what are the three layers of blood vessels? List from superficial to deep
- tunica externa/tunica adventitia
- tunica media
- tunica interna/ tunica intima
what is the tunica externa?
- outermost blood vessel layer
- adjacent to surrounding tissue
what is the tunica media?
- middle layer of blood vessels
- contains smooth muscle and elastic fibers
what is the tunica interna?
- innermost blood vessel layer
- epithelial
- adjacent to lumen of blood vessel
- direct contact w blood
what is the lumen?
The space within an artery, vein, intestine, renal tubule, or other tubular structure
what is the endothelium?
innermost layer of tunica intima that is continuous with the endocardial lining of the heart
what is the function of endothelial cells?
- assist with capillary permeability
- smooth luminal surface facilitiates efficient blood flow by reducing surface friction
how does the cardiovascular system contribute to homeostasis?
- transportation and distribution of blood throughout body to deliver materials and carry away wastes
how do blood vessels contribute to homeostasis?
- provides structures for the flow of blood to and from heart and the exchange of nutrients and wastes in tissues
- adjusts velocity and volume of blood flow
what are the five main types of blood vessels?
- artieries
- arterioles
- capillaries
- venules
- veins
what are arteries?
blood vessels that carry blood away from heart to other organs
what are arterioles?
small, almost microscopic, arteries that deliver blood to a capillary
what are blood capillaries?
A microscopic blood vessel located between an arteriole and venule through which materials are exchanged between blood and interstitial fluid
what allows for exchange in capillaries?
the thin walls of capillaries allow the exchange of substances between the blood and body tissues
what are venules?
small veins that collects blood from capillaries and delivers it to a vein
what are veins?
blood vessels that carry blood from tissues back towards the heart
what is angiogenesis?
growth of new blood vessels
when is angiogenesis beneficial?
- embryonic and fetal development
- postnatal life: wound healing
when is angiogenesis harmful?
- malignant tumors can secrete tumor angiogenesis factors that stimulate blood vessel growth to provide nourishment for the tumour cells
