Muscles (M+) And Movements

Question 1

3 things skeletal muscle must do

Answer 1

1-muscles have at least 2 attachments, must cross at least 1 joint
2-to produce movement, muscles always pull and get shorter (distal moves to proximal; insertion moves to origin)
3- muscle fibers or “striations” ALWAYS POINT to their attachments and show direction of pull

Question 2

Flexor

Answer 2

When a muscle moves central to ventral (angle decreases)

Question 3

Extensor

Answer 3

Muscles move the dorsal side to dorsal side (angle increases)

Question 4

Filaments

Answer 4

Smallest component of M+

Question 5

Myofibrils

Answer 5

Filaments clustered together

Question 6

Muscle fibers

Answer 6

Myofibrils clustered together

Question 7

Fascicle

Answer 7

A cluster of muscle fibers

Question 8

Muscle

Answer 8

Fascicles clustered together

Question 9

Epimysium

Answer 9

Layer of ct around whole tissue

Question 10

Perimysium

Answer 10

Surrounds individual fascicles within each muscle

Question 11

Endomysium

Answer 11

Covering each muscle fiber

Question 12

Sacromere

Answer 12

This is the “functional unit” of the muscle cell/fiber where actual contraction happens

Question 13

Muscle cramps are caused by…

Answer 13

1-if ATP doesn’t show up

2-dehydration or electrolyte imbalance

Question 14

1) latent period

Answer 14

A lot happens here but doesn’t show up in the graph, motor neuron stimulates SR->SR releases Ca++ -> Ca++ binds to troponin complex and opens binding sites

Question 15

2)period of contraction

Answer 15

Cross fridge attach and power strokes follow (CONTRACTION)

Question 16

3)period of relaxation

Answer 16

The stimulus ends -> Ca++ is pumped back into SR -> binding sites close (RELAXATION)

Question 17

Treppe

Answer 17

If repetitive contractions follow each other, the relation phase is not complete, leaving more Ca++ in the matrix because SR can’t pump it out all the time. This results in the following contraction to be more powerful than the one before it. Eventually M+ can run out of ATP causing myosin to be locked in power stroke known as a cramp or tetanus

Question 18

Isometric exercise

Answer 18

M+ is contracting but CANNOT move the load this type of exercise is used in rehabilitation and keep M+ “toned” when the area of movement is limited

Question 19

Isotonic

Answer 19

M+ contracts and CAN move the load. This is the most common form of exercise

Question 20

Concentric

Answer 20

When the M+ is shorting (for everyone-velocity relationship)

Question 21

Eccentric

Answer 21

When the M+ is being lengthened in a controlled manner