Structure and Function of the Musculoskeletal System

Question 1

the musculoskeletal system is composed of two systems that allow for mobility, what are those systems

Answer 1

• skeleton: bones and joints
• soft tissues: muscles, ligaments, tendons

Question 2

movement is accomplished by the _____ of the skeletal muscles and _____ at the joints

Answer 2

contraction; rotation

Question 3

name three functions of the skeletal system

Answer 3

• movement, supporting tissues, protection of vital organs
• site of blood cell formation (bone marrow)
• central to mineral homeostasis (bones store minerals)

Question 4

name five components of bone tissue

Answer 4

• osteoblasts
• osteocytes
• osteoclasts
• collagen fibers
• crystallized minerals

Question 5

______ are bone forming

Answer 5

osteoblasts

(bone is shaped according to its function)

Question 6

osteoblasts become ____ that are imbedded in bone

Answer 6

osteocytes

Question 7

____ are responsible for bone maintenance

Answer 7

osteocytes

Question 8

osteocytes help maintain bone by doing what

Answer 8

signaling osteoblasts and osteoclasts to form and resorb bone

(respond to parathyroid hormone)

Question 9

_____ are responsible for bone resorption/breakdown elements for transport by bloodstream

Answer 9

osteoclasts

Question 10

osteoclasts are large, multinucleated cells containing what

Answer 10

lysosomes filled with hydrolytic enzymes

(lysosomes break stuff down)

Question 11

_______ gives bone its tensile strength to hold itself together

Answer 11

collagen fibers

(developed from osteoblasts and are essential for bone strength)

Question 12

collagen fibers anchor _____ to the underlying bone

Answer 12

articular cartilage

Question 13

______ provide rigidity once mineralization occurs

Answer 13

crystallized minerals

Question 14

___ bone is 85% of skeleton; solid and extremely strong

Answer 14

compact bone

Question 15

compact bone is built upon the _____ system

Answer 15

haversian system

Question 16

what does the haversian system consist of

Answer 16

haversian canal, lamellae, lacunae, osteocyte, canaliculi

Question 17

________ bone is filled with red bone marrow (15% of skeleton)

Answer 17

spongy bone

Question 18

spongy bone lacks the haversian system but have ______

Answer 18

trabeculae (plates or bars)

Question 19

trabeculae maintain what

Answer 19

structure and function

Question 19

_______: double-layered connective tissue covering all bones

Answer 19

periosteum

Question 20

the _______ in the outer layer of the periosteum allows blood vessels to penetrate to inner bone

Answer 20

volkmann canals

(feeds bone tissue)
(blood supply to the bones isn’t a lot)

Question 20

the _____ layer of the periosteum contains blood vessels and nerves

Answer 20

outer

Question 21

the inner layer of the periosteum uses _____ to hold tendons and ligaments to bones

Answer 21

collagenous fibers

Question 22

name the four types of bones in the skeletal system

Answer 22

long, flat, short, irregular

Question 23

______: medullary cavity that contains fat (yellow marrow) in long bones

Answer 23

diaphysis

Question 24

____________= medullary cavity that contains fat (red marrow)

Answer 24

metaphysis

Question 25

____: known as "growth plate" allowing for growing bone length

Answer 25

epiphyseal plate (before puberty)

Question 26

______: epiphyseal plate calcifies and merges diaphysis and metaphysis (no more growth)

Answer 26

epiphyseal line (after puberty)

Question 27

_____ lines the medullary cavities of long bones

Answer 27

endosteum

Question 28

flat, short, and irregular bones consist of what type of bone

Answer 28

spongy bone that is surrounded by compact bone

Question 29

________: repair of microscopic injuries and maintenance of bone integrity

Answer 29

remodeling

Question 30

what are the three phases of remodeling

Answer 30

1. inflammatory phase (activation of the remodeling phase; 3-4 days) 2. repair phase (lasts a few days) 3. resorption/remodeling (4-6 months; bone returns to original size, shape, strength)

Question 31

in the inflammatory phase of remodeling, what forms

Answer 31

hematoma (provides nutrients)

Question 32

in the repair phase of remodeling what is formed

Answer 32

callus (begins phases of repairing injury)

Question 33

_____: sites where two or more bones meet allowing stability and movement

Answer 33

joints

Question 34

classification of bones is based on _______

Answer 34

movement

Question 35

________ is an immovable joint that is often fibrous

Answer 35

synarthrosis (ex. skull)

Question 36

________ is a slightly movable joint that is usually cartilaginous

Answer 36

amphiarthrosis (ex. symphysis pubis; moves with childbirth)

Question 37

____ is a freely movable joint that is usually synovial

Answer 37

diarthrosis (ex. knees, elbows, shoulders)

Question 37

_____ are the most movable and complex joints

Answer 37

synovial

Question 38

what are the four main components of synovial joints

Answer 38

- joint capsule/cavity - articular cartilage - synovial membrane - synovial fluid

Question 39

______ covers bony surfaces of synovial joints, reduces friction during movement

Answer 39

articular cartilage

Question 40

articular cartilage has no _____ (3)

Answer 40

blood vessels, lymph vessels, nerves

Question 41

articular cartilage is **insensitive to pain** and regenerates ________ after injury

Answer 41

slowly

Question 42

_________ lines the inner surface of the joint capsule

Answer 42

synovial membranes

Question 43

______ fills the joint cavity and lubricates the joint surface

Answer 43

synovial fluid (lubricates and nourishes joint surfaces)

Question 44

synovial fluid contains _______ fluid

Answer 44

superfiltrated blood plasma fluid

Question 45

synovial fluid contains _____ that phagocytize joint debris and microorganisms

Answer 45

leukocytes

Question 46

______: bundles of muscle fibers

Answer 46

fascicles

Question 47

________: outermost fascicle layer & forms tendons

Answer 47

epimysium

Question 48

_____: middle fascicle layer

Answer 48

perimysium

Question 49

_______: inner fascicle layer that surrounds muscle fascicles

Answer 49

endomysium

Question 50

______: fibrous tissue connecting muscle to bone

Answer 50

tendon

Question 51

_______: contractile units of muscles fibers

Answer 51

sarcomeres (functional unit of the neuromuscular system)

Question 52

sarcomeres act as a single entity, contracts as a whole from stimuli; "______" response

Answer 52

all-or-nothing

Question 53

skeletal muscle is _____ movement

Answer 53

voluntary

Question 54

skeletal muscle is striated and extrafusal; what does extrafusal mean

Answer 54

generate movement and provide muscle mass development

Question 55

______: motor units per muscle

Answer 55

innervation ratio

Question 56

_______ innervation ratios: prevent fatigue and have higher endurance of muscles

Answer 56

higher

Question 57

lower innervation rations facilitate ________ and fatigue ____ than higher innervation ratios

Answer 57

precision movement; easier/faster

Question 58

________: primary ion channels that control calcium release in muscles

Answer 58

ryanodine receptors (RyRs)

Question 59

RyR1

Answer 59

skeletal muscle

Question 60

RyR2

Answer 60

cardiac muscle

Question 61

RyR3

Answer 61

diaphragm, smooth muscle, brain

Question 62

name the four phases of contractions

Answer 62

- excitation (stimuli/nerve impulse) - coupling (building of myosin) - contraction (motor fibers full = movement) (All-or-Nothing) - relaxation (uncoupling and return to resting position)

Question 63

______: amount of oxygen needed to convert lactic acid waste to glucose and replenish fuels

Answer 63

oxygen debt

Question 64

what two things fuel muscle contraction

Answer 64

ATP, phosphocreatine

Question 65

isometric contraction

Answer 65

- Static or holding contraction - Muscle maintains a constant length as tension is increased - Muscle contracts, but the limb does not move

Question 66

isotonic (dynamic) muscle contraction

Answer 66

- Lengthening (eccentric) or shortening (concentric) contraction - Muscle maintains a constant tension as it moves - Muscle contracts and the limb moves

Question 67

______ muscle: prime mover (contraction)

Answer 67

agonist muscle

Question 68

_____ muscle: opposite of mover (relaxation)

Answer 68

antagonist muscle

Question 69

main test for bone function

Answer 69

serum calcium and phosphorus (also fo gait analysis or imaging studies)

Question 70

name three tests of joint function

Answer 70

- arthrography - arthroscopy - synovial fluid analysis

Question 71

_____ is a test of muscular function because it is increased when muscles are damaged

Answer 71

serum creatine kinase

Question 72

_________: occurs with acute muscle damage

Answer 72

myoglobinuria

Question 73

______: age-related loss of muscles

Answer 73

sarcopenia