Muscle Phys II

Question 1

How does the phosphagen system work and how much energy does it provide

Answer 1

Uses creatine phosphate to regenerate atp quick (direct phosphorylation (provides energy for the first 8-10 sec)

Question 2

Anaerobic glycolosis- what is created and how long does it provide energy for

Answer 2

Pyruvate converted to lactic acid due to lack of O2

-Provides energy for about 30-60 sec of exertion

Question 3

Oxidative phosphoylation- how much atp does it produce

Answer 3

95% of atp during rest and light-mod activity

Question 4

ETC- how much atp does it produce and what is required for it to work

Answer 4

90% of the ATP used by the body for functions

Requires vit B2, iron, copper

Question 5

What is oxygen debt used for (3)

Answer 5

1. replenishing o2 resevers
2. Help get rid of lactic acid
3. Used in ox phosphorylation to produce atp (by converting creatine to creatine phosphate, amp to atp)

Question 6

Type 1/slow oxidative- myoglobin content, capillary count, mito count, glycogen stores

Answer 6

myoglobin content, high
capillary count, high
mito count, high
glycogen stores, low

Question 7

Type IIa/ Fast oxidative- myoglobin content, capillary count, mito count, glycogen stores

Answer 7

myoglobin content, high
capillary count, high
mito count, high
glycogen stores, medium

Question 8

Type IIb/ Fast glycolitic- myoglobin content, capillary count, mito count, glycogen stores

Answer 8

myoglobin content, Low
capillary count, Low
mito count, Low
glycogen stores, High

Question 9

What is the avg mm distribution of mm fibres

Answer 9

55-65% type 1
30-35 type IIa
15% type IIb

Question 10

What are some mm adaptations to endurance training

Answer 10

more myoglobin, mito
angiogenesis
smaller mm fibres (smaller distance for o2 and glucose to diffuse

Question 11

What are some mm adaptations to power training

Answer 11

hypertrophy of type II

increase in muscle length + # of sarcomeres

Question 12

What mm fibres can change in more endurace training

Answer 12

fast cant change to slow but.

can result in a shift of type IIb to IIa

Question 13

What are the 3 types of motor units

Answer 13

S- slow
FR- fast, resistent to fatigue
FF- fast, fatiguable

Question 14

what types of mm have small and large motor units

Answer 14

mm that control fine movements have small mm units (for better control, low threshold)

mm that control large mvmts have large mm units (higher threshold)

Question 15

How does recruitment of mm units occur

Answer 15

smaller fibres will be recruited first and as the strength of the signal increases the progressivel larger fibres will be recruited

Question 16

what does a simple twitch result in

Answer 16

Result of a single stim of a mm, leading to contraction of all fibres in a motor unit (response to a single threshold stim)

Question 17

what is a incomplete tetnus due to

Answer 17

the result of multiple stim leading to a repeated wave of summations

Question 18

What is fused/complete tetnus (how much stronger is it than a simple twitch)

Answer 18

a sustained and smooth max contraction in which multiple stim occur close in time
(3-4x stronger than a simple twitch)

Question 19

What is the Frank Starling Law

Answer 19

Strength of mm contraction that is directly proprotionate t the initial length of the mm

Question 20

What is L-max

Answer 20

the optimal sarcomere length where max number of cross bridges are formed

Question 21

Why does muscular fatigue occur (5)

Answer 21

1. Depletion of energy stores
2. Lack of o2 leading to atp deficit
3. Accumulation of lactic acid (inhibits enzymes)
4. Accumulation of K in the ECF (disturbed excitability)
5. ROS (decreased Ca sensitivity)

Question 22

Why does neuromuscular fatigue occur + why

Answer 22

due to increased release of Ach at NMJ

-this type of fatigue occurs during fast/powerful activities

Question 23

Why does central fatigue occur + why (2)

Answer 23

When the CNS no longer adequetly activates the motor neurons supplying mm

-Hypoglycemia + acidosis (from lactic build up)