Summary of Nephron Function and Structure
| AREA | PROCESS | HISTOLOGY, ETC. |
| afferent arteriole | vasodilates in autoregulation w/ low b.p.
vasocostricts in autoreg. w/ high b.p.
vasoconstricts from sympathetic stim. |
<-- Juxta-glomerular apparatus connection |
| glomerulus | filtration of water and dissolved substances out of the blood | fenestrated capillaries |
| efferent arteriole | vasoconstricts due to angiotensin II | <-- renin from J.G cells |
| Bowman's capsule | filtrate begins in capsular space | visceral layer
podocytes
parietal layer simple squamous |
| proximal convoluted tubule | reabsorbs 65% of water, all glucose and
amino acids, Na+Cl-
secretion of toxins, drugs, K+, H+, NH4+ |
cuboidal cells with microvilli |
| descending limb
of Henle's loop |
reabsorption of water due to counter- current mechanisms | thin segment with specialized simple squamous cells |
| ascending limb
of Henle's loop |
reabsorption of Na+Cl- to produce hypertonic medulla | thick segment cuboidal cells |
| descending limb of vasa recta | picks up salt from hypertonic medulla | |
| ascending limb of vasa recta | releases salt back into medulla | |
| distal convoluted tubule | Na+ reabsorbed under control of aldosterone/ some secretion here |
cuboidal epithelium macula densa cells |
| peritubular capillaries | reabsorption occurs into these capillaries which lead to venules and renal veins | |
| collecting duct | facultative water reabsorption under
control of ADH
active transport of K+, H+, NH4+, HCO3-, Cl- |
cuboidal cells |