Urinary System Case

Urinary system

• Functions: extrete wastes from body

• Eliminate discharge of waste Into environment
• Homeostatic regulation of volume and solute concentration of blood plasma

• Kidneys perform major functions of the urinary sstem by producing urine

• Urine- fluid containing water, ions, and compounds flowing along the urinary tract

• Urinary bladder: muscular sac holding urine
• Ureters are paired, connecting kidneys to bladder
• Urine leaves body through the urethra

•  Process called urination

• Other homeostatic functions:

• Regulates blood volume and pressure
• Plasma concentration of Na,Cl, K and other ions
• Stabilize blood pH by loosing H and HCO3-
• Conserve nutrients
• Assisting liver in detoxifying poisons

• Kidneys

• Located between T12 ad L3

• Caped at adrenal glands

• Contain nephrons: functional units of kidneys

• Perform filtration reabsorption and secretion

• 3 layers of connective tissue that protect and stabilize the kidneys
• Renal capsule: collagen fibers
• Adipose fat capsule –adipose tissue
• Renal fasciae – dense fibrous outer layer

• Posteriorly – renal fascai fuses with deep fasciae of muscles
• Anteriorly – renal fasciae forms thick layer fusing with peritoneum
• Hilum: point of indentation

• Layers of the kidney

• Renal cortex renal medulla-

• Consists of 6-8 renal pyramids
• Tip of pyramid – renal papilla
• Renal columns – spereate each renal pyramid

• Extend to medulla

• Minor calyx – 3 or 4 make up the major calyx
• Major calyx – 2 or 3 make up the renal pelvis
• Renal pelvis fills renal sinus and drains it to the ureters
• Urine production begins at the nephrons in cortex of each renal lobe

• Blood supply and innervation of kidney

• Kidneys receive 20% of cardiac output

• Receives blood from renal artery that comes from abdominal aorta

• As it enters the renal sinus, it gives off segmental arteries
• Divides into interlobar arteries and radiates outward through renal columns
• Supplies the blood to arcuate arteries

• Arcuate arteries stay between cortex and medulla

• Gives rise to interlobular arteries
• Gives off afferent atriole

• Nephron

• Consists of renal corpuscle and renal tubule

• Corpuscle  - contains Bowman’s capsule and glomerulus
• Renal tubule – 2 inch tube

• Blood arrives at corpuscle from afferent arteriole
• Goes to glomerulus  ( 50 intertwining capillaries)

• Goes to glomerulus capsule

• Leaves glomerulus through efferent atriole
• Goes to peritubular cap

• Surround renal tubular
• Drain venules

• Filtration

• Takes place in corpuscle

• Blood pressure forces water and solutes out and into capsular space
• Creates filtrate – protein free solution

• Filtrate enters tubule to: