Muscles

Question 1

3 types of muscle

Answer 1

Skeletal - attaches to bones
Cardiac - walls of heart, pumping of heart
Smooth - walls of internal organs (dig. tract)

Question 2

muscle tissue coverings

Answer 2

Epimysium: surrounds whole muscle
Perimysium: surrounds fascicles within a muscle
Endomysium: surrounds muscle fibers (cells) within a fascicle

Fascia: connective tissue that separates muscles and holds them in position
Deep- surrounds muscle
Subcutaneous- below skin
Subserous- surrounds organs

Question 3

muscle fatigue

Answer 3

Muscle Fatigue: Inability to contract muscle

Common causes of muscle fatigue:
Decreased blood flow
Ion imbalances across the sarcolemma
Loss of desire to continue exercise
Accumulation of lactic acid (controversial)

Question 4

Cellular Respiration Anaerobic

Answer 4

Anaerobic Phase:

• Glycolysis
• Occurs in cytoplasm
• Produces little ATP

Question 5

Cellular Respiration Aerobic

Answer 5

Aerobic Phase:

• Citric acid cycle and electron transport system
• Occurs in the mitochondria
• Produces the most ATP
• Myoglobin stores extra oxygen in muscles

Question 6

Muscle Contraction

Answer 6

1. ) Acetylcholine (ACh) is the neurotransmitter
2. ) Nerve impulse causes release of ACh from synaptic vesicles
3. ) ACh binds to ACh receptors on motor end plate ACh causes changes in membrane permeability to Na+ and K+ ions, which generates a muscle impulse (action potential)
4. ) Impulse causes release of Ca+2 from SR, which leads to muscle contraction

Question 7

Muscle Relaxation

Answer 7

1. ) Acetylcholinesterase (enzyme) rapidly decomposes ACh remaining in the synapse
2. ) Muscle impulse stops when ACh is decomposed
3. ) Stimulus to sarcolemma and muscle fiber membrane ceases
4. ) Calcium pump moves Ca+2 back into sarcoplasmic reticulum (SR)
5. ) Troponin-tropomyosin complex again covers binding sites on actin

6.)Myosin and actin binding are now prevented
Muscle fiber relaxes

Question 8

Neuromuscular Junction

Answer 8

Site where an axon of motor neuron and skeletal muscle fiber interact

Parts of a NMJ:
 Motor neuron
 Motor end plate 
 Synaptic cleft
 Synaptic vesicles
 Neurotransmitters

Question 9

Myofibrils

Answer 9

Actin - thing filaments

Mysoin - thick filaments

Question 10

Hypertrophy / Atrophy

Answer 10

Hypertrophy: Enlargement of skeletal muscle that is exercised
Atrophy: Decrease in size and strength of skeletal muscle that is unused

Question 11

Skeletal Muscle Characteristics

Answer 11

striated
multiple nuclei
voluntary

Question 12

Smooth Muscle Characteristics

Answer 12

non striated
single nuclei
involuntary

Question 13

Cardiac Muscle Characteristics

Answer 13

striated
single nuclei
involuntary

Question 14

2 types of smooth muscle

Answer 14

Multi-unit Smooth Muscle:
Cells are less organized
Iris of eye, walls of blood vessels
Stimulated by neurons, hormones

Visceral Smooth Muscle:
Single-unit smooth muscle; cells respond as a unit
Walls of most hollow organs
More common type of smooth muscle

Question 15

Muscle Movement:
Agonist
Synergists
Antagonist

Answer 15

Agonist (Prime Mover): muscle that causes an action

Synergists: muscles that assist agonist / prime mover

Antagonist: muscles whose contraction causes movement in the opposite direction of the prime mover

Question 16

origin/insertion:

Sternocleidomastoid

Answer 16

origin: Sternum / Clavicle
insertion: Mastoid process of temporal bone

Question 17

origin/insertion:

Temporalis

Answer 17

origin: Temporal Bone
insertion: Coronoid Process of mandible

Question 18

origin/insertion:

Latissimus Dorsi

Answer 18

origin: Spines of thoracic/lumber vert., Ribs, Illiac crest
insertion: Humerus

Question 19

origin/insertion:

Biceps Bracchi

Answer 19

origin: Coracoid Process
insertion: Radial Tuberosity