Muscular System

Question 1

Properties of Skeletal muscle

Answer 1

Support & movement, blood propulsion, thermoregulation, striated
• Voluntary (somatic) control
• Multinucelated

Can be red or white fibers

Question 2

Skeletal muscle red fibers

Answer 2

Slow twitch. Support (dark meat). Carry out oxidative

phosphorylation.

Question 3

White Fibers:

Skeletal muscle

Answer 3

Fast-twitch. Active (white meat). Anaerobic metabolism.

Question 4

Properties of smooth muscle, where is it found?

Answer 4

Respiratory, reproductive, cardiovascular, digestive
• Involuntary (autonomic) control
• Uninucleated
• Can display myogenic activity without neural input

Question 5

Properties of cardiac muscle?

Answer 5

Contractile tissue of the heart
• Involuntary (autonomic) control
• Uninucleated (sometimes binucleated)
• Can display myogenic activity
• Cells connected with intercalated discs that contain gap junctions

Question 6

Which germ layer is the skeletal system dervived from?

Answer 6

Mesoderm

Question 7

Axial Skeleton

Answer 7

Skull, vertebral column, ribcage, hyoid bone

Question 8

Appendicular Skeleton

Answer 8

Bones of limbs, pectoral girdle, pelvis.

Question 9

Bones of limbs, pectoral girdle, pelvis.

Answer 9

Lattice-like structure of bony spicules known as trabeculae.
Cavities filled with bone marrow

Question 10

Red bone marrow

Answer 10

Filled with hematopoietic stem cells

Question 11

yellow bone marrow

Answer 11

Yellow: fat

Question 12

Long Bones

Answer 12

Shafts called diaphysis that flare to form metaphyses and
that terminate in epiphyses. Epiphyses contain
epiphyseal (growth) plate.

Question 13

Periosteum:

Answer 13

Connective tissue that surrounds bone.

Question 14

Ligaments:

Answer 14

Attach bones to other bones

Question 15

Tendons

Answer 15

: Attach bones to muscles.

Question 16

Bone Matrix: Osteons

Answer 16

Osteons are the chief structural unit of compact bone,
consisting of concentric bone layers called lamellae, which
surround a long hollow passageway, the Haversian canal.
Between rings are lacunae, where osteocytes reside,
which are connected with cancaliculi.

Question 17

Osteoblasts

Answer 17

build bone

Question 18

Osteoclasts

Answer 18

Reabsorb bone

Question 19

What does parathyroid hormone release do to bone reabsorption and calcium levels?

Answer 19

Increases reabsorption of bone and increases blood calcium

Question 20

What effect does vitamin D have on bone reabsorption and blood calcium

Answer 20

Increase both

Question 21

What effect does calcitonin have on bone formation and calcium in the blood

Answer 21

Increases bone formation and decreases blood calcium concentration

Question 22

What secretes cartilage?

Answer 22

Chondrocytes

Question 23

Is cartilage innervated?

Answer 23

No

Question 24

Immovable joints

Answer 24

Fused together to form sutures

Question 25

Movable joints

Answer 25

Strengthened by ligaments and contain a synovial capsule

Question 26

Synovial fluid

Answer 26

Secreted by synovium and it lubricates joints

Question 27

Fetal bones

Answer 27

Bones form from cartilage through endochondroal
ossification. Skull bones form directly from mesenchyme
in intramembranous ossification.

Question 28

Sacromeres

Answer 28

Basic contractile unit of striated muscle

Question 29

Are myosin thick or thin?

Answer 29

Thick

Question 30

Are actin thick or think filaments?

Answer 30

Thin

Question 31

Where are troponin and tropomyosin found and what do they do?

Answer 31

Troponin & tropomyosin found on the thin filament and regulate actinmyosin interactions

Question 32

Z-lines:

Answer 32

Define the boundary of each sarcomere

Question 33

M-line

Answer 33

Middle of sarcomere

Question 34

o I-band:

Answer 34

Only actin filaments.

Question 35

H-zone:

Answer 35

Only myosin filaments.

Question 36

A-band

Answer 36

Contains both actin and myosin. Only part that

maintains a constant size during contraction.

Question 37

What happens to the z lines and the I bands as the sarcomere contracts?

Answer 37

Gets closer together

Question 38

What happens to the A band when the sarcomere contracts?

Answer 38

Stays the same

Question 39

Sarcoplasmic Reticulum:

Answer 39

Ca2+ filled modified endoplasmic reticulum.

Question 40

Sarcolemma:

Answer 40

Cell membrane of a myocyte

Question 41

T-tubules:

Answer 41

Connected to sarcolemma. Carry signals

Question 42

Describe the process of contraction and relaxation

Answer 42

Begins at neuromuscular junction, where the efferent neuron release
acetylcholine that binds to receptors on the sarcolemma, causing
depolarization
• Depolarization spreads down sarcolemma to T-tubules, triggering the
release of Ca2+
• Ca2+ binds to troponin, causing a shift in tropomyosin and exposure of
the myosin-binding sites on the actin filament
• Shortening of the sarcomere occurs as myosin heads bind to the
exposed sites on actin, forming cross bridges and pulling the actin
filament along the thick filament. “Sliding filament model”
• Muscles relax when acetylcholine is degraded by acetylcholinesterase,
terminating the signal and allowing Ca2+ to return to the SR.
• ATP binds to myosin head, allowing it to release form actin

Question 43

Simple Twitch:

Answer 43

: Single muscle fiber responds to brief stimulus.

Question 44

Frequency Summation:

Answer 44

Addition of multiple simple twitches before the

muscle has a chance to fully relax.

Question 45

Oxygen Debt:

Answer 45

Difference between O2 needed and O2 present.

Question 46

Creatine Phosphate:

Answer 46

Adds a phosphate group to ADP, forming ATP

Question 47

Myoglobin:

Answer 47

Heme-containing protein that is a muscular

oxygen reserve.