Sliding Filament Theory

Question 1

Sarcotubular system is located

Answer 1

within the muscle cell but outside of the myofibrils

Question 2

Sarcoplasmic reticulum encircle and are parallel to the

Answer 2

myofibrils

Question 3

Terminal cisternae are

Answer 3

bulbous ends of the sarcoplasmic reticulum

Question 4

T tubules (transverse tubules) are

Answer 4

indentations of the sarcolemma and perpendicular to myofibrills

Question 5

Triad are T tubules and the 2 adjacent …

Answer 5

terminal cisternae

Question 6

Difference in red fibers and white fibers

Answer 6

Red fibers are smaller in size than white fibers, better supplied with capillaries, and contain more mitochondria

Question 7

Between red and white muscle fibers, which ones are aerobic and which ones are anaerobic

Answer 7

Red are aerobic
White are anaerobic

Question 8

Thoroughbreds have the highest percentage of ____ fibers and Belgians have the most _____ fibers

Answer 8

red
white

Question 9

Alpha motor neurons are

Answer 9

efferent, motor neurons that leave from the CNS (brainstem and ventral region of the spinal cord)

Question 10

Alpha motor neurons innervate extrafusal muscle fibers which are

Answer 10

skeletal muscles that contract, generate tension and move skeletal elements of the body

Question 11

Alpha motor neurons are considered part of the SNS which is a part of the

Answer 11

peripheral nervous system

Question 12

Motor unit

Answer 12

each alpha motor neuron can diverge and innervate many skeletal muscle cells
many or few terminal ends

Question 13

A motor unit is one

Answer 13

Alpha Motor Neuron and all the muscle cells that it innervates

Question 14

The ratio (1:5 vs 1:100) of alpha motor neuron to skeletal muscle cells gives an idea of

Answer 14

the precision of muscle control

Question 15

Small motor units control

Answer 15

eye muscles, fine movement, and works slower

Question 16

Large motor units control

Answer 16

powerful “gross” muscle movement such as your back muscles

Question 17

Degeneration, atrophy is when you

Answer 17

cut nerves to a muscle

Question 18

When you cut nerves to a muscle, what may regrow?

Answer 18

Axon

Question 19

NCB is in the

Answer 19

spinal gray matter

Question 20

Neuromuscular Junction (NMJ) is where the

Answer 20

terminal end of an alpha motor neuron comes close to the motor end plate in the sarcolemma of a skeletal muscle cell

Question 21

How many NMJ are there per muscle fiber?

Answer 21

One

Question 22

When ACh is binding to ACh receptor on the MEP-

Answer 22

1:1 transmission (unlike synapse)

Question 23

EPP

Answer 23

End Plate Potential and always reaches TP (unlike EPSP) where we had to sum together

Question 24

How is NMJ like synapse?

Answer 24

susceptible

Question 25

Acetylcholine contain

Answer 25

nicotinic receptors on Motor End Plate of NMJ

Question 26

Nicotine can mimic

Answer 26

the effect of Ach at the NMJ

Question 27

Quanta release small amounts of ____ which keeps the ____ ____ ______ slightly above normal resting potential (closer to _______ ________) thus making it easier to reach TP of the _________

Answer 27

small amounts of ACh which keeps the Motor End Plate slightly above normal resting potential (closer to Threshold Potential) thus making it easier to reach TP of the sarcolemma

Question 28

ACh at NMJ

Answer 28

(like NT at synapse) binds to receptors

Question 29

T-tubule is an

Answer 29

indentation in the sarcolemma, as AP goes over sarcolemma and down T-tubule to Terminal Cisternae to sarcoplasmic reticulum

Question 30

Myosin heads have 2 binding sites

Answer 30

ATP site with ATPase activated with ADP and PO4
Actin binding site

Question 31

Myosin binding sites on Actin uncovered…

Answer 31

Myosin binds actin-> Actomyosin

Question 32

ATP binds to its site on Myosin

Answer 32

changes affinity releases actin

Question 33

Energy from ATP hydrolysis rotates

Answer 33

myosin, binds new G-actin site, release Pi, push actin toward center of sarcomere=powerstroke

Question 34

Myosin head tilts from

Answer 34

90 to 45 degrees

Question 35

Myosin releases ADP which

Answer 35

binds to actin which leads to actomyosin

Question 36

Calcium influx needed for

Answer 36

ACh release at the NMJ into the alpha motor neuron terminal end

Question 37

Milk cows after calving have low

Answer 37

intestinal fluid calcium which leads to milk fever (parturient paresis)

Question 38

A milk fever cow has an

Answer 38

S-shaped neck
Feces in rectum
Down (not standing)

Question 39

Symptoms of a milk fever cow

Answer 39

Loss of appetite
followed by muscle weakness and paralysis of hind legs

Question 40

Conditions of a milk fever cow occurs

Answer 40

within 3 days of calving

Question 41

Treatment for a milk fever cow

Answer 41

treat with IV solution of calcium gluconate or calcium boluses in the GI tract