Neuromuscular Properties

Question 1

hierarchy of muscle structure

Answer 1

Tendon
Deep Fascia
Epimysium
blood vessels
Perimysium
Fascile
Endomysium
Muscle Fiber
Blood capillary
Sarcolemma
Myofibril- Sarcomeres, myofilaments, actin and myosin

Question 2

What makes up a Sarcolemma

Answer 2

Ion Channels and pumps

Hormone receptors(receive neurotransmitters)

Enzyme and binding proteins structural proteins

Question 3

myofibril and sarcomere structure

Answer 3

myofibrils are made up of repeating units of Actin and Myosin called Sarcomeres

Question 4

Excitation contraction coupling

Answer 4

Action potential reaches neuromuscular junction

ACh is released from presynaptic terminal to p.s receptor in the muscle

ACh continues action potential and action potential travels down Sarcolemma with help of ATP

AP goes into T tubules and Ca2+ is released from sarcoplasmic reticulum

Ca2+ assists in cross-bridge cycling with the

Question 5

Two pumps in excitation-contraction coupling

Answer 5

one that keep AP in sarcolemma
Na+ - K+ ATPase

forces Ca2+ out of sarcoplasm and back into sarcoplasmic reticulum
SERCA pump

Question 6

Cross bridge cycle

Answer 6

ADP myosin head is ready to bind to actin

Ca2+ changes troponin and tropomyosin and exposing binding sites

Bound myosin head does a power stroke and loses its ADP

ATP binds to head and allows it to unattach

ATP then hydrolysates and ADP is back on myosin head

NEED ATP FOR IT TO UNATTACH

Question 7

types of muscle contractions

how myosin and actin interact

Answer 7

ICE
isometric= no movement and some actin-myosin overlap

Concentric- muscles shortening and actin slides over myosin

Eccentric- lengthening, pulls actin away from myosin and sarcomeres lengthen

Question 8

Force length relationship

Answer 8

what is optimal length for active force

too short, too much myosin attached
too long, too little myosin attached

Just right amount of myosin bound

not too short not too long

Question 9

Force frequency relationship

Answer 9

1 Hz is one stimulus per second

forces add up on each other and don’t allow for muscle relaxation

SUF

single muscle twitch

Unfused tetanus

Fused Tetanus

Question 10

Force velocity relationship

Answer 10

slower the shortening of the muscles, the greater FORCE they can produce

INVERSE RELATIONSHIP

Question 11

Power velocity relationship

Answer 11

P = F x V

power includes velocity around a joint

slow muscle contraction, no power bc high force but no V

1/3 of Velocity max is greatest Power

Really fast contraction no power bc high V but no F