skeletal system Flashcards
what are the 5 functions of the skeletal system
structural support protection of internal organs provides leverage for movement stores calcium produces blood cells
bone is a specialised form of what
connective tissue
cells are suspended in a matrix but what hardens the matrix
mineral salts
what is the name of the organic component found in bone
osteoid (collagen and protein)
strong and flexible
what is the name of the inorganic component of bone
Hydroxyapatite (calcium phosphate and calcium carbonate)
hard and relatively inflexible, brittle
what makes bones strong but flexible
combination of organic and inorganic compounds
how many types of bone cell are there
4
what do osteoblasts do
produce new bone
secrete osteoid (organic compound)
responsible for mineral deposition
what do osteocytes do
mature bone cells
located within lacunae (nests) within the bone
maintain the matrix (ensure well nourished)
what do osteoclasts do
remove mineral from the matrix
responsible for bone remodelling (break down bone a bit like phagocytes and free up mineral to use for plasma)
what do osteogenic stem cells do
found in periostem and endosteum. develop into osteoblasts (new bone)
what are the 2 types of bone tissue
compact bone (surface of bone) cancellous (spongy interior)
what is the name of the functional unit of compact bone
osteon (Haversian system) consists of haversian canal with artery running through it
are osteons aligned in the same or opposite direction
same to give the bone strength
what is callous bone made up of and how are they arranged
trabeculae - arranged haphazardly
what is in between trabeculae
bone marrow
draw and label long bone
draw it
what are the 2 types of bone marrow
red bone marrow (myeloid tissue - haemopoietic produces blood cells)
yellow bone marrow (fatty tissue that can onlybe stimulated to produce blood cells again in severe anaemia)
which age group has increased bone marrow
children as needed to grow as well as replace
what are the 4 shapes of bone and give an example of each
long (femur)
short (carpals)
flat (sternum)
irregular (vertebrae)
draw flat bone
draw it - NOT PRINTED!
what is the difference between intramembranous ossification and endochondral ossification
intramembranous ossification (no cartilage phase - flat bones and clavicles) endochondral ossification (cartilage phase - long, short and irregular bones)
how many stages are there for intramembranous ossification and what are they
3
1) mesenchymal cells secrete osteoid and later defrentiate into osteoblasts (which produce new bone) and the decomposition of calcium salts lead to calcification.
2) blood vessels grow into area to supply oxygen and nutrients
3) initially cancellous bone but later compact bone develops
how many stages are there for endochondral ossification and what are they
6
1) small areas of osteogenic cells (cartilage model laid down)
2) osteoblasts produce bone collar and blood supply develops
3) cells in diaphysis (shaft of long bone) differentiate into blastocysts - primary ossification centres
4) osteoclasts erode centre of diaphysis to create bone marrow cavity
5) secondary ossification centres develop in the epiphyses (the expanded articular end of a long bone) and epiphyses cartilage is replaced by bone
6) thin plates of cartilage remain at the metaphysis
what continues to be laid down during bone growth
new cartalidge at the epiphyseal side of epiphyseal plate (end of bones). As epiphysel plate narrows bone growth is reduced
for how long will the bone continue to grow
for as long as the rate of cartilage growth exceeds the rate of osteoblast activity as its the osteoblasts that replace the cartilage with bone
what 3 hormones increase bone growth at puberty
sex, growth and thyroid hormones
when are bones remodelled
as calcium salts are deposited and reabsorbed as required
bones are thickened to increase strength e.g back of head
old bone renewed and injured bone replaced
what is the symbol used for fracture/break
#
what are the 2 types of fracture
compound (open-goes through the skin)
simple (closed)
what are 6 classifications of break/fracture
greenstick (kids mostly, like broken green twig, stays together a bit) comminuted (fragments) linear (in line with direction of bone) transverse (across bone) oblique (diagonal across bone) spiral (twisted oblique)
how many stages are there to bone healing and how long does it take
4 stages, takes 8 weeks
what are the stages of bone healing
1) haematoma formation (blood clot forms around ends)
2) area invaded by capillaries, macrophages etc. soft callus forms
3) soft callus hardens by mineral deposition (bony callus)
4) remodelling of osteoclasts
what factors delay healing
inefficient blood supply tissue fragments between bone ends poor alignment of bone ends infection continued mobility of bone ends others (malnutrition, ageing etc)
what is the area where 2 bones meet called
a joint (articulation)
what are the 3 functional classifications of joints
synarthrosis - little or no movement e.g suture
ampiarthrosis - slightly moveable e.g intervertebral disc
diarthroses - freely moveable e.g hip
what are the 3 structural classifications of joints
cartilaginous - bones held together by cartilage e.g intervertebral disc
fibrous - bones held together by collagenous fibres e.g skull sutures
synovial - bones separated by a joint cavity and enclosed in a fibrous capsule e.g hip
what allows synovial joints to move more freely
synovial fluid
synovial joints are classified into 6 types, what are they
ball and socket (shoulder) hinge (elbow) gliding (between clavicle and sternum) pivot (atlantoaxial - shake head) ellipsoid (radiocarpal - wrist) saddle (thumb)
how many bones are there in axial skeleton
80 - skull, vertebral column and thorax (ribs)
what is the function of the skull
encase and protect the brain
what is the function of the vertebral column
supports the body
protects the spinal cord
name the sections of vertebrae from top to bottom and the number of vertebrae in each
cervical - 7 thorasic - 12 lumbar - 5 sacral - 5 (fused) coccyx - 4 (fused)
what is the job of the ribs
protect the contents of the thorax
how many pairs of ribs are there
12 all together
true - 7
false - 3
floating - 2
what are the 3 parts of the sternum from top to bottom (breastbone)
manubrium
body
xiphisternum
what does the appendicular skeleton consist of
(26 bones altogether) pectoral girdle upper limb pelvic girdle lower limb
what does the pectoral girdle consist of
scapulae and clavicles
what is the pectoral girdle responsible for
positioning of the shoulder and facilitating movement of the arm
what is the proper name for shoulder blade
scapula
what parts make up the shoulder
the scapula joins the head of humerus and the glenoid process (ball and socket joint)
what is another name for collar bone
clavicle
what is the upper limb made up of
arm, forearm, hand
what is the humerus
bone of the arm that finishes at the elbow
which parts of the humerus are commonly fractured
greater (outside) tubercle (shoulder end)
medial and lateral epicondyles (elbow end)
what are the 2 bones of the forearm
radius (bigger bone) and ulnar
what are key landmarks on the ulna
olecranon (pointy bit) head styloid process (wrist lump)
what are key landmarks on the radius
head
styloid process
what are the 3 different bones of the hand called from wrist to fingers
carpals, metacarpals and phalanges
what is the pelvic girdle made up of
sacrum and 2 os coxae
what are the names of the 3 bones that make up each os coxae and where do they fuse
ilium (sticky out bits) , ischium (under bum) and pubis (front) fuse at the acetabulum
what is the lower limb made up of
thigh, leg, foot
what are important landmarks of the femur
neck (next to head)
greater (outside) and lesser (inside) trochanters (either side of neck)
patella surface (knee end)
medial and lateral condyles (two lumps at end of femur)
what are the leg bones called
tibia (big) and fibula (small)
what are important landmarks of the tibia
medial and lateral tibial condyles (knee end) medial malleolus (ankle end)
what are the important landmarks of the fibula
head
lateral malleolus
what is the proper name for knee cap
patella
what kind of bone is the patella made up of
sesamoid bone (bone which is embedded within a tendon). it develops into quadriceps tendon
what are the names of the bones from the heel of the foot to the toes
talsals (heel)
metatarsals
phalanges (toes)
