Musculoskeletal System

Question 1

Red fibers (slow-twitch)

Answer 1

High myoglobin content, aeorbic with many mitochondria

Question 2

White fibers (fast-twitch)

Answer 2

Low myoglobin, less iron

Question 3

Muscles that contract slowly but sustain activity

Answer 3

Red fibers

Question 4

Muscles that contract rapidly but fatigue quickly

Answer 4

White fibers

Question 5

Smooth muscle

Answer 5

Involuntary action, single nucleus, striations not visible

Question 6

Skeletal muscle

Answer 6

Voluntary action, multinucleus, striated

Question 7

Red fibers and white fibers are types of

Answer 7

Skeletal muscle

Question 8

Myogenic activity

Answer 8

Muscle contracts without nervous system input

Question 9

Myogenic activity is found in

Answer 9

Smooth and cardiac muscle

Question 10

Cardiac muscle

Answer 10

Primary uninucleus but may contain two nuclei, involuntary, striated

Question 11

Cardiac and smooth muscle are innervated by

Answer 11

Autonomic nervous system

Question 12

Thick filaments are made of

Answer 12

Myosin

Question 13

Thin filaments are made of

Answer 13

Actin, troponin, tropomyosin

Question 14

Z-line

Answer 14

End of the sarcomere

Question 15

M-line

Answer 15

Middle of myosin filaments

Question 16

I-band

Answer 16

Thin filaments only

Question 17

H-zone

Answer 17

Thick filaments only

Question 18

A-band

Answer 18

All thick filaments

Question 19

What band’s size remains constant during contraction

Answer 19

A-band

Question 20

Sarcoplasmic reticulum

Answer 20

Modified endoplasmic reticulum with high [Ca2+]

Question 21

Sarcolemma

Answer 21

Cell membrane of muscle cell, can propagate action potential

Question 22

Muscle fiber vs myofibril

Answer 22

Muscle fiber consists of many myofibrils

Question 23

Myofibril

Answer 23

Consists of many sarcomeres in series

Question 24

T-tubules

Answer 24

Connected to sarcolemma, distributes action potential across muscle

Question 25

Tetanus

Answer 25

Muscle contractions too frequent -> stronger, prolonged contraction of muscle

Question 26

Osteoblast

Answer 26

Build bone

Question 27

Osteoclast

Answer 27

Chew (resorb) bone

Question 28

Hormone that promotes resorption of bone

Answer 28

PTH

Question 29

Hormone that promotes bone formation

Answer 29

Calcitonin

Question 30

Chondrocytes

Answer 30

Form cartilage

Question 31

Spongy (cancellous bone)

Answer 31

Site of marrow production

Question 32

Bones are attached to muscle by

Answer 32

Tendon

Question 33

Bones are attached to each other at joints by

Answer 33

Ligament

Question 34

Axial skeleton

Answer 34

Midline structures e.g. skull, vetebral column, ribcage, hyoid

Question 35

Appendicular skeleton

Answer 35

Limbs, pelvis, pectoral girdle

Question 36

Immovable joint

Answer 36

Bones that are fused together to form sutures

Question 37

Movable joins

Answer 37

Strengthened by ligament, contain synovial capsule

Question 38

Synovial fluid

Answer 38

Lubricates the joint

Question 39

Lamellae

Answer 39

Circular rings of bone

Question 40

Canaliculi

Answer 40

Channels that allow for exchange of nutrients and waste

Question 41

Haversian and Volkmann's canals

Answer 41

Contain blood vessels, nerves, and lymph vessels in bone

Question 42

Lacunae

Answer 42

Osteocyte location

Question 43

Epiphysis

Answer 43

End part of long bone

Question 44

Metaphysis

Answer 44

Neck part where long bone flares

Question 45

Diaphysis

Answer 45

Middle part of long bone

Question 46

What provides the powerstroke

Answer 46

Release of ADP and Pi from myosin

Question 47

Muscle contraction initiation

Answer 47

Release of acetylcholine from motor neuron -> activation of acetylcholine receptors in sarcolemma -> depolarization of sarcolemma -> T-tubules spread signal -> Ca2+ released from SR ->Ca2+ binds to troponin -> conformational shift in tropomyosin -> myosin binds to actin

Question 48

ATP binding role in actin-myosin cross-bridge cycle

Answer 48

Allows myosin to detach from actin

Question 49

Sliding filament model

Answer 49

Repetitive binding and sliding of myosin heads on actin allows thin filament to slide along thick filament, which leads to contraction