Physiology of Muscle

Question 1

What are the physiological functions of skeletal muscle?

Answer 1

• maintenance of posture
• purposeful movement
• respiratory movements
• heat production
• whole body metabolism

Question 2

What are the 3 types of muscle?

Answer 2

skeletal, cardiac and smooth

Question 3

What type of muscles are skeletal and cardiac muscles?

Answer 3

striated

Question 4

What type of muscles are smooth muscles?

Answer 4

unstriated

Question 5

What forms the darks bands of striation?

Answer 5

thick myosin filaments

Question 6

What forms the light bands of striation?

Answer 6

thin actin filaments

Question 7

What muscles innervated by somatic control?

Answer 7

skeletal muscles

Question 8

What muscles are under voluntary control?

Answer 8

skeletal muscles

Question 9

What muscles are innervated by autonomic control?

Answer 9

cardiac and smooth muscles

Question 10

What muscles are under involuntary control?

Answer 10

cardiac and smooth muscles

Question 11

What is the neurotransmitter at the neuromuscular junction?

Answer 11

acetylcholine

Question 12

What is the motor unit?

Answer 12

a single alpha motor neurone and all the skeletal muscle fibres it innervates

Question 13

Do precise movements require more or less muscle fibres in the motor unit?

Answer 13

less

precision>power=less and power>precision=more

Question 14

What usually attaches skeletal muscles to bones?

Answer 14

tendons

Question 15

What do muscles fibres (cells) contain?

Answer 15

many myofibrils (specialised contractile intracellular structures

Question 16

What are sarcomeres?

Answer 16

actin and myocin are arranged into these (functional units of the muscle

Question 17

What is the functional unit of any organ?

Answer 17

the smallest component capable of performing all the functions of the organ

Question 18

What are the Z lines?

Answer 18

the boundaries of the sarcomere, connects the thin filaments of 2 adjoining sarcomeres

Question 19

What is the A band?

Answer 19

thick filaments and the. areas of thin filaments that overlap the thick filaments

Question 20

What is the H zone?

Answer 20

area of thick filaments that the thin filaments don’t reach

Question 21

What is the I band?

Answer 21

remaining thin filaments that don’t contribute to the A band

Question 22

What is the M line?

Answer 22

extends through the middle of the A band and H zone

Question 23

What produces muscle tension?

Answer 23

sliding of actin filaments on myosin filaments

Question 24

What is ATP required for?

Answer 24

contraction and relaxation

Question 25

What is Ca++ required for?

Answer 25

switch on cross bridge formation

Question 26

What is excitation contraction coupling?

Answer 26

the forces whereby the surface action potential results in activation of the contractile structures of the muscle fibre

Question 27

Where is the Ca++ released from?

Answer 27

lateral sacs of the sarcoplasmic reticulum

Question 28

What triggers the release of Ca++ from lateral sacs of sarcoplasmic reticulum?

Answer 28

spread of action potential down T-tubules

Question 29

When the muscle fibre is relaxed why is there no cross bridge binding?

Answer 29

the cross bridge binding site on actin is occupied by the troponin-tropomyosin complex