Skeletal Muscle Dynamics Flashcards Preview

Physiology (Autonomic Nervous System and Muscle) > Skeletal Muscle Dynamics > Flashcards

Flashcards in Skeletal Muscle Dynamics Deck (13)
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1
Q

Twitch vs. tetanus

A
Twitch = single impulse
Tetanus = maximum force resulting from increased frequency of stimulation
2
Q

Internal and external elastic elements of muscle?

A
Internal = titin and nebulin
External = tendons and connective tissue
3
Q

Components of sarcomere (Z-disk, etc)

A

Z-disk = edges of sarcomere
M line = middle of sarcomere
A- band = length of thick filaments

4
Q

Molecular mechanism of muscle contraction

A

ATP binds to myosin
ATP hydrolyzed and myosin moves down actin chain
ADP removed and cycle starts again

5
Q

Control of muscle contraction

A

Tropomyosin in the way during relaxed state. Calcium must bind to troponin during contraction, troponin moves tropomyosin out of the way

6
Q

What is the preload?

A

The force that sets the initial length of and establishes the degree of crossbridge overlap at the initiation of muscle contraction

7
Q

What is the afterload?

A

The force that opposes the muscle’s shortening. The load the muscle is attempting to move

8
Q

What is a motor unit?

A

A motor unit consists of a motor neuron and the collection of muscles it innervates

9
Q

Components of muscle fiber type I

A

Small size
Slow
Red
Oxidative metabolism

10
Q

Components of muscle fiber type IIa

A

Medium size
Intermediate speed
Red
Glycolytic/oxidative metabolism

11
Q

Components of muscle fiber type II

A

Large size
Fast
White
Glycolytic metabolism

12
Q

Fine motor control involves…?

A

Small muscle cells for control of delicate tasks

13
Q

Load based control involves…?

A

Small fatigue resistant muscle fibers recruited first. As load increases, larger muscle fibers added