Lecture 26: Skeletal Muscle Energy, Types, and Function

Question 1

Energy sources for contraction include:

Answer 1

• ATP
• CP
• Anaerobic Metabolism
• Aerobic Metabolism

Question 2

What is a limitation of using ATP for muscle contraction?

Answer 2

• There are limited stores of ATP in muscle

Question 3

The breakdown of Creatine + Phosphate can resynthesise the…

Answer 3

• ATP

Question 4

What’re some features of anaerobic respiration?

Answer 4

• Short term
• Fast energy production
• No O2 required
• ATP, CP, glycolysis

Question 5

What’re some features of aerobic respiration?

Answer 5

• Long term, steady
• Slower energy production
• O2 required
• Oxidative phosphorylation

Question 6

Out of Excitation, Contraction, and Relaxation, which stage requires energy?

Answer 6

• Relaxation
• Need ATP to uncouple the cross-bridge
• Need ATP to re-uptake Calcium into the SR

Question 7

No ATP?…

Answer 7

• RIGOR MORTIS

Question 8

Oxygen binds to ______ in the blood, and ______ in muscle. Both pigments colour red due to oxygen _____ binding.

Answer 8

• Haemoglobin
• Myoglobin (only one iron group)
• Iron

Question 9

The soleus muscle tenses slowly and help with…

Answer 9

• Posture

Question 10

Different type of muscle fibre types:

Answer 10

• Slow (Myosin Type I) Red
• Intermediate (Myosin Type IIA) Intermediate
• Fast (Myosin Type IIX) White

Question 11

Feature of Slow Muscles (Myosin Type I)

Answer 11

• Slow rate interaction w/ actin
• Slow force production
• Slow energy consumption

Question 12

Depending on their function muscles are dominated by one fibre type or….

Answer 12

• A mix of fibre types

Question 13

World class sprinters need explosive power, short duration, anaerobic metabolism, need relative less oxygen. This means that their leg muscles develop more….

Answer 13

• White (Fast) muscle

Question 14

World class endurance athlete needs fatigue resistance, slower pace, uses aerobic metabolism

Answer 14

• Much higher proportion of slow/red and intermediate muscle fibre types (+ adaptations for supply of O2)

Question 15

A single electrical stimulation of a muscle -> a single activation of may motor units =

Answer 15

• A twitch in the muscle

Question 16

A twitch is a ______ event. To build up and _____ tension in a muscle takes longer than underlying _____ processes.

Answer 16

• Mechanical
• Decline
• Biochemical

Question 17

In a series of spaced twitches a ______ effect occurs. This is due to sustained higher levels of sarcoplasmic ____. Actin-myosin interactions become more _____ to ____. At higher temperature, _____ tension can be produced.

Answer 17

• “Treppe” (Staircase)
• Ca2+
• Sensitive
• Ca2+
• More

Question 18

In a series of closely spaced twitches, there can be incomplete tetanus or _____ tetanus. It’s called tetanus after the bacterial infection. “Summation” = ____. Main mechanism of summation is due to _____ _____ of ___ in sarcoplasm.

Answer 18

• Complete
• More tension
• High levels
• Ca2+

Question 19

Hypertrophy is the…

Answer 19

• Increase in number of contractile filaments
• More power
• Strength Training

Question 20

Atrophy is the….

Answer 20

• Loss of number of contractile filaments

- Disuse

Question 21

In Endurance training there needs to be an increased blood supply to muscle, therefore there’s a higher number of….Also increased ______ metabolism.

Answer 21

• Blood Vessels
• Mitochondria
• Aerobic enzymes
• Aerobic

Question 22

What occurs during Exhaustion?

Answer 22

• Physiological fatigue
• Depletion of ATP, Glucose, Glycogen, O2
• Build up of metabolic by-products e.g. lactic acid
• Psychological fatigue
• Fatigue from working muscles to brain produces sensation of fatigue, even though muscle is still capable of contracting