Muscular System

Question 0

Muscle Fibers?

Answer 0

Muscle cell, arranged parallel to each other.

Question 1

Fascia?

Answer 1

Holds muscles together, forms groups, deep fascia.

Question 2

Epimysium?

Answer 2

Connective tissue around entire muscle.

Question 3

Perimysium?

Answer 3

Surrounds bundles of muscle fibers or fascicles.

Question 4

Fasicles?

Answer 4

Bundles of muscle fibers.

Question 5

Endomysium?

Answer 5

Wraps each individual muscle fibers.

Question 6

Tendons?

Answer 6

Attach muscle to bone.

Question 7

Sarcolemma?

Answer 7

Plasma membrane around muscle fiber.

Question 8

T Tubules? “transverse tubules”

Answer 8

Connect the muscle fibers, continuous with sarcolemma.

Question 9

Sarcoplasmic Reticulum?

Answer 9

Membranous network similar to ER, stores Ca++ for contraction.

Question 10

Myoglobin?

Answer 10

Pigment similar to Hb for oxygen carrying.

Question 11

Myofibrils?

Answer 11

Protein filaments running length of fibers, but not continuous.

Question 12

Thin Filament?

Answer 12

Contains actin, troponin & tropomyosin.

Question 13

Thick Filament?

Answer 13

Contains myosin.

Question 14

Sarcomeres?

Answer 14

Basic functional unit of skeletal muscle (striated).

Question 15

Z Discs?

Answer 15

Zigzag of dense material separating sarcomeres.

Question 16

Myosin?

Answer 16

Golf club shaped protein, form crossbridge.

Question 17

Actin?

Answer 17

Helix shape, anchored to Z disc, has myosin-binding sites.

Question 18

Tropomyosin & Troponin?

Answer 18

Both cover myosin binding sites on relaxed muscle.

Question 19

Sliding Filaments?

Answer 19

Filament length does not change even though the fibers change and slide past each other.

Question 20

Action Potential?

Answer 20

Electrical signal/ stimulus.

Question 21

Motor Neuron?

Answer 21

Neuron delivering stimulus to muscle.

Question 22

Motor Unit?

Answer 22

Single motor neuron & all of the fibers it stimulates, size of motor unit varies with the precision of movement.

Question 23

Motor Endplate?

Answer 23

The region of sarcolemma that connects to the nerve.

Question 24

Synaptic Cleft?

Answer 24

Space between axon end of nerve & motor endplate.

Question 25

First step of excitement of skeletal muscle (at the neuromuscular junction)?

Answer 25

Release AcH: diffuse across synaptic cleft.

Question 26

Second step of excitement of skeletal muscle (at the neuromuscular junction)?

Answer 26

Activation of AcH: binds to motor endplates & opens Na+ ion channels

Question 27

Third step of excitement of skeletal muscle (at the neuromuscular junction)?

Answer 27

Generates action potential: flow of Na+ generates action potential along sarcolemma.

Question 28

Fourth step of excitement of skeletal muscle (at the neuromuscular junction)?

Answer 28

Breakdown AcH: Ach esterase breaks down Ach in synaptic cleft.

Question 29

Creatine Phosphate?

Answer 29

Short term, not useful for endurance, extra supply of phosphate when ATP supply is depleted to ADP.

Question 30

Anaerobic Glycolysis/Metabolism?

Answer 30

After about 15secs, creatine phosphate is depleted, process to breaking down glucose to pyruvate for more ATP, last 30-40secs (short term) (fee ATP)

Question 31

Aerobic Respiration/Metabolism?

Answer 31

In presence of oxygen (aerobic), pyruvate broken down further for more ATP, uses Krebs cycle & electron transport chain (in mitochondria), ( long term) (high amount of ATP)

Question 32

Muscle Fatigue?

Answer 32

Inability to contract forcefully after prolonged activity. depletion of Ca++, Creatine phosphate, glycogen, Ach.

Question 33

Recovery?

Answer 33

Need to increase oxygen after exercise for increased tissue repairs, heart still working harder and increase in body reactions= body still need more oxygen.

Question 34

Skelatal Muscle Fibers?

Answer 34

Slow oxidative fiber, fast oxidative fiber, fast glycolytic fibers

Question 35

Slow Oxidative Fibers?

Answer 35

Red fibers, high in myoglobin, small diameter, slow pace contraction, fatigue resistant, many mitochondria, (endurance training)

Question 36

Fast Oxidative Fibers?

Answer 36

Dark red, some myoglobin, medium diameter fibers, moderate strength, some glycogen, some mitochondria, moderate fatigue, (makes mod. ATP, moderate resistance, intermediate size)

Question 37

Fast Glycolytic Fibers?

Answer 37

White fibers, low in myoglobin, large diameter fibers, powerful, high strength, high in glycogen, low in mitochondria, fatigue rapidly, (strength training)