Week 7 Flashcards
what is the size and shape of a red blood cell?
small bioconcave discs that are plump at periphery and thin in the center with a diameter of 7-8 micrometers.
do the rbc have a nucleus?
no nucleus
what allows for the ability of rbc to reproduce?
reproduce with the help of hematopoiesis.
what is the main function of rbc in the body?
transport nutrients and exchange gases.
how does the shape and size of rbc facilitate function?
the bioconcave shape provides a greater surface area where gas exchange can occur efficiently.
what are the different layers of blood vessels?
tunica interna: composed of simple squamous epithelium aka endothelium and a thin layer of connective tissue under it.
tunica media: middle layer, thicker in arteries than veins. composed of smooth muscle, elastic fibers, collagen fibers.
tunica externa: outer layer and is mainly composed of connective tissue/collagen fibers
what is an artery?
blood vessel that takes blood away from the heart : thick walls that withstand high pressure.
what are arterioles?
small branch of an artery that leads to capillaries. arterioles regulate blood flow into capillaries by constricting or dilating.
what are capillaries?
tiny thin walled vessels where exchange of oxygen, nutrients, and waste occurs between blood and tissues.
what are veins?
a blood vessel that carries blood back to the heart.
what are venules?
a small vessel that collects blood from capillaries and channels it into larger veins
Distinguish between elastic arteries and muscular arteries…
elastic arteries contain more elastic tissue in the tunica media and muscular arteries contain more smooth muscle in the tunica media. example of elastic arteries: aorta, pulmonary arteries. example of muscular arteries: femoral, radial, ulnar, popliteal, etc.
elastic are larger than muscular and are found closer to the heart.
Explain the relationship between arterioles, vasoconstriction, vasodilation and resistance…
vasoconstriction: narrowing of blood vessels due to contraction of smooth muscle in the vessel walls.
- increased resistance and raises blood pressure
vasodilation: widening of blood vessels due to relaxation of smooth muscle in the vessel walls.
- decreases resistance and lowers blood pressure.
arterioles regulate blood flow and pressure by changing their diameter which is directly related to resistance which is related to vaso constriction/dilation.
