urinary system

• Renal fascia • Adipose capsule • renal capsule

outer connective tissue layer (anchors kidney)

middle layer of fat (protects + cushions kidney)

innermost layer (thin, tough, protects kidney from infection)

• cortex • medulla • renal pailla

• contains nephrons (filtration units) • looks granular because of the nephrons • site of ultrafiltration (blood pushes thru glomerulus under high pressure) • most water reabsorption happens here

• contains renal pyramids • pyramids contain tubules and collecting ducts • filtrate moves from cortex - medulla - renal papilla

• tip of each pyramid • filtrate (now urine) drips into minor calyces

• minor calyx collects urine from papilla • minor calyces join major calyx • major calyces join renal pelvis • renal pelvis narrows to ureter • ureter carries urine into the bladder

• functional unit of the kidney • has 2 major parts 1. renal corpuscle 2. renal tubule

• filters blood • contains 1. Bowmans capsule 2. Glomerulus

• cup shaped structure • surrounds the glomerulus • collects the filtrate

• ball of capillaries inside Bowmans capsule • has fenestrated (leaky) capillaries • high pressure - pushes fluid out 1. afferent arteriole - wide (brings blood in) 2. efferent arteriole - narrow (takes blood out)

• modifies filtrate/urine • contains 1. proximal convoluted tubule 2. loop of henle 3. distal convoluted tubule 4. collecting duct

• starts at Bowmans capsule • main site of reabsorption • reabsorbs water, glucose, amino acids, ions

• descends into medulla • creates a concentration gradient • reabsorbs water and ions making urine more concentrated • concentrates urine by removing water and salt in different parts.

• fine tunes ion levels • controlled by aldosterone

• final place urine is concentrated • responds to ADH • more ADH = more reabsorbed water = concentrated urine

• filters blood • removes waste • regulates water + electrolytes • makes hormones (EPO + Calcitriol)

• supports capillaries • help regulate blood flow and filtration

• parietal layer • visceral layer

• outer layer • structure

• made of podocytes • podocytes have pedicels, forming filtration slits • these slits + basement membrane = filtration membrane

• first section of Bowmans capsule • lined with cuboidal cells with dense microvilli (huge surface area) • main site of reabsorption (water, glucose, AA) • secretes H+, creatinine