Cardiac System Flashcards
what is the circulatory system responsible for?
the internal transport of substances to and from the cells
what are the 3 parts of the circulatory system?
- blood
- blood vessels
- heart
what is blood composed of?
water, solutes, and other elements in a fluid connective tissue
blood vessels
tubules of diff. sizes that transport blood
heart
muscular pump that provides the pressure necessary to keep blood flowing
closed circulatory system
the heart and blood vessels are continually connected (most animals have this)
how is the flow of blood in capillary beds?
slow
lymph vascular system
cleans up excess fluids and proteins and returns them to the circulatory system
what 3 layers do the walls of all blood vessels consist of?
- what is the exception to this?
tunica intima (innermost layer), tunica media (made up of smooth muscle cells and elastic fibers), and tunica adventitia (outermost layer)
- capillaries
what is the structure of elastic arteries?
- function?
includes aorta and major branches, tunica media qhas more elastin than any other vessels, largest vessels in the arterial system
- stretch when blood is forced out of the heart, recoil under low pressure
what is the structure of muscular arteries?
- function?
includes the arteries that branch off the elastic arteries, tunica media has a higher proportion of smooth muscle cells and fewer elastic fibers as compared to elastic arteries
- regulate blood flow by vasoconstriction/ vasodilation
what is the structure of arterioles?
- function?
tiny vessels that lead to the capillary beds, tunica media is thin but composed almost entirely of smooth muscle cells
- primary vessels involved in vasoconstriction/ vasodilation, control blood flow to capillaries
what is the structure of arterioles?
- function?
tiny vessels that lead to the capillary beds, tunica media is thin but composed almost entirely of smooth muscle cells
- primary vessels involved in vasoconstriction/ vasodilation, control blood flow to capillaries
what is the structure of venules?
- function?
tiny vessels that exit the capillary beds, thin porous walls, few muscle cells and elastic fibers
- empty blood into larger veins
what is the structure of veins?
- function?
thin tunica media and tunica intima, wide lumen, valves prevent backflow of blood
- carry blood back to the heart
how much blood does an adult human have?
5 quarts
what is blood made up of?
red and white blood cells, platelets, plasma
what percentage of blood does plasma take up?
- what is plasma?
over 50%
- made up of mostly water and serves as a solvent. contains plasma proteins, ions, glucose amino acids, hormones, dissolved gases