bone, bone marrow, vessels and blood Flashcards
types of bone
long, short, flat, irregular and sesamoid
long bones and example of where they are found
longer than they are wide, found in the femur - support body weight and aid movement
short bone and example of where they are found
as long as they are wide, found in the wrist and ankle joints - provide stability
flat bones and example of where they are found
they are somewhat flat in shape and are found in the skull, thoracic cage (ribs) and pelvis - protect internal organs and large area for muscle attachment
irregular bones and example of where they are found
they don’t fit into any other category because they vary in shape. example is the spine - protect internal organs e.g vertebrae protect spinal chord
sesamoid bones and example of where they are found
small round bones found at tendons e.g patella of the knee - protect tendons from stress and damage.
what are the 2 types of bone found in a long bone
cancellous - spongy and filled with bone marrow in the middle
compact - external hard bone
make up and function of red marrow
rich blood supply found in spongey bone, replenish red blood cells in blood
make up and function of yellow marrow
full of adipocytes and poor blood supply. acts as shock absorber and energy source. can convert to red marrow
structure of cancellous spongey bone
each trabeculum consists of many osteocytes in lamellae like rings on an old tree. osteoblasts and osteoclast are on the outside and are able to remodel them. draw picture
how do mature cells leave the bone?
cells move into sinusoid capillaries which lead to the central marrow vein to take them out of bone.
how do platelets leave the bone
a megakaryocytic will bind to the sinusoid cell wall and release platelets into the lumen
what are the different types of vessel
continuous- no gaps
fenestrated- with fenestrations
sinusoid - an incomplete basement membrane
pathway which the newly forms red blood cells take after leaving the bone marrow
venule to vein to larger vein to vena cava. takes them 2 days to be activated
pathway which newly formed white blood cells take after leaving the bone marrow
same route as red blood cells but T cells need to be matured in the thymus. ( B cells were already matured in the bone marrow)
what is microcirculation/ precapillary sphincters
located between arterioles and capillaries they can contract to prevent the flow of blood into the capillaries. Controls fluid exchange between capillaries and tissues outside capillary bed
what is the structure of a vein
carries blood from body to the heart. 3 layer including:
1) tunica intima- endothelial cells
2)tunica media - elastic fibres and smooth muscle
3) tunica externa- elastic fibrous capsule
have large lumen, low pressure, run through large muscles and have valves to prevent back flow of blood
where does the vena cava lead to and where does the blood flow after that
the right atrium of the heart. Right = deoxygenated. then goes to lungs via pulmonary artery and back to left atrium and then around the body
types of veins
pulmonary- carry oxygenated blood to left atrium of heart
systematic - carry deoxygenated blood to heart
superficial- located near skins surface
deep- located deep near organs
structure of an artery
carry oxygenated blood away from the heart
1) tunica intima - elastic lining and smooth endothelium
2) tunica media - smooth muscle and elastic fibres. Much thicker than veins
3) tunica externa - strong outside capsule with elastin and collagen so allows them to stretch but prevents over expansion
artery vs vein
artery - thick walls, narrow lumen, no vales, lots of elastic and collagen to withstand pressure. High blood pressure resists back flow
vein - thin walls, wide lumen, valves to prevent back flow and wide lumen = less resistance for blood flow
function of collateral blood vessels
provide protection for tissues that become compromised by providing an alternate pathway
what is angiogenesis
production of new blood vessels from existing ones
what is vasculogenesis
formation of new blood vessels
