Question | Answer |
Osteo= | bone |
Function skeleton (6 things) | (1)support (2)Fat storage (3)protection (4)movement (5) ca&Phosphorus reserve (6)haemopoisis |
Fn (1)support | -structural framework
-tendons-attach muscle to bones |
Fn (2)fat storage | -yellow bone marrow |
Fn (6)haemopoisis | -red bone marrow
-producing blood |
Fn (4)Movement | -antagonistic muscles
-joints provide leavers
-amplified movement |
Fn (5)Ca & phosphorous reserves | -storage & release |
Fn (3) Protection | -hard
-cranial (brain)
-ribs (heart & lungs)
-pelvic (ovaries) |
Two main skeletal regions | (1)axial
(2)appendicular |
(1)axial | -ribcage, spine, cranium
-support/protection
-haemopoisis |
(2)appendicular | -outer limbs
-movement
-storage |
long bone
[Epiphysis] | -end of bone
-compression
-no periosteum
-thin outer cortex
-trabeculae(beams& rods of support)
-red bone marrow |
long bone
[Diaphysis) | -centre
-bending forces
-periosteum
-perforating sharpey's fibres
-yellow bone marrow |
perforating sharpey's fibres | -long bone
-diaphysis
-connect periosteum to compact bone |
Bone=specialised CT (made of) | -fibres -ground substance -cells |
Fibres (bone CT) | -collagen -resists tension(pulling) -organic |
Ground Substances (bone CT) | -Ca10(PO4)6OH2 -inorganic -compression & sqeezing |
Cells (bone CT) | OSTEO -genic -blast -cyte -clast |
Osteogenic | -from stem cells
-normally dormant
-surface of bone & canals |
Osteoblast | -syn,deposition & mineralisation of osteoids
-in layers under peri/endosteum |
Oestoid | -organic(mainly collagen) -other=proteoglycans & proteins -calcified -strong & dense -no diffusion |
Osteocyte | -mature bone -trapped in lacunae -communication through canaliculi -exchange nutrients & waste with blood |
Osteoclast | -bone destroying -fusion WBC progenitor cells -secrete acid & enzymes -location:bone reabsorption |
Order of bone cell development | osteogenic->osteoblast->osteocyte |
calcification | -forms oestoids -bone salt(hydroxyapatite) -nutrients can't diffuse freely -hard & dense |
Bone growth | -long bone grows in diameter -bone remodelling |
Appositional growth | -periosteum=active
-osteogenic->oesteoblasts=osteoids+osteocytes
-osteoblast->osteogenic/die -osteoids=fully calcified |
Bone reabsorption | -monocyte precursor from BV->osteoclast secret acids
-osteoclast apoptosis (short life) -BVin new space |
bone can't undergo _______ growth. WHY? | -interstitial -too rigid -only by adding to surface |
appositional growth & remodeling often occur _______ of one-another =? | independently -=bone remodeling |
long bone growing in length? | endochondral ossification |
Mature bone | -lamellar -osteoblasts in layers=lamellae
-collagen alternating 90* Win layer (Wstand F in all directions) |
Spongy bone | -trabecular -5x turnover than compact -lighter
-irregular lattice -outward growth -medullary cavity(bone marrow)
-inside -epiphysis support compact W multiple directional force
-calcunae radiate outwards
-BV for norishment |
Osteon formation in compact bone (2types) | (1)appositional growth of 1* osteon
(2)osteoclast activitiy of 2* osteon |
(1)appositional growth of osteon | -near surface -new bone formed -around existing BV
-osteoblast put down new bone forming ridges around BV
-concentric lamellae fill inwards
-bone grows outwards |
(2)osteoclast activity of 2* oesteon | -inside existing tissue
-bone needs remodeling
-'cutting core' through bone
-osteoblast line tunnel
-reduced to size of haversian canal |
Compact bone function & location | -strong & dense
-outer layer
-thicker exposed to large forces
-outershell
-diaphysis |
Compact bone growth & blood supply | -inwards of tunnel
-BV in haversian & volkmann's canals |
Spongy bone Function & location | -support outer cortex of compact
-F in lots direction
-rapid Ca & P turnover
-epiphysis
-inside |
spongey bone growth & blood supply | -outwards
-medullary cavity (bone marrow)
-02 & nutrients in |
Joints | -pt where bones interconnect
-movement
-force transition
-growth |
Synarthrosis | -immovable
-V stable
-axial |
Amphiarthosis | -slightly movable
-av. stability |
Diarthrosis | -freely movable
-low stability
-appendicular |
Simple synovial joint | -not restricted by properties of tissues holding ends of bones together
-end of bones=free (except articulate cartilage
-instability |
Synovial joint [4 common features] | -articulate capsule
-articulate cartilage
-synovial fluid
-joint cavity |
synovial joint [articulate cartilage] | -specialised hyaline
-thin layer at end of bones
-absorb shock
-support heavy loads
-near frictionless surface |
chondrocytes
(CELLS) | -syn. joint
-build, repair & maintain articulate cartilage
-in lacunae
-nests |
Extracellular matrix of articular cartilage [syn. joint] | -H2O & sol. ions
-Fibres
-gylcosamino/proteoglycans |
Fibre [articulate cartilage] | -EMC
-collagen
-'solid phase' fixed inside tissue
-zonation patterns |
water & soluble ions [articulate cartilage] | -ECM
-'fluid phase'=move in/out of tissue |
Gycosaminoglycans & proteglycans [articulate cartilage] | -ECM
-'solid phase'
-swelling & hydrating mech. |
Glycosaminoglycan | -repeating disacch. unit
-negative charge
-many attached to protein core=proteoglycan |
Proteoglycans | =many GAG attached to protein core
-charges repel
-bottle brush |
PG complex | -PG attached to hyaluronic acid chain
-join to collagen fibres |
[loading cycle] -ve charges.. | -attract ions -incr.[ion] -osmotic flow -swelling of cartilage |
[loading cycle] loaded equlibrium=? | -swelling F=tension F |
[loading cycle] load introduced | -water & ions forced out
-into joint space & syn. fluid |
synovial joint [articulate capsule] | -sleeve on ends of bone
-tight during extremes
-perforated W nerves & vessels
-ligaments reinforce |
Fibrous layer [articulate cartilage] | -outer dense CT
-interlacing collagen
-cont. W periosteum
-protections syn. mem. & joint
-poorly blood
-lots nerves |
synovial membrane [articulate capsule] | -inner loss CT
-intima(synoviocytes secret fluid)
-subintima
(lots BV,macrophages,fat,fibroblast=
maintainence & protection) |
synovial joint [Joint cavity] | -V small
-btwn. articulating surfaces
-mostly vili of syn. mem. in space |
synovial joint [synovial fluid] | -lubrication
-shock abs.
-chondrocyte met.
-joint maintenance
-from vessels in subitima & synoviocytes |
Muscle functions (6) | (1)convert ATP-->mech. E
(2)movement-of gut,bones,heart
(3)stability-joints,posture
(4)communication-writing, reading etc
(5)control openings & passages-sphincter,pupils
(6)heat production-85% |
Origin | -attachement moves least during contraction
(axial) |
insertion | -attachment moves most during contraction
(appendicular) |
osteotendinous junction | -OTJ
-tendon & bone |
myotendinous junction | -MTJ
-muscle & tendon |
Muscle belly | contractile part of muscle |
Muscle | bundle of fasicles |
epimysium | -dense irr. CT -surround entire muscle & peri |
perimysium | -dense irr. CT
-surround fasicles |
Fasicles | bundles of myocytes |
endomysium | -loose irr. CT -surrounding myocyte
-nerves & caps W supply myocytes |
Myocyte | -muscle fibre
-bundle of myofibrils |
sacroplasm | -area between myofibrils -glycogen & lipids |
sacrolemma | -cell mem. -rapid AP conduction |
myofibril | -many sacromeres |
Sacromere | -A, H band -Z disk |
A band | dArk |
I band | lIght |
Z-disk | closer during contraction |
muscle & attachement to CT | -epi/peri/endmysium blend -connect W CT-attaching to bone or muscle |
Deep fascia | -covers strutures of body
-dense reg. CT
-under skin & subcutaneous tissue |
Compartments | -muscles: supplied by same nerve,
similar function, grouped
-walls of fascia |
Hypertrophy | -incr muscle size (fibres)
-myocyte incr, diameter
-more myofibrils
-stim. steriods or repeated contraction |
anabolic steriods | -variants of testosterone
-incr. protein syn.
-bad side effects:acne,hairloss,infertility |
Atrophy | -decr. monocyte size
-muscle not used or been paralysed
-normally reversed |
Satellite cells | -lie beside muscle Win basement mem.
-repair damage to myocyte |
function of skeletal CT
[continuos epi/peri/endomysium] | -organisation(muscle construction)
-medium for BV&nerves(acess myocyte)
-prevent XS stretch
-distribute F |
Desmin | -hold adj. sacromeres
-align sacromeres=pull in unison |
Dystrophin | -protein forms bridge btw. myocyte & CT
-transmits F of contraction to endomysium |
muscular dystrophy | -disease -protein dystrophin transcribed properly/missing
-monocyte tears easily |