Download Urinary System

Urinary System
Urinary System Functions
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Remove salts and nitrogenous waste
Maintain water and electrolyte concentration
Regulate pH and volume of fluids
Help control RBC production by secreting
erythropoieten
Made of
– Kidneys-filtering units
– Ureters-transport urine from kidney to bladder
– Bladder-holds urine
– Urethra-gets it out of the body
Label your diagram.
Kidney Function
Remove metabolic waste from blood,
dilute it with water and electrolytes to
form urine
 Secrete erythropoeiten-control RBC
production
 Activation of vitamin D
 Maintain blood volume and pressure
 Retroperitoneally located-behind parietal
peritoneum; left slightly higher than right
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Kidney Structure
Renal sinus-hollow chamber in the kidney
 Renal pelvis-funnel shaped sac
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◦ Divided into major and minor calyces
 Small renal papillae project into minor calyces
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2 major portions of the kidney
◦ Medulla-houses tubes leading to papillae
◦ Cortex-has functional unit of kidneys called
nephrons
Label the diagram on your sheet.
Renal blood flow
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Renal arteries branch off the abdominal
aorta
◦ These branch into smaller arterioles
 Afferent arteriole-leads to the nephron
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Renal vein leaves the kidney and attaches
to the inferior vena cava
Nephron-1 million nephrons per
kidney
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2 parts
– Renal corpuscle-filtering portion of the kidney
• Glomerulus-ball of capillaries
– Blood is filtered here
– Capillaries have tiny openings called fenestrae to increase
permeability
• Glomerulus capsule (Bowman’s capsule) -surrounds
the glomerulus
– Receives the fluid the glomerulus filters
– Renal tubule-tube that leaves the glomerulus
capsule
Label the diagram.
Nephron blood supply
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Afferent arterioles-lead into the
capillaries of the glomerulus
Efferent arterioles (smaller)-blood flows
into these after filtration in the
glomerulus
Peritubular capillaries-efferent arterioles
branch into these
– Surround the renal tubule
– Reabsorption and secretion here
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Blood enters the venous system
Juxtaglomerular Apparatus
Cells that come in contact with the glomerulus
• 3 parts
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– Juxtaglomerular cells-smooth muscle cells
• Contain renin (discuss later)
– Tubule
– Macula densa-densely packed epithelial cells
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Come in contract with afferent and efferent
arterioles
– Help to determine blood pressure
• Caused by stretch of cells in this area
• http://www.wisc-online.com/objects/AP2204/AP2204.swf