Unit 2 Additional Reading Vocab

Question 1

Myasthenia Gravis

Answer 1

autoimmune disease that causes chronic, progressive damage of neuromuscular junction where immune system inappropriately produces antibodies that bind to & block ACh receptors

Question 2

Muscular Dystrophy

Answer 2

group of inherited muscle-destroying diseases that cause progressive degenerative of skeletal muscle fibers

Question 3

Spasm

Answer 3

sudden involuntary contraction of single muscle in large group of muscles

Question 4

Cramp

Answer 4

painful spasmodic contraction, caused by inadequate blood flow to muscles, overuse of muscle, dehydration, injury, holding same position for too long, & low blood levels of electrolytes (ie. potassium)

Question 5

Tic

Answer 5

spasmodic twitching made involuntarily by muscles that are ordinarily under voluntary control

Question 6

Tremor

Answer 6

rhythmic, involuntary, purposeless contraction that produces quivering or shaking movement

Question 7

Fasciculation

Answer 7

involuntary, brief twitch of an entire motor unit that’s visible under skin; occurs irregularly and isn’t associated with movement of affected muscle

Question 8

Fibrillation

Answer 8

spontaneous contraction of single muscle fiber that isn’t visible under skin but can be recorded by electromyography ⇒ can signal destruction of motor neurons

Question 9

Theories of Delayed Onset Muscle Soreness (DOMS)

Answer 9

1. Mechanical trauma: mechanical forces in contractile or elastic tissue ⇒ structural damage to muscle fibers
2. Local ischemic: exercise (even moderate, atraumatic activities) causes swelling in muscle tissue ⇒ increases tissue pressure ⇒ local ischemic (reduced blood flow) ⇒ structural damage that leads to inflammation and swelling ⇒ exacerbates cycle

Question 10

Theories of Muscle Fatigue

Answer 10

1. Central fatigue
2. Inadequate release of Ca+ from SR
3. Depletion of creatine phosphate
4. Insufficient oxygen
5. Depletion of glycogen and other nutrients
6. Buildup of lactate
7. Failure of action potential to trigger and release ACh