lecture 3 and 4 bones Flashcards
how many bones in body
206,
bones in axial skeleton and bones in appendicular skeleton
80 in axial and 126 in the appendicular
5 main roles of the skeletal system
> > Support: supports entire body,
Store minerals and lipids: The calcium salts stored in bone maintain normal concentrations of calcium and phosphate in blood
Produce blood cells: Red and white and platelets are made in red bone marrow,
Protection: the skeleton surrounds delicate organs and tissue
Leverage: bones function as levers that can change the magnitude and direction of force limbs generate
what are the 4 classes of bone
flat, long , short and irregular
describe and give example of long bone
elongated and slender has diaphysis and epiphysis. Are in things like arm, forearm, thigh, leg, fingers and toes. Femur is longest and heaviest bone of body
describe and give example of short bone
small and boxy, examples are carpals in wrist and tarsals in toes. usually filled with cancellous bone tissue
describe and give example of flat bone
are roughly parallel flat and thin, which allows for large surface area to attach muscles to. Examples are ribs, sternum, roof of skull and scapulae. compact bone outer and soft bone inner
describe and give example of irregular bone
have complex shapes that can be rounded, rough, short, notched or ridged. Several skull bones are irregular, so is vertebrae and pelvis bones
whats the axial skeleton
bones of the head, vertebral column and trunk. Roughly 40% of bones in body.
whats the appendicular skeleton
the bones of the upper and lower limbs
what are the skull bone
frontal bone, 2 parietal, an occipital and two temporal, then face bones
hand bone numbers
Carpals 8
Metacarpals 5
Phalanges 14 ( 3 on each except thumb)
foot bone numbers
T In tarsals means toes
Tarsals 7
Metatarsals 5
Phalanges 14 (2 big toe)
what are the bones in the pelvic girldle
two hip bones/ os coxae and the sacrum. coccyx is the bone at the bottom
what are pectoral girdle bones
clavicle and scapula
what percentage of bone is organic, what role does this part serve
33%, ts made of collagen, ground substance( proteoglycans) and its function is to resist tension
what percentage of bone is inorganic, what are the structures and what roles does it do?
The inorganic component makes up 67% of the rest of the bone matrix.
These inorganic parts is what makes bone so hard, these components are things like calcium and phosphate ions in the matrix. These make bone very resistant to compression.
where in the bone is red and white blood cells made
white and red in the Red bone marrow
who has more red marrow kids or adults, and why
Kids have lots of this red marrow as they are growing and need lots of red blood cells to do this, adults have much less as they no longer need to support growth.
what makes the ECM of bones
33% organic components
67% inorganic components inorganic as not made by cell itself
name the main mineral in inorganic bone ECM
hydroxyapatite
how much weight of bone mass does cellular component make
2%, 98% is ECM
where are Osteoclasts found
in the endosteum
why do we remove bone tissue
Allows body to mobilise calcium, phosphate and other
minerals from the bone matrix
there is no central canal blood vessels in cancellous bone tissue why
because the struts of trabeculae aren’t large eough and there’s not enough space between them
since no blood vessels, how does cancellous bone cells, osteocytes get nutrients
through diffusion of blood down the trabeculae, the diffused nutrients move down cancalaculi to the lacunae to these cells.
fibula with its organic component of ECM removed will
shatter/ be brittle
fibula with inorganic components removed
be soft, so able to compress and bend
difference of appendicular and axial skeleton
axial is the bones of the trunk. 80. the appendicular are the bones of the limbs with 126 bone
