exam 3 blood and blood vessels Flashcards
what is the ground substance of blood
plasma
what are the 3 things that make up blood
erythrocytes (red blood cells)
leukocytes (white blood cells)
platelets (thrombocytes)
what are the functions of blood
transportation -oxygen/carbon dioxide -nutrients -waste products -hormones regulation -temp -pH -fluid levels protection
blood composition
plasma ~55% (water, proteins, solutes)
buffy coat < 1% (platelets, leukocytes)
erythrocytes
function and characteristics of eythrocytes
function: transport oxygen to cells and carbon dioxide away from cells
- shaped like biconcave discs
- anucleated
- filled with hemoglobin
function and size of leukocytes
larger than erythrocytes
function: help the body fight against disease
list the leukocytes in order of prominence
neutrophil lymphocytes monocyte eoeinophil basophil
characteristics and function of neutrophils
- most numerous type
- cytoplasm has fine pale granules
- nucleus is multi-lobed
function: phagocytize pathogens, esp bacteria
characteristics of lymphocytes
- cytoplasm lacks granules
- contain large, round dark purple nucleus
- thin ring of pale blue cytoplasm
- most located in lymphatic tissues
functions of the different types of lymphocytes
T-lymphocytes: coordinate immune activity
b-lymphocytes: produce antibodies
Natural killer cells: attack pathogens and abnormal cells
characteristics and function of monocytes
- largest leukocytes
- cytoplasm lacks (visible) granules
- pale blue cytoplasm
- C-shaped nucleus
- few in blood bc go to other organs
function: phagocytize pathogens, cellular debris, dead cells
characteristics and function of eosinophils
- cytoplasm contains prominent granules that stain reddish
- nucleus is bi-lobed
function: phagocytize allergens and destroy parasitic worms
characteristics and function of basophil
- makes up less than 1% of all leukocytes
- cytoplasm contains big granules that stain blue/purple
- bilobed nucleus
function: release histamine and heparin during inflammatory or allergic reactions
characteristics and function of platelets
function: assist with blood clotting if there is a hole in the vessel
- cytoplasmic fragments from a larger cell
- anucleate
- very small
function of arteries
take blood away from the heart to other tissues
- transport blood high in oxygen
- relatively thick, springy wall
- blood pressure higher in arteries than in veins
what is the exception of blood flow direction of arteries and veins
pulmonary arteries and veins
function of veins
take blood back to the heart
- transport blood low in oxygen and high in carbon dioxide
- walls are much thinner and collapsible
- lumen generally larger than arteries
- lower blood pressure
function of capillaries
- connect arteries and veins
- gas/nutrient exchange occurs here
describe the pathway of blood
heart –> elastic arteries –> muscular arteries –> arterioles –> capillaries –> venules –> veins –> heart
what are the layers of blood vessels from most superficial to deep
tunica externa
tunica media
tunica intima
describe tunica media
- circularly arranged smooth muscle fibers
- largest layer in arteries
- sympathetic innervation typically causes vasoconstriction
describe tunica externa
- areolar CT
- largest layer in veins
describe tunica intima
- endothelium (simple squamous epithelium)
- areolar CT
- always very thin
describe elastic arteries
vessel wall contains large amounts of elastic protein fibers
describe muscular arteries
less elastic fibers, more smooth muscle in the tunica media
describe arterioles
- tunic media contains 6 or fewer layers of smooth muscle
- smallest of the arteries
what is the composition of capillaries
- vessel diameter is only slightly larger than diameter of erythrocytes
- only have tunica intima
function of venules
collect blood from capillaries
composition of veins
- formed when venules unite
- most veins have valves to prevent backflow
- muscular pumps also help blood be pushed on veins toward heart
