Exam #5- Musculoskeletal Physiology

Question 1

osteoblasts

Answer 1

bone FORMING cells

bone MAKERS

become osteocytes that are imbedded in bone

form new bone and synthesize osteoid (un-mineralized portion of bone matrix that becomes mature bone)

the formation of new bone

Question 2

osteoclasts

Answer 2

bone RESORBING

bone BREAKERS

they’re attached to itegrins by podosomes- which helps bind to bone

secretes HCl and protease enzyme which leads to the resorption of bone (dissolves bone minerals and collagenase)

they “rest” when they’re not resorbing

bone resorption

Question 3

osteocytes

Answer 3

bone MAINTAINING

these coordinate osteoblast and clast function

they respond to PTH

bone maintenace

Question 4

compact bone

Answer 4

“cortical bone”

the main part of skeleton

solid and strong

consists of HAVERSIAN SYSTEM (structural unit)

surrounds spongy bone

Question 5

spongy bone

Answer 5

“cancellous bone”

filled with RED marrow

no haversian system

TRABECULAE: plates or bars instead

EPIPHYSIS= RED marrow

found in the long bones and surrounded by compact bone

Question 6

diaphsysis

Answer 6

contains yellow marrow

Question 7

what is the importance of the bone element, ground substance?

Answer 7

diffusion of substances between the bond and blood vessels

Question 8

which part of the bone contains the yellow marrow?

Answer 8

diaphysis

Question 9

bone healing

Answer 9

it heals itself

Question 10

bone remodeling

Answer 10

periosteal and endosteal surfaces are remodeled to size/shape of bone before injury

Question 11

phases of bone remodeling

Answer 11

activation, resorption, formation of new bone (aka secondary bone)- 3-4 months

resting, resorption (osteoclast), reversal (macrophage), formation (osteoblast), mineralization (lining cell, osteocytes)

hematoma forms, fibrocartilage callus forms, bone callus forms, bone remodeling occurs

Question 12

what is the final step in formation of bone?

Answer 12

mineralization

Question 13

movement based joint classifaction

Answer 13

synarthrosis- immovable

amphiarthrosis- slightly movable (amphi=both)

diarthrosis- freely movable

Question 14

what type of joint is classified as immovable?

Answer 14

synarthrosis

Question 15

structure based classification of joints

Answer 15

fibrous

cartilaginous

synovial

Question 16

fibrous joints

Answer 16

bone to bone

ex: sutures in skill

directly connected to bone by dense fibrous connective tissue

Question 17

cartilaginous joints

Answer 17

connected by fibrocartilage or hyaline cartilage

symphysis

synchondrosis

Question 18

symphysis joint

Answer 18

symphysis pubis and intervertebral disks

bones are connected by PAD/DISK of fibrocartilage

Question 19

synchrondrosis joint

Answer 19

joints between ribs and sternum

bones are connected by HYALINE cartilage (COSTAL cartilage)

Question 20

synovial joint

Answer 20

moveable, complex, diarthrosis (synovial fluid-lubrication/moveable)

Question 21

articular cartilage

Answer 21

REDUCES FRICTION in joint and distributes forces of WEIGHT BEARING

has NO blood vessels, lymph vessels, or nerves

insensitive to pain and regenerates SLOWLY after injury

Question 22

each muscle fiber is what?

Answer 22

a single muscle cell surrounded by a membrane that can excite/send an impulse

Question 23

myofibrils

Answer 23

functional unit of contraction

Question 24

white muscle

Answer 24

type II fibers

FAST

Question 25

red muscle

Answer 25

type I fibers sloooowwww

Question 26

muscle membrane

Answer 26

sarcolemma- spreads impulse basement membrane- keeps cell's shape

Question 27

ryanodine receptors (RyRs)

Answer 27

the primary ion channels that control Ca2+ release in muscles

Question 28

phases of muscle contraction

Answer 28

excitation coupling contraction relaxation

Question 29

excitation phase of muscle contraction

Answer 29

AP travels from nerve terminal to the NMJ this initiates an electrical impulse (muscle fiber AP) this triggers receptors in t-tubule wall which opens RyR channels and calcium release

Question 30

coupling phase of muscle contraction

Answer 30

calcium is released so now actin can bind w/myosin

Question 31

contraction phase of muscle contraction

Answer 31

actin slides toward myosin to form cross-bridge which leads to muscle shortening "all or nothing"

Question 32

relaxation phase of muscle contraction

Answer 32

cross-bridge detaches sarcomere lengthens as calcium pumps back into SR

Question 33

isometric

Answer 33

static/holding contraction muscle maintains a constant length as tension increases muscle contract, limb does not move

Question 34

isotonic movement

Answer 34

lengthening (eccentric) or shortening (concentric) contraction muscle maintains constant tension as it moves muscle contracts, limb moves

Question 35

agonist

Answer 35

prime mover CONTRACTS

Question 36

antagonist

Answer 36

reciprocal muscle RELAXES

Question 37

ligaments

Answer 37

attach bone to bone

Question 38

tendons

Answer 38

attaches muscle to bone

Question 39

aging of bones

Answer 39

loss of bone, stiff, brittle, decreases strength, lengthened bone remodel time, slow mineralization, osteoporosis, increased bone resorption

Question 40

aging of joints

Answer 40

cartilage is more rigid/fragile, ROM is decreased

Question 41

aging of muscles

Answer 41

apoptosis, sarcopenia (age-related loss of muscles), decreased strength and bulk, decreased O2 intake, decreased basal metabolic rate and lean body mass

Question 42

aging with exercise

Answer 42

improves muscle strength, increased bone mineral density, improves balance, coordination, mobility, and lean body mass decreases risk for falls