Human Physiology Block 4 Lesson 1:Renal Physiology: Structure and Basic Processes

What are some functions of the kidneys?

-regulate water and inorganic ion balance

-acid-base balance

-eliminate metabolic products

-gluconeogensis

-secrete hormones

What is the cortex?

outer layer, site of glomerular filtration and convoluted tubules

What is the medulla?

location longer loops of Henle, drainage of collecting ducts into renal pelvis and ureter

What is the nephrons?

hollow tubes with filtered plasma in the lumen and capillary at the epithelial cell base

What makes up the basic structure of a nephron?

-renal corpulse

-proximal tubule

-loop of hence:ascending limb, descending limb

-distal(distant) tubule

-collecting duct

What are nephrons?

structural and functional units of kidney

What does each nephron have?

glomerulus which is a tuft of capillaries and renal tubule

What is a Bowmans capsule?

tubule forms cup shape around glomerulus

What are cortisol nephrons?

-most nephrons are in this category

-short loops of henle

What are juxtamedullary nephrons?

-long loops of henle

-involved in concentration of urine

What is the vascular space?

-glomerular capillaries

-contains plasma, RBCs, WBCs, protiens, electrolytes, etc

What is the urinary space?

-Bowmans space

-contains ultra filtrate of plasma

-filtrate passes from vasculature into tubule system

-1st step in urine formation

What is the kidney circulation?

AA>Glomerulus>EA>Peritubular>vasa recta

What are the two arterioles?

-afferent arteriole

-efferent arteriole

glomerular capillaries

filtration

pertitubular capillaries

reabsorption, secretion

vasa recta capillaires

concentration

What is glomerular capillaries specialized for?

filtration

Filtration

glomerular capillary lumen-bowman space (bulk flow)

Tubular reabsorption

tubular lumen-peritubular capillary plasma

Tubular secretion

peritubular plasma-interstitial space-tubular cell-tubular lumen

Glomerular capillary epithelium

vascular

Basement membrane

shared

Podocytes

bowmans capsule

What are glomerular capillaries role in the glomerular filtration barrier?

-fenestrated, allow large amounts of solute-rich fluid to pass

-filtrate normally low in protein, too large to cross capillaries

What is the basement membrane role in glomerular filtration barrier?

-produced by endothelial cells and podocytes

What are the podocytes role in the glomerular filtration barrier?

-inner layer of the glomerular capsule, highly modified branching epithelial cells

What are foot processes ?

podoctye termination, surround basement membrane of glomerulus

What are filtration slits ?

clefts between foot processes where filtrate enters capsular space

What are the starling forces at the glomerulus?

forces that determine net filtration pressure across capillaries

Hydrostatic pressure

P

Oncotic pressure

pi

PGc

glomerular capillary blood pressure

PBs

fluid pressure in bowmans space

piGc

glomerular capillary oncotic force

piBs

?

What are the two forces that favor fluid filtration?

-PGc

-piBs

What are two forces that oppose fluid filtartion?

-piGc

-PBs

favor filtration

glomerular capillary blood pressure(PGc)

opposing filtration

-fluid pressure in bowmans space (PBs)

-osmotic force due to protein in plasma(piGc)

What is the net glomerular filtration pressure?

PGc-PBs--piGc