Muscle.

Question 1

Blood vessels and nerves follow what in the muscle organization/

Answer 1

Epimysium and Perimysium.

Question 2

when are fast and slow muscle fibers differentiated?

Answer 2

Early in development, the different types become inner ate during by either the fast or the slow twitch neurons.

Question 3

What are the two intermediate muscle fibers?

Answer 3

Type II a- mix of type 1 and type 2 muscle fibers. oxidative and fatigue resistant.

Type II b- glycolytic and fatigue sensitive. (Classic type II)

Question 4

During peak exertion, both type I and type II fibers use glycolysis for anaerobic respiration. If the oxygen debt becomes severe, what can happen?

Answer 4

ischemia — lack of blood flow and leads to cramps

Question 5

Sarcopenia:

Answer 5

Loss of skeletal muscle fibers. Often happens with old age.

Question 6

Sarcoplasmic reticulum and terminal cisternae act as what when the muscle is relaxed?

Answer 6

Calcium reservoirs

Question 7

Physiology of the muscle contraction

Answer 7

Ca is released from the Er and the terminal cisternae.

1. Activates the sliding filament mechanism:
2. CA causes conformational change on troponin which interacts with tropomyosin molecules (bound to actin), exposing the myosin-binding site on actin filament.
3. Myosin binding causes conformational change in myosin head and sliding of myosin past actin.
4. Myosin heads repeatedly bind and unbind in the presence of Ca and Pi

Question 8

There is a form of muscular dystrophy that affects a specific protein. what is that protein?

Answer 8

Dystrophin

Question 9

How is myasthenia gravis treated?

Answer 9

With acetylcholase inhibitors. This only acts briefly.

Question 10

Smooth muscle cells lack troponin. Troponin is a complex that controls myosin binding. So, what does smooth muscle use instead for myosin cross binding.

Answer 10

Calmodulin

Question 11

T or F: Smooth muscles retain the ability to divide and repair themselves.

Answer 11

True

Question 12

Where do smooth muscles develop from?

Answer 12

Endothelial cells, pericytes of blood vessels, and fibroblasts!

Question 13

Where are blood vessels and nerves located for the heart?

Answer 13

Within the subepicardial layer

Question 14

How are the functional/ contractile units of cardiac muscle arranged?

Answer 14

They are arranged in a diad fashion compared to skeletal muscles triad fashion.

Cardiac: 1 cisterna of the Er and one T tubule located at the z disc.

Skeletal: 2 cisterna and one t tubule

Question 15

Some valves occasionally ossify to form bony rings at the base of AV valves. What is this called?

Answer 15

Os cordis