Adrenal gland The hilus is where nerves and vessels as well as the ureter enter and/or exit

Cortex Renal capsule

BLOOD FLOW THROUGH THE KIDNEYS

RENAL PAPILLA Papilla is where urine enters the major calyx

Arcuate a. Interlobular a. Arcuate v. Afferent arteriole Glomerulus Peritubular capillaries Proximal convoluted tubule Descending tubule Loop of Henle Ascending tubule Collecting duct

Cells of PCT are cuboidal with microvilli. Cells of DCT have little or no microvilli. The purpose of microvilli is is to increase surface area for diffusion of a large quantity of water. Distally, there is very little excess water left.

VOLUMES ALL VOLUMES ARE PER MINUTE 1200cc Blood filtered 125 cc of filtrated enters PCT 124 cc reabsorbed in PCT 1cc urine formed Therefore, about 1% of filtrate becomes urine

REABSORPTION-SECRETION PCT – 100cc water reabsorbed, glucose, amino acids, Na+, Vitamin C Descending loop – water reabsorbed Ascending loop – Na+, Cl- reabsorbed, H+, K+ secreted (moves from capillary to tubule) DCT – water, Ca++, Na+, PO4 (phosphate) (controls blood pressure)

CONTENT OF URINE Urea, uric acid, creatinine, water, small amounts of sodium, chloride and potassium, amino acids, hormones, minerals and much more. NOT FOUND (in healthy individuals) RBCs or WBCs, protein, glucose

DISEASES Infection of the renal pelvis (calyces) is called pyelitis. Probably caused by bacteria from the anus or blood-borne. Prosthatic hyperplasia – causes urinary retention mainly in the elderly Kidney stones – renal calculi caused by inc. Ca++, bacterial infection or dehydration

BOWMAN’S CAPSULE Look at the left side of the slide and notice the visceral and parietal layer (in the form of podocytes) of Bowman’s Capsule. Also look at the capillaries within the capsule. The other white areas are most likely proximal convoluted tubules.

Interlobar a. Arcuate a. Interlobular a. Afferent a.

AFFERENT AND EFFERENT ARTERIOLES The upper portion of the slide where the arcuate arteries are and you may notice interlobar arteries coming up (on the right), then efferents.

Bowman’s capsule Interlobular a. Afferent arteriole Efferent arteriole

GLOMERULI This slide is stained with India ink. Notice the glomeruli and collecting ducts

Parietal layer of Bowman’s cap. Made of simple squamous epithelium Visceral layer (podocytes) filtrate Capillary bed

BOWMAN’S CAPSULE A very close shot of the visceral and parietal layers. You can see the capillaries and the space where the filtrate is squeezed out, and then moving to the proximal convoluted tubules.

Parietal layer of Bowman’s cap. Made of simple squamous epithelium Visceral layer (podocytes) filtrate Capillary bed

Afferent arteriole Efferent arteriole Proximal convoluted tubule

BOWMAN’S CAPSULE

Afferent arteriole Efferent arteriole Proximal convoluted tubule

AFFERENT AND EFFERENT ARTERIOLES On the left is either an afferent or efferent arteriole. It is very rare to find a good slide like this

PCT Notice the “brush border” on the PCT Brush border is a name given prior to advanced microscopy. They are now known to be microvilli 100ml of water needs to be reabsorbed here per minute! That’s why the surface area needs to be increased

PCT Closer view

LOOP OF HENLE Beautiful and rare longitudinal view of the loop of Henle

COLLECTING DUCT

CROSS SECTION OF COLLECTING DUCT