Chapter 15: Cardiovascular System Flashcards
blood vessels
organs of the cardiovascular system; forms closed circuits and transport blood from heart, to body cells, and back to heart
types of blood vessels (5)
- arteries
- arterioles
- capillaries
- venules
- veins
arteries
carry blood away from ventricles of the heart
arterioles
receive blood from arteries & carry it to capillaries
capillaries
1 cell layer thick; endothelial, sites of exchange between body cells & blood
venules
receive blood from the capillaries & conduct it to veins
veins
receive blood from venules & carry it back to atria of heart
3 layers of arteries
- interna
- media
- externa
interna
innermost layer of arteries
media
smooth muscle & elastic tissue; thicker in arteries than in veins
externa
outer layer, connective tissue of arteries
what do arteries do?
transport blood under high pressure; give rise to arterioles
what can both arteries & arterioles undergo?
vasocontstriction & vasodilation
what do capillaries do?
- connect smallest arterioles & smallest venules
- blood flow regulated by precapillary sphincters
precapillary sphincters
smooth muscles surrounding capillary when it branches off arteriole or met arteriole