TOPIC 9 - SKELETAL SYSTEM - frequency of stimulation

Question 1

muscle tension in a fibre, affected by: frequency of stimulation

what does a single stimulus produce?

Answer 1

produces a twitch (not normally occurring in skeletal muscles)

Question 2

Psychological Fatigue

Answer 2

failure of CNS to send commands to muscles

Question 3

psychological fatigue

failure of CNS to send commands to where? - probably due to what?

Answer 3

to muscles

probably due to lactic acid

Question 4

muscles and EPOC

what does EPOC stand for?

Answer 4

excess post-exercise 0₂ consumption

Question 5

Muscles and EPOC

O₂ used to:

1. replenish what?
2. convert what to what?
3. increase in _______ ________ from what? - which increases what?

Answer 5

1. replenish stores of glycogen, C, P, 0₂ on hb/myoglobin
2. convert lactic acid to:
   
   • pyruvic acid ⇒ Krebs
   • glucose in liver
3. also increase in body temperature from exercise = increases O₂ demand (faster chemical reactions)

Question 6

Physiological fatigue

inability to?

Answer 6

maintain tension

Question 7

physiological fatigue

what does it decrease?

Answer 7

ATP use

therefore, protective (if too little, crossbridges can’t release)

Question 8

physiological fatigue

decreases ATP use, therefore protective

if too little…what happens

Answer 8

crossbridges can’t release

Question 9

physiological fatigue is due to?

1. depletion of?
2. build-up of?
3. failure of?

Answer 9

1. depletion of energy supplies e.g. glycogen
2. build up of end products
3. failure of APs

Question 10

muscle metabolism

energy for _________

Answer 10

contraction

Question 11

muscle metabolism

energy for contraction during resting conditions

• fatty acids used to produce what?
• storage of?

Answer 11

• fatty acids used to produce ATP (aerobic)
• storage of:
  
  • glycogen
  • creatine Phosphate
  • little atp

Question 12

muscle metabolism

energy for contraction during short term exercise (less than 1 minute)

• primarily ________
• uses what?
• what is used to produce what? how long does it last for?
• muscle glycogen ⇒ _________ ⇒ pyruvic acid ⇒ ___________ ______ ⇒ lactic acid
  
  • lasts for how long?

Answer 12

• primarily anaerobic
• use available atp
• creatine phosphate used to produce atp - lasts ~15 seconds
• muscle glycogen ⇒ glucose ⇒ pyruvic acid ⇒ anaerobic pathway ⇒ lactic acid
  
  • lasts for ~30 seconds

Question 13

muscle metabolism

energy for contraction during short term exercise (less than 1 minute)

no hints

Answer 13

• primarily anaerobic
• use available atp
• creatine phosphate used to produce atp - lasts ~15 seconds
• muscle glycogen ⇒ glucose ⇒ pyruvic acid ⇒ anaerobic pathway ⇒ lactic acid
  
  • lasts for ~30 seconds

Question 14

muscle metabolism

energy for contraction for long term exercise (1 minute to hours)

• _____ - from ______ pathway
• _______ (from liver)
• fatty acids - ______ more as what continues?
• O₂ sources: blood hemoglobin + _______ _______
• but sometimes _____________

Answer 14

• ATP - from aerobic pathway
• glucose (from liver)
• fatty acids - used more as exercise continues
• O₂ sources: blood hemoglobin + muscle myoglobin
• but sometimes anaerobic

Question 15

muscle metabolism

energy for contraction for long term exercise (1 minute to hours)

no hints

Answer 15

• ATP - from aerobic pathway
• glucose (from liver)
• fatty acids - used more as exercise continues
• O2 sources: blood hemoglobin + muscle myoglobin
• but sometimes anaerobic

Question 16

muscle metabolism

energy for contraction during resting conditions

Answer 16

• fatty acids used to produce ATP (aerobic)
• storage of:
  
  • glycogen
  • creatine Phosphate
  • little atp