Answer 23

• frequent brief, intensive workouts
• increase muscle mass
• ATP/CP reserves
• glycogen reserves
• ability to tolerate lactic acid buildup

Question 24

physical conditioning improve aerobic endurance

Answer 24

sustained low levels of activity

• increase bloody supply to muscles
• improve cardiovascular activity

Question 25

What happens to muscles with age?

Answer 25

- decrease in size, strength and endurance of muscles - skeletal muscle becomes less elastic - tolerance for exercise decreases - ability to recover from muscular injuries decreases

Question 26

why do muscles decrease in size and strength with age?

Answer 26

- reduction in size decreases the number of myofibrils | - decrease in endurance due to less ATP, CP, glycogen, and myoglobin

Question 27

Why does skeletal muscle become less elastic with age?

Answer 27

develop increasing amounts of fibrous connective tissue (fibrosis)

Question 28

Why does tolerance for exercise decrease with age?

Answer 28

- Muscles fatigue more quickly | - reduction in thermoregulatory ability, thus are subject to over heating

Question 29

Why does the ability to recover from injuries decrease with age?

Answer 29

- number of satellite cells decreases with age | - repair capabilities become more limited, more scar tissue (fibrous tissue) formation occurs

Question 30

Primary muscle disorders

Answer 30

result from problems with the muscular system itself - muscle trauma - muscle infections - inherited disorders - tumors

Question 31

Secondary disorders

Answer 31

result in problems originating in - nervous system disorders - nutritional or metabolic problems - cardiovascular disorders

Question 32

Muscular system disorders

Answer 32

1) muscle spasm 2) muscle spasticity 3) muscle flaccidity 4) muscle atrophy 5) myositis 6) strain 7) paralysis

Question 33

muscle spasm

Answer 33

(cramp) strong sudden usually painful, unwanted contraction

Question 34

muscle spasticity

Answer 34

excessive muscle tone

Question 35

muscle flaccidity

Answer 35

very low muscle tone

Question 36

muscle atrophy

Answer 36

deterioration or wasting due to disuse, immobility, or interference with normal motor neuron innervation

Question 37

myositis

Answer 37

muscle inflammation | -polymyositis and dermatomyositis= autoimmune

Question 38

strain

Answer 38

tears in muscle tissue | -sparin tears in ligament or tendon or joint capsule

Question 39

paralysis

Answer 39

loss of voluntary motor control | -flaccid or spastic

Question 40

nervous system disorders that affect the coordination or control of muscle contraction

Answer 40

- blockage of release of ACh (botulism - Interference with binding of ACh to receptors - Interference with AChE activity - loss of motor neuron (polio) - loss of motor neuron axon-peripheral nerve damage - excessive stimulation of motor neuron (e.g. tetanus)

Question 41

flaccid paralysis examples

Answer 41

- blockage of release of ACh (botulism - Interference with binding of ACh to receptors - loss of motor neuron (polio) - loss of motor neuron axon-peripheral nerve damage

Question 42

spastic paralysis examples

Answer 42

-Interference with AChE activity | excessive stimulation of motor neuron (e.g. tetanus)

Question 43

inherited muscular disorders

Answer 43

- Muscular dystrophies | - myotonic dystrophy

Question 44

muscular dystrophies

Answer 44

muscle structure is compromised, problem with how muscle proteins are structured - duchennes MD - early onset

Question 45

myotonic dystrophy

Answer 45

chromosome 19 disorder | -typically onset is after puberty

Question 46

Muscle trauma

Answer 46

- minor trauma - major trauma - new muscle cel production from satellite cells-limited ability - scar tissue formation - compartment syndrome

Question 47

minor muscle trauma

Answer 47

damage to myofibrils, sarcolemma from excessive activity

Question 48

major muscle trauma

Answer 48

laceration, crushing, deep bruise, muscle tear (strain)