Musculoskeletal System

Question 1

types of muscle

Answer 1

skeletal, smooth, and cardiac

Question 2

muscle type:
involved in support and movement, propulsion of blood in the venous system, and thermoregulation; appears striated, is under voluntary (somatic) control, is polynucleated, and can be divided into red (slow-twitch) fibers and white (fast-twitch) fibers

Answer 2

skeletal muscle

Question 3

skeletal muscle:

carry out oxidative phosphorylation

Answer 3

red (slow-twitch) fibers

Question 4

skeletal muscle:

rely on anaerobic metabolism

Answer 4

white (fast-twitch) fibers

Question 5

muscle type:
in the respiratory, reproductive, cardiovascular, and digestive systems; appears nonstriated, is under involuntary (autonomic) control, and is uninucleated; can display myogenic activity

Answer 5

smooth muscle

Question 6

contraction of muscle without neural input

Answer 6

myogenic activity

Question 7

muscle type:
comprises the contractile tissue of the heart; appears striated, is under involuntary (autonomic) control, and is uninucleated (sometimes binculeated); can display myogenic activity; cells are connected with intercalated discs that contain gap junctions

Answer 7

cardiac muscle

Question 8

cardiac muscle:
connections between the cytoplasm of adjacent cells, allowing for flow of ions directly between cells; allows for rapid and coordinated depolarization of muscle cells and efficient contraction of cardiac muscle

Answer 8

gap junctions

Question 9

Answer 9

Question 10

the basic contractile unit of striated muscle; made of thick (myosin) and thin (actin) filaments; can be divided into different lines, zones, and bands

Answer 10

sarcomere

Question 11

sarcomere:

are found on the thin (actin) filament and regulate actin-myosin interactions

Answer 11

troponin and tropomyosin

Question 12

sarcomere:

define the boundaries of each sarcomere

Answer 12

Z-lines

Question 13

sarcomere:

located in the middle of the sarcomere

Answer 13

M-line

Question 14

sarcomere:

contains only thin (actin) filaments

Answer 14

I-band

Question 15

sarcomere:

contains only thick (myosin) filaments

Answer 15

H-zone

Question 16

sarcomere:
contains the thick (myosin) filaments in their entirety; is the only part of the sarcomere that maintains a constant size during contraction

Answer 16

A-band

Question 17

formed by sarcomeres attached end-to-end

Answer 17

myofibrils

Question 18

a calcium-containing modified endoplasmic reticulum that surrounds a myofibril

Answer 18

sarcoplasmic reticulum (SR)

Question 19

muscle cells (muscle fibers) formed by many myofibrils

Answer 19

myocyte

Question 20

the cell membrane of a myocyte; has system of T-tubules connected to it that are oriented perpendicularly to the myofibrils, allowing the action potential to reach all parts of the muscle

Answer 20

sarcolemma

Question 21

the motor neuron releases acetylcholine in the neuromuscular junction that binds to receptors on the sarcolemma, causing depolarization

Answer 21

initiation of muscle contraction

Question 22

where muscle contraction begins

Answer 22

neuromuscular junction

Question 23

initiation of muscle contraction:

spreads down the sarcolemma to the T-tubules, triggering the release of calcium ions

Answer 23

depolarization

Question 24

initiation of muscle contraction:

bind to troponin, causing a shift in tropomyosin and exposure of the myosin-binding sites on the thin (actin) filament

Answer 24

calcium ions

Question 25

states that shortening of the sarcomere occurs as myosin heads bind to the exposed sites on actin, forming cross bridges and pulling the thin (actin) filament along the thick (myosin) filament, which results in contraction

Answer 25

sliding filament model (cross-bridge model)

Question 26

occurs when acetylcholine is degraded by acetylcholinesterase, terminating the signal and allowing calcium to be brought back into the sarcoplasmic reticulum (SR); ATP binds to the myosin head, allowing it to release from actin

Answer 26

muscle relaxation

Question 27

muscle cells exhibit an all-or-nothing response

Answer 27

simple twitch

Question 28

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

Answer 28

frequency summation

Question 29

simple twitches that occur so frequently as to not let the muscle relax at all, a more prolonged and stronger contraction

Answer 29

tetanus

Question 30

contained in muscle cells to reduce oxygen debt and forestall fatigue

Answer 30

additional energy reserves

Question 31

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

Answer 31

oxygen debt

Question 32

additional energy reserve: | can transfer a phosphate group to ADP, forming ATP

Answer 32

creatine phosphate

Question 33

additional energy reserve: | a heme-containing protein that is a muscular oxygen reserve

Answer 33

myoglobin

Question 34

can be divided into axial and appendicular

Answer 34

human skeletal system

Question 35

consist of bone in the midline such as the skull, vertebral column, rib cage, and hyoid bone

Answer 35

axial skeleton

Question 36

consists of the bones of the limbs, the pectoral girdle, and the pelvis

Answer 36

appendicular skeleton

Question 37

is derived from embryonic mesoderm and includes both compact and spongy (cancellous) types

Answer 37

bone

Question 38

bone: | provides strength and is dense

Answer 38

compact bone

Question 39

bone: | has a lattice-like structure consisting of bony spicules known as trabeculae; the cavities are filled with bone marrow

Answer 39

spongy (cancellous) bone

Question 40

bone: contain shafts called diaphyses that flare to form metaphyses and terminate in epiphyses which contain an epiphyseal (growth) plate that causes linear growth of the bone

Answer 40

long bones

Question 41

bone: | layer of connective tissue that surrounds bone

Answer 41

periosteum

Question 42

bone: | attach bones to muscles

Answer 42

tendons

Question 43

bone: | attach bones to each other

Answer 43

ligaments

Question 44

provides the strength of compact bone; contains both organic components (collagen, glycoproteins, and other peptides) and inorganic components (hydroxyapatite)

Answer 44

bone matrix

Question 45

bone matrix: | structural unit of bone; organized into concentric rings called lamellae around a central Haversion or Volkmann's canal

Answer 45

osteons (Haversian system)

Question 46

bone matrix: located between lamellar rings, contain osteoclasts, which are connected with canaliculi to allow for nutrient and waste transfer

Answer 46

lacunae

Question 47

carried out by osteoblasts and osteoclasts

Answer 47

bone remodeling

Question 48

bone remodeling: | build bone

Answer 48

osteoblasts

Question 49

bone remodeling: | resorb bone

Answer 49

osteoclasts

Question 50

bone remodeling: | increases resorption of bone, increasing calcium and phosphate concentrations in the blood

Answer 50

parathyroid hormone

Question 51

bone remodeling: | increases resorption of bone, leading to increased turnover and the production of stronger bone

Answer 51

vitamin D

Question 52

bone remodeling: | increases bone formation, decreasing calcium concentrations in the blood

Answer 52

calcitonin

Question 53

a firm, elastic material usually found in areas that require more flexibility or cushioning, is avascular and is not innervated (supplied with nerves)

Answer 53

cartilage

Question 54

secretes cartilage

Answer 54

chondrocytes

Question 55

matrix of cartilage

Answer 55

chondrin

Question 56

the hardening of cartilage into bone

Answer 56

endochondral ossification

Question 57

the transformation of undifferentiated embryonic connective tissue (mesenchyme) into bone; occurs in bones of the skull

Answer 57

intramembranous ossification

Question 58

may be classified as immovable or movable

Answer 58

joints

Question 59

joints: | are fused together to form sutures or similar fibrous joints

Answer 59

immovable joints

Question 60

joints: | are usually strengthened by ligaments and contain a synovial capsule

Answer 60

movable joints

Question 61

joints: | encloses the joint (articular) cavity

Answer 61

synovial capsule

Question 62

joints: | layer of soft tissue that secretes synovial fluid

Answer 62

synovium

Question 63

joints: | lubricates the movement of structures in the joint space, aids in motion

Answer 63

synovial fluid

Question 64

joints: | coats the articular surfaces of bones in the joint, aids in movement and provides cushioning

Answer 64

articular cartilage

Question 65

muscles that serve opposite functions; when one muscle contracts, the other lengthens; e.g. the biceps and triceps

Answer 65

antagonistic pairs

Question 66

muscles working together to accomplish the same function

Answer 66

synergistic

Question 67

protein that acts primarily as a protein motor, but also has secondary activity as an ATPase

Answer 67

myosin

Question 68

a disordered healing mechanism of unplanned cell death

Answer 68

necrosis

Question 69

vacant spaces in bone tissue that were formerly occupied by osteocytes; found in mature bone as a result of cell death in cavities that lack blood supply and nerves

Answer 69

lacunae

Question 70

contain capillaries and nerves, and osteocytes often form concentric circles around them

Answer 70

Haversian canals