Muscloskeletal system (11)

Question 1

Skeletal Muscle

Answer 1

Striated, Voluntary, Somatic innervation, Many nuclei per cell. Calcium required for contraction.

Question 2

Cardiac Muscle

Answer 2

Striated, Involuntary, Autonomic innervation, 1-2 nuclei per cell. Calcium required for contraction.

connected by intercalated discs that contain many gap junctions.

Question 3

Smooth Muscle

Answer 3

Non-striated, Involuntary, Autonomic innervation, 1 nucleus per cell. Calcium required for contraction.

Question 4

Red fibers ( slow-twitch fibers)

Answer 4

have high myoglobin content and primarily derive their energy aerobically.

Muscle fibers have high levels of mitochondria and thus have to use oxidative phosphorylation to make ATP.

Question 5

White fibers ( fast-twitch fibers)

Answer 5

contain less myoglobin.

Muscle fibers have fewer mitochondria and must rely on glycolysis and fermentation to make ATP under most circumstances.

Question 6

Sacromere

Answer 6

basic contractile unit of skeletal muscle

Question 7

Troponin and Tropomyosin

Answer 7

found on the thin filament and regulate actin-myosin interactions.

Calcium binds to troponin, leading to a conformational change in tropomyosin, which exposes the myosin-binding sites of actin.

Question 8

Z-line

Answer 8

boundaries of each sacromere

Question 9

M-line

Answer 9

middle of the sacromere

Question 10

I-band

Answer 10

contains only thin filaments

Question 11

H-zone

Answer 11

contains only thick filaments

Question 12

A-band

Answer 12

contains thick filaments in thier entirety. It is only part of the sacromere that maintains a constant size during contraction.

Question 13

Neuromuscular junction

Answer 13

motor neurons release ACh that binds to receptors on the sarcolemma, causing depolarization.

• This depolarization spreads down the sarcolemma to the T-tubules, triggering release of calcium ions.
• Calcium binds to troponin, causing shift in tropomyosin and exposure of myosin-binding sites on the actin thin filament

Question 14

Sliding filament model

Answer 14

shortening of the sarcomete occurs as myosin heads binds to the exposed sites on actin, forming cross bridges and pulling the actin filament along on the thick filament, results in contraction.

Question 15

Muscle relax

Answer 15

muscle relaxes when ACh is degraded by acetylcholinesterase. terminating the singal and allowing to calcium to brought back into SR, ATP binds to the myosin head, allowing it to release from actin.

Question 16

Simple twitch

Answer 16

the response of a single muscle fiber to a brief stimulus at or above threshold.

• Latent period: time between reaching threshold and onset of contraction. AP spreads along the muscle and allows for calcium to be released from the sarcoplasmic reticulum.
• Contraction period
• Relaxation period

Question 17

Tetanus

Answer 17

contractions become so frequent that the muscle is unable to relax at all.

Question 18

Frequency summation

Answer 18

multiple simple twitches before the muscle has an opportunity to fully relax.

Question 19

Oxygen debt

Answer 19

difference between amount of oxygen needed and the amount of oxygen present.

Question 20

Creatine phosphate

Answer 20

created by transferring a phosphate group from ATP to creatine during times of rest.

Question 21

Tendon

Answer 21

connect muscle to bone

Question 22

Ligament

Answer 22

hold bone to bone

Question 23

Osteoblasts

Answer 23

build the bone

Question 24

Osteoclasts

Answer 24

macrophage of bone, resorb it.

Question 25

Parathyroid horomone

Answer 25

response to low blood calcium, promotes resorption of bone, increasing the concentration of calcium and phosphate in the blood.

Question 26

Vitamin D

Answer 26

promotes resorption of bone leads to the production of strong bone.

Question 27

Calcitonin

Answer 27

Peptide hormone released by parafollicular cells in the thyroid. increases bone formation, decreasing calcium level in bone.

Question 28

Synovial fluid

Answer 28

secreted by synovium, aids in motion by lubricating the joint.

Question 29

Articular cartilage

Answer 29

aid in movement and provide cushioning.

Question 30

Events that initiates the muscle contraction

Answer 30

Release of Ach from motor neuron --> activation of Ach receptor in sarcolemma --> depolarization of sarcolemma --> spreading signal using T-tubules --> release of calcium from SR --> binding of calcium to troponin --> conformational shift in tropomyosin --> exposure of myosin-binding sites --> myosin binds to actin

Question 31

Red marrow

Answer 31

filled with hematopoietic stem cells, which are responsible for the generation of all cells in our blood

Question 32

Yellow marrow

Answer 32

composed primarily of fat and is relatively inactive

Question 33

Compact bone

Answer 33

provides strength and is dense

Question 34

Epiphysis

Answer 34

contains epiphyseal (growth) plate that causes linear growth of the bone

Question 35

Periosteum

Answer 35

bone is surrounded by a layer of connective tissue

Question 36

Osteoblasts and Osteoclasts

Answer 36

Osteoblasts build bone and Osteoclast chew bone.

Question 37

Endochondral ossification

Answer 37

responsible for the formation of most of the long bones in the body.

Question 38

Antagonistic pair

Answer 38

one relaxes, other contracts (Bicep and tricep)

Question 39

Synergistic

Answer 39

working together to accomplish the same function.

Question 40

Abductor

Answer 40

moves a part of the body away from the midline

Question 41

Adductor

Answer 41

moves a part of the body toward the midline