Kidney Functions
•Filters blood plasma, eliminates waste, returns useful chemicals to blood
•Regulates blood volume and pressure
•Regulates osmolarity of body fluids
•Secretes renin, activates angiotensin, aldosterone
–controls BP, electrolyte balance
•Secretes erythropoietin, controls RBC count
•Regulates PCO2 and acid base balance
•Detoxifies free radicals and drugs
•Gluconeogenesis
Nitrogenous Wastes
•Urea
–proteins®amino acids ®NH2 removed ®forms ammonia, liver converts to urea
•Uric acid
–nucleic acid catabolism
•Creatinine
–creatinine phosphate catabolism
•Renal failure
–azotemia: nitrogenous wastes in blood
–uremia: toxic effects as wastes accumulate
Excretion
•Separation of wastes from body fluids and eliminating them
–respiratory system: CO2
–integumentary system: water, salts, lactic acid, urea
–digestive system: water, salts, CO2, lipids, bile pigments, cholesterol
–urinary system: many metabolic wastes, toxins, drugs, hormones, salts, H+ and water
Anatomy of Kidney
•Position, weight and size
–retroperitoneal about 160 g each
–about size of a bar of soap (12x6x3 cm)
•Shape
–lateral surface – convex; medial – concave
•CT coverings
–renal fascia: binds to abdominal wall
–adipose capsule: cushions kidney
–renal capsule: encloses kidney like cellophane wrap
•Renal cortex: outer 1 cm
•Renal medulla: renal columns, pyramids – papilla
•Lobe of kidney: pyramid and it’s overlying cortex
Lobe of Kidney
Kidney: Frontal Section
•Minor calyx: cup over papilla collects urine
Path of Blood Through Kidney
•Renal artery
® interlobar arteries (up renal columns, between lobes)
® arcuate arteries (over pyramids)
® interlobular arteries (up into cortex)
® afferent arterioles
® glomerulus (cluster of capillaries)
® efferent arterioles (near medulla ® vasa recta)
® peritubular capillaries
® interlobular veins ® arcuate veins ® interlobar veins
•Renal vein
Blood Supply Diagram
Renal Corpuscle
Note.
Indepth function of kidney will be discussed in next post. Stay tuned.