Muscle Physiology Pt. 3

During muscle relaxation, what happens to the Ca that is bound to troponin?

It is removed via active transport and transported back to the terminal cistern

Why does muscle relax?

Action potential stops

What does tropomyosin do when muscle relaxes?

Blocks the actin site again

What does the recruitment of more muscle cells lead to?

Greater contraction

A higher amount of muscle contraction = ______ Muscle fibers engaged

Increase of-

What are graded contractions controlled by?

Nervous system

What happens when you stimulate increasing numbers of cells or motor units?

Increase the force of contraction

What is the muscle twitch?

A single response to a single stimulus

One stimuli = ___ twitch

One

What is it called when there are ~3 stimuli?

Wave summation

What is it called when there are multiple stimuli?

Incomplete tetanus

What is it called when there are a lot of stimuli back to back?

Complete tetanus

What does wave summation result from?

Stimulating a muscle before it had time to relax from a previous stimuli

What are you doing to the frequency of the stimuli when wave summation occurs?

Increasing it

What is tetany?

Comes after wave summation; it is a sustained muscle contraction

What can cause tetanus?

A bacterial toxin called clostridium tetnai

How often should people get vaccinated against tetany?

Every 10 years

What is Treppe?

The staircase effect

Explain Treppe

Its a step-like increase in the force of contraction until a uniform tension is reached. So muscles exhibit gradually increasing responses until they have warmed up

What is treppe caused by?

Increasing efficiency of the ion gates as they are repeatedly stimulated

T/F Treppe requires stimulation of the same intensity and frequency

True

What makes treppe differ from tetanus?

Tetanus has a stimulus and is followed by another stimuli before it can completely relax, which causes a more powerful contraction.

Treppe has a stimulation of the same intensity and frequency so it forms a staircase

What is Muscle Atrophy?

Decrease in muscle size

What happens to blood flow and fluid in the muscle when there is atrophy?

They decrease

What is hypertrophy?

Increase in muscle size

What is normal growth of muscle?

Hyperplasia of muscle cells

What is hyperplasia of muscle cells influenced by?

GH and IGF

What happens when you get a charlie horse?

Your muscle gets locked in a contracted state

What is exertional myopathy?

muscle damage due to intense physical exertion

What is myasthenia gravis?

It affects the neuromuscular junction. it is chronic muscle weakness disease

What is denervation?

The loss of nerves

What are examples of CNS disorder?

Disc disease and equine protozoa My.