Blood Vessels Flashcards
Tunica Interna
innermost layer of arteries containing endothelium
Tunica Media
middle layer of arteries
smooth muscle maintains elasticity and contractility for vasoconstriction and vasodilation
Tunica Externa
Outer layer
primarily elastic and collagen fibers
Vasa Vasorum
supplies tunics with blood
Large sized Arteries
large thick walls near heart
tunica media has more elastic fibers and less smooth muscle
conducts blood from heat to medium sized arteries
Medium sized Arteries
delivers blood to specific organs
Arterioles
arteries that deliver blood to capillaries
regulate blood flow via vasocon/dilate
Capillaries
made of only tunica interna
exchange nutrients and wastes b/t blood and tissue
not in cornea, lense, epidermis, cartilage
Continuous Capillaries
complete endothelial lining
skeletal, smooth, CT, lung
permit diffusion of water, small solutes, lipid soluble
prevents loss of blood cells and plasma
Fenestrated Capillaries
oval shaped pores
rapid exchange of water and other substances in or out
kidney, villi of SI, ciliary process of eyes
Sinusoids
Sinusoidal Capillaries
gaps b/t adjacent endothelial cells that allow passage of blood cells
liver, spleen, bone marrow
monitored by phagocytes
Capillary Bed
Capillary Plexus
networks connecting arteriole to venule
Metarteriole
emerges from precapillary sphincter on arteriole, nourishes cap plexus, empties into venule
Precapillary Sphincter
control blood flow through true capillaries
Venules
receive blood from capillaries and merge into veins
