Ch.35 Musculoskeletal Skeleton

Question 1

muscle

Answer 1

bundled contractile cells arranged in a parallel fashion that contract to cause directional movement

Question 2

skeleton

Answer 2

support structure required for movement

Question 3

types of skeleton

Answer 3

• hydrostatic skeleton (sea anemone)
• exoskeleton (chitin)
• endoskeleton (ribs)

Question 4

endoskeleton

Answer 4

internal framework that receives the force of muscles and supports and moves the body; found in vertebrates

• made up of bone and cartilage
• all vertebrates
• fins and limbs attached at pectoral and pelvic girdles

Question 5

*echinoderms

Answer 5

*have endoskeletons within their dermis consisting of ossicles

Question 6

types of bones (5 shapes)

Answer 6

• long
• short
• flat
• irregular
• sesamoid

Question 7

206 bones in the human body: two main types

Answer 7

• axial skeleton: bones of the skull, vertebral column, rib, sternum, and hyoid
• appendicular skeleton: bones of pectoral girdle, arms, hands and bones of pelvic girdle, legs, feet

Question 8

functions of bone

Answer 8

1. movement
2. support
3. protection
4. mineral storage
5. blood cell formation

Question 9

long bone structure

Answer 9

• compact
• spongey
• bone marrow

Question 10

compact bone structure

Answer 10

mature compact bone consist of many cylindrical Haversian system

Question 11

osteon

Answer 11

functional unit of the skeletal system

Question 12

bone marrow

Answer 12

yellow or red

Question 13

yellow bone marrow

Answer 13

• largely fat

- in the cavities of long adult bones

Question 14

red bone marrow

Answer 14

• produces red blood cells

- occurs in spongey bone of some bones

Question 15

bone formation and remodeling

Answer 15

in adults, bone building and breakdown occur constantly

• formation: embryo, fetus, newborn, adult
• remodeling adjusts bone strength and helps maintain blood calcium levels

Question 16

osteoblast

Answer 16

bone forming cell

Question 17

osteocyte

Answer 17

mature bone cell

Question 18

osteoclast

Answer 18

secrete enzymes that degrade bone

when osteoclast activity outpaces osteoblast activity: bone loss occurs

Question 19

embryo bone

Answer 19

cartilage model of future bone in the embryo

Question 20

fetus bone

Answer 20

blood vessel invades model; osteoblasts start producing bone tissue; marrow cavity forms

Question 21

newborn bone

Answer 21

remodeling and growth continue, secondary bone forming; center appears at knobby at of bone

Question 22

adult bone

Answer 22

mature bone

Question 23

bone density

Answer 23

measure of mineral composition of bone

-exercise can increase density

Question 24

osteoporosis

Answer 24

can decrease bone density

-may occur from osteoclast outpacing

Question 25

joints

Answer 25

areas of near contact between bones

Question 26

3 types of joints

Answer 26

- fibrous - synovial - cartilaginous

Question 27

fibrous joint

Answer 27

connected by short fibers (soft spot on skull)

Question 28

synovial joint

Answer 28

have ligaments that connect bones - knees and elbow (hinge joint) have flexion - may have bursae filled with fluid to lubricate joint - hip and shoulder (ball-socket)have rotational movement

Question 29

cartilaginous joint

Answer 29

cartilage allows slight movement (ribs, vertebral column)

Question 30

connective tissue in joints

Answer 30

- tendon: connects muscle to bone | - ligament: connects bone to bone

Question 31

types of join injuries

Answer 31

- strain - sprain - dislocation

Question 32

strain

Answer 32

tearing of muscle or tendon (normally results in swelling with bruising

Question 33

sprain

Answer 33

tear of ligaments (normally only swelling, no bruising) *ligaments are avascular*

Question 34

dislocation

Answer 34

separation at joint

Question 35

arthitis

Answer 35

(degenerative disorder w/ joint inflammation) - osteoarthritis: cartilage ends of bone wear off due to overuse, genetics - rheumatoid arthritis: synovial joint membranes inflame and thicken

Question 36

3 types of muscle

Answer 36

-skeletal, cardiac, smooth

Question 37

skeletal muscle structure

Answer 37

- muscle made up of muscle cells - muscle cells made up muscle fiber - each bundle of muscle fibers contain many myofibrils - within myofibril is the sarcomere

Question 38

neuromuscular junction

Answer 38

where a motor neuron synapsis with a muscle cell

Question 39

sarcoplasmic reticulum

Answer 39

where the calcium is stored and released

Question 40

active movement of sarcoplasmic reticulum

Answer 40

arrival of neuron impulses causes calcium to flow out to initiate muscular contraction which causes active movement

Question 41

relax movement of sarcoplasmic reticulum

Answer 41

relax action of muscle; resting state for muscle

Question 42

microfilaments in the sarcomere

Answer 42

- actin (thin): like two strands of beads twisted together | - myosin (thick): each myosin molecule has a tail and a double head

Question 43

sliding filament theory/ ratchet theory

Answer 43

actin fibers cross over myosin fibers to cause contraction

Question 44

sliding filament model:

Answer 44

-myosin head attaches to actin fibers -myosin heads tilt toward center, pulling actin inwards -even though actin slides; myosin does the work -actin and myosin fibers same the same length ( ONLY the sarcomere gets shorter during a contraction) -relax fibers move back

Question 45

troponin

Answer 45

calcium regulator | -slides past myosin causing muscle shortening, attached to tropmyosin

Question 46

tropomyosin

Answer 46

regulates actin-myosin interaction in muscle and non-muscle cells -blocks myosin binding sites on actin molecules, preventing cross-bridge formation that prevents muscle contraction

Question 47

two types of contraction

Answer 47

- isotonic contraction: movement, contracted muscle shortens | - isometric contraction: force, no movement, contracted muscle doesn't shorten