INTRO TO ANATOMY Flashcards
what is the function of the skeleton?
framework, protects internal organs, movement leverage, mineral storage + blood cell formation
what are the 2 divisions of the skeleton?
axial (80 bones e.g. skull, ribs, vertebrae, sternum) + appendicular (126 bones e.g. upper & lower limbs)
what are the 4 types of bones?
long, short, irregular, sesamoids
what are long bones?
tubular in shape, hollow centre, flexible e.g. femur, humerus, tibia, fibula, radius & ulna
what are short bones?
cuboidal in shape e.g. carpals & tarsals
what are irregular bones?
scapular & vertebrae
what are sesamoid bones?
forms within tendons- provides smooth surface to run over
what are angles on bones?
sharp bony angulations which may serve as bony or soft tissue attachments
what are bodies of bones?
largest part on bone- diaphysis/shaft
what are condyles on bones?
large prominence
what are crest on bones?
raised or prominent part of edge of bone- site where CT attaches muscle to bone e.g. iliac crest
what is the epicondyle on bones?
prominence that sits atop of a condyle
what is the facet of the bone?
smooth, flat surface that forms a joint with another flat bone or another facet forming a gliding joint
what is the fossa of a bone?
shallow depression in the bone surface
what is a groove on a bone?
a furrow in the bone surface which runs along the length of a vessel or nerve
what is the role of a notch of a bone?
provides stabilisation to an adjacent articulating bone- depression in a bone
what is a trochanter?
large prominence on the side of bones
what is a tuberosity on a bone?
moderate prominance where muscles & CT attach
what is a tubercle on a bone?
small rounded prominance where CT attaches
what is the anatomical position?
erect with feet shoulder width apart, head looking forward, hands at the side, palms facing forward
what is decubitus body position?
lying down
what is the supine position?
lying on back
what is prone position?
lying face down
what is lateral decubitus position?
lying on one side e.g. right lateral/left lateral
what is pronation?
turns the hands posteriorly e.g. back of hand
what is supination?
turns the hands anteriorly e.g. looking at palms of hands
what is flexion?
decreases angle of joint
what is extension?
increases angle of joint
what is opposition?
thumb brought to oppose another digit
what is elevation?
movement of scapular superiorly
what is depression?
move scapular inferiorly
what is eversion?
movement of foot sole away from median plane
what is inversion?
movement of foot sole towards the median plane
what is the buccal position of teeth?
anterior surface of tooth
what is the palatal position of teeth?
posterior surface of maxillary tooth
what is the lingual position of teeth?
posterior surface of mandibular tooth
what is bone made of?
bone matrix, mineral, cells
what does the bone matrix comprise of?
collagen & ground substance
what are the 3 bone cells?
osteoblasts, osteocytes, osteoclasts
what does the average compact bone contain?
30% matrix & 70% mineral
what is bone strength affected by?
direction of collagen fibres
how do the collagen fibres overlap?
form crosslinks with minerals deposited in space between fibrils
what give the bone the ability to flex without breaking?
collagen
what is the role of ground substance?
strenghthens bone by forming compression resistant networks between collagen fibrils
what is the role of bone minerals?
give bone strength
what is the bone mineral?
hydroxyapatite (HAP)- made up of calcium & phosphate
what compounds in bone matrix are transformed to HAP?
fluid Ca-P
how much HAP is located between & around collagen fibres?
90%
when does mineralisation occur?
when the local concentration of calcium & phosphorus is increased by action of ALP
what happens when the solubility of mineralisation is exceeded?
crystals form- initially amorphous calcium phosphate which tranform to HAP
what is the ratio of ca:p in hydroxyapatite?
between 1.3:1 and 2:1
what else does bone salts consist of?
Mg, Na, K & carbonate ions- not organised into specific crystals
how much HAP remains in an amorphorus form?
20-30% & are avaliable when extra Ca is needed in blood
when does HAP deposit abnormally in soft tissue?
dystrophic calcification (occurs in dying & dead tissue) + metastic calcification associated with hypercalcemia
what is the main role of hydroxyapatite?
provides compressional strength to the bone, and acts as a reserve of calcium that can be mobilised if blood calcium levels decrease.
what are osteoblasts?
bone forming cells- active near the bone surface
what do osteoblasts produce?
matrix (osteoid) the non mineralised matrix consisting of collagen & ground substance
what do osteoblasts become when production of matrix is complete?
becomes osteocytes
what are osteocytes?
cells located in lacunae within bony matrix- once osteoblasts- maintain bone
what is the role of osteocytes?
links with other osteocytes and osteoblasts- minerals move through channels & maintain bone structure
what is the role of osteoclasts?
remove bone during repair & remodelling- derived from macrophages & scavenge- create surfaces on which osteoblasts can function
what is cortical bone?
makes up hard outer shell of bone & shapes it- concentric ring structure with osteons
what does the cortical bone surround?
in long limbs, it surrounds the medullary cavity (site of bone marrow)
what spongy (cancellous) bone?
located within the bone at ends of long bone between the cortical bone & medullary cavity- large SA but less dense & stiff & provides strength to bone
how does cancellous bone provide strength to bone?
trabeculae follow lines of stress & can realign if direction of stress changes- contributes greatly to strength
what breaks down more easily- cortical or cancellous bone?
cancellous bone breaks down easily
what is woven bone?
collagen fibres are randomly arranged
what does woven bone contain?
many osteocytes- found at site of new bone formation, disorders & tumours- indicates a pathological process is occuring
what is lamellar bone?
collagen fibres are arranged in pattern- laid down on a preexisting framework e.g. woven bone
what is endochondral ossification?
method by which long bone grows
how do long bone bones develop from ossification?
3 centres: a diaphysis & 2 epiphysis
where does the lengthening of bone occur?
at ends of diaphysis where a layer of actively growing cartilage (growth plate) is located
what happens when the cartilage stops growing?
it ossifies, metaphysis closes & no further lengthening occurs
what does the intramembranous bone form?
bones of skull & face (flat bone)- formed by intramembraneous ossification
where does intramembraneous ossification occur?
in fibrous tissue but has a centre of ossification- extends from centre to periphery of bone
what are the 3 types of function joints?
synarthrosis, amphiarthrosis & diarthrosis
what are synarthrosis joints?
immovable joints e.g. skull
what are amphiarthrosis joints?
limited movement joints e.g. intervertebral disc
what are diarthrosis joints?
freely movable joint e.g. knee + elbow
what are the 3 primary classification system of joints?
fibrous, cartilaginous & synovial
what is the structure of a fibrous joint?
syndesmosis (held together by interosseous ligament, allowing movement) + suture (between bones in skull)
what is structure of a cartilaginous joint?
symphysis- characterised by borad, flattened disk of fibrocartilage between 2 bony surfaces
what is the structure of a synovial joint?
freely movable, fibrous capsule containing synovial fluid, exposed ends covered by articular cartilage, joints stabilised by ligaments
