Term
| What is the peritubular capillary network? |
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Definition
| The affarent arteriole comes into the glomerulus, and then reunites to form the efferent arteriole. The efferent arteriole divides again forming the peritubular capilalry network. They can exchange materials in the tubules for secretion or uptake into the body. Once they leave the nephron, they converge into venules and course back to the systemic circulation |
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Term
| What do the myoepithelial cells in the afferent arterioles do? |
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Definition
| They change the resistance in teh vessel. |
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Term
| Extrinsic vs. Intrinsic Control of Blood Flow |
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Definition
Extrinsic - regulated by sympathetic NS. Catecholamines are vasoconstrictors of afferent and efferent arterioles. Serotonin and ADH are also vasoconstrictors. The Kinins, ANF, and some prostaglandins act as vasodilators.
Intrinsic - Autoregulation. Cells in the wall of afferent arterioles are sensitive to stretch. When the radius is decreased, resistance is increased. Vascular resistance increases as a Fn of arterial pressure |
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Term
| What do granular cells do? |
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Definition
| They make and release renin, adenosine, around the afferent arteriole. Renin results in angiotensin II which would constrict the afferent arteriole by (he isn't sure). Systemically, AII releases aldosterone, which retains Na and increases blood pressure |
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