Ch 6: Musculoskeletal System

Front 1

skeleton arises from

Back 1

mesoderm

Front 2

two types skeleton

Back 2

exoskeleton: cover outside of organism like anthropods
endoskeleton: in side like humans ie vertabrates
exo good since protects outside and inside better major drawback is need to shed exo but dont in endo

Front 3

skeleton divided into (2)

Back 3

axial: skull vertabrae ribcage its the framework
appendicular: all other parts attaching to axial for stability

Front 4

2 main components of skeleton

Back 4

bone, cartilage both made of CT

Front 5

cartilage

Back 5

-flexible/softer than bone
-made of chondrin-->firm/elastic matrix (made by chondrocytes) and connective tissue
-find lots in fetus in pre/postnatal development turns/calcifies into bone
-in adult find in places need flexibility ie ears, nose, joints, larynx/trachea walls
-degradation-->arthritis since bones rub
-avascular (without blood/lymph vessels)

Front 6

compact bone vs spongy (cancellous) bone

Back 6

compact:strong compact
spongy: consists of trabeculae (bony spicules) , looks like sponge

Front 7

trabeculae cavities filled with

Back 7

bone marrow-->red or yellow
red: hematopoeitic stem cells generate all cells in blood
yellow: made of fat and pretty inactive

Front 8

appendicular made of___bones what are their characterisitics

Back 8

-long
-diaphyses=shaft
-epiphysis=rounded ends
-periphery of both surrounded by compact bone
-long bone diaphyses: bone marrow inside
-long bone epiphyses: spongy inside
-peritoneum= fibrous sheath surrounding long bone also for muscle attachment, need for growth/repair, some cells can become bone forming cells

Front 9

epiphyseal plate

Back 9

-separates epiphysis and diaphysis
-cartilaginous
-site of longitudinal growth

Front 10

bone structure:
-compact bone strength from _____made of 2 parts__&___
-describe them
-osteon, haversian canal, lamellae, lacunae, canaliculi

Back 10

-bone matrix, organic and inorganic compounds
-organic: collagen, glycoproteins, peptides
inorganic: calcium, phosphate, hydroxide
*minerals also found in bone like Na, Mg, K
-structural unit of bone encircles canal, blood vessels/nerves/lymph for bone, surround canal, spaced in matrix have osteocytes (bone maintenance), link lacunae for exchange nutrients/waste between canal and canaliculi

Front 11

bone formation (ossification)

Back 11

-two types
1) endochondral: cartilage-->bone most long bones made this way
2)intramembranous: undifferentiated embryonic CT ie mesenchymal tissue-->bone

Front 12

bone remodelling via (2) cells and (2) hormones and (1) vitamin

Back 12

-osteoblasts: build
-osteoclast: resorb/breakdown
both help maintain bone
when reforming material comes from blood, when breaking material released into blood ie cycle
remodelling affected by use/exercise ie use it or lose it
-parathyroid, calcitonin
-D

Front 13

joints

Back 13

-made of connective tissue
-2 types
1)movable: allow bones to move, strengthened by ligaments (connect bone to bone) and synovial cap (encloses joint cavity) . use synovial fluid/articular cartilage
2)immovable: ex)skull, dont move,

Front 14

skeletal muscle innervated by

Back 14

somatic NS

Front 15

basic unit of muscle=_____these put together end to end get___

Back 15

sarcomere, myofibrils

Front 16

myofibrils covered by____outside from this have___,
*cell membrane called

Back 16

-sarcoplasmic reticulum (lots of calcium)
-sarcoplasm
-sarcolemma-->generates AP, T-tubules connect to it and orient perpendicular to myofibrils to allow ion flow

Front 17

many myofibrils in a

Back 17

myocyte
*mutinucleated due to fusion

Front 18

why skeletal muscle look striated

Back 18

z line alignment and density of them

Front 19

skeletal muscle made of (2) fibers

Back 19

red: slow twitch, HIGH myoglobin, get energy AEROBIC
white: fast twitch, ANAEROBIC, LESS myoglobin
*red mitochondria rich, white mito poor (dont use electron transport chain)
*white easier to tire, but contract quicker

Front 20

myoglobin vs hemoglobin

Back 20

-myoglobin higher oxygen affinity
-myoglobin single polypeptide chain

Front 21

sarcomere structure:
made of thin and thick filaments what are they made up of
Z lines
M line
I band
H zone
A band
During contraction what happens to above lengths

Back 21

-thick: myosin
-thin: actin, tropomyosin, troponin
-boundaries of sarcomere
-runs down centre of sarcomere
-region of only thin filaments
-region of only thick filaments
-region of all the thick filament length (which will include some thin in it)
- H,I and distance between Z lines get smaller, A band size remain CONSTANT

Front 22

3 steps of contraction

Back 22

1) initiation: send signal via motor neuron,motor neuron--> nerve terminal (bouton)-->neurotransmitter into synapse and binds to muscle receptors=contraction. If enough acetylcholine binding=depolarized ie AP generated=increase sarcolemma permeability
2) sarcomere shortening: AP cause release of calcium from SR. calcium bind troponin-->tropomyosin to shift--> exposes myosin binding site on actin-->myosin binds--> myosin pulls on actin-->draws thin filaments to center of H zone--> shortens sarcomere
*ATPase activity in myosin for stroke and for removal of myosin from actin
*myosin resets by binding ATP
3) relaxation: no more SR stimulation=decrease calcium--> tropomyosin cover binding sites therefore no more contraction

Front 23

ATP needed for both contraction and release of muscle fibers true or false

Back 23

true, rigor mortis due to loss of ATP during death and so muscles rigid since no ATP to release

Front 24

how stimulation coupled to muscle response

Back 24

-stimulus intensity:
-simple twitch
-summation and tetanus

Front 25

stimulus intensity :
muscles show___response
tonus =

Back 25

-all or none, this response strength cant be adjusted, instead muscle control force by # fibers recruited
-muscles in constant state of low level contraction for both voluntary/involuntary

Front 26

simple twitch

Back 26

-response of 1 fiber to brief stimulation at or above threshold, 3 periods; latent, contraction, relaxation

Front 27

latent period

Back 27

-time between reaching threshold and onset of contraction -when AP spreads and release calcium,

Front 28

refractory period

Back 28

-after latent
-muscle unresponsive to stimulus
-2 types
1) absolute: no amount stimulus will make response since restoring resting potential
2) relative: higher than normal needed to get response

Front 29

summation and tetanus

Back 29

-freq summation= prolonged/frequent exposure cause not enough time to relax, contractions combine= stronger/longer
-tetanus= contractions so frequent no time to relax, stronger than simple twitch, prolonged tetanus=fatigue

Front 30

why muscle fibers contract all or none

Back 30

innervated by neurons who signal is AP which is all or none

Front 31

smooth muscle

Back 31

-non striated
-involuntary
-ANS innervates it
-one nucleus/cell
-calcium for contraction
-smooth continuous contraction
-longer more sustained contraction
*will respond to nervous input DOES NOT need external signals to contract= MYOGENIC ACTIVITY (can contract with no NS input)

Front 32

cardiac muscle

Back 32

-striated
-involuntary
-ANS innervation
-1-2 nuclei/cell
-calcium for contraction
-may have myogenic activity

Front 33

muscles need energy can use fats, glycogen and glucose also have (2) rother energy reserves

Back 33

1) creatine+ATP<-->creatine phosphate+ADP, do reverse when need quick supply of atp
2) myoglobin: binds oxygen more than hemoglobin, when oxygen used during muscle use myoglobin releases oxygen to keep aerobic going
*exhausted reserves then get ferment of left pyruvate to get NAD and start glycolysis again

Front 34

loose connective tissue

Back 34

-attach epithelium to underlying tissues
-3 protein fibers
1)collagenous: collagen, strong
2)elastic: elastin, give resilience
3)reticular: branched, connect CT to tissue
-2 cell types
1)fibroblasts (make stuff for extracell fibers)
2)macrophages

Front 35

dense CT

Back 35

-high conc of collagenous fiber
-forms tendons (muscle to bone) and ligaments (bone to bone thru joints)

Front 36

muscle bone interaction:
-muscle end attached to stationary bone=
-muscle end attached to moving bone=

Back 36

-origin, ie proximal end in limbs
-insertion, ie distal end in limbs

Front 37

muscles antagonistic in that

Back 37

one contracts while other lengthens

Front 38

synergistic muscles

Back 38

-helps principle muscles during movement

Front 39

flexor=
extensor=
abductor=
adductor=

Back 39

-contracts-->decrease angle of joint
-contract--> straighten joint
-move part of body AWAY from midline
-move part of body TOWARD midline