Excretory SystemExcretory System

PurposePurpose

Remove metabolic waste Remove metabolic waste from the body.from the body.

MetabolismMetabolism

Sum total of chemical reactions that Sum total of chemical reactions that keep and organism alivekeep and organism alive

Metabolic WasteMetabolic Waste by product of by product of metabolismmetabolism

LungsLungs

Carbon dioxide accumulates in blood Carbon dioxide accumulates in blood to circulate to lungs to get oxygento circulate to lungs to get oxygen

LiverLiver

Proteins and other nitrogenous Proteins and other nitrogenous compounds are broken down in the compounds are broken down in the liver (urea)liver (urea)

SkinSkin

Sweat from pores allows wastes to Sweat from pores allows wastes to diffuse from blood and into sweat diffuse from blood and into sweat glandsglands

KidneysKidneys

Filters the blood, removing Filters the blood, removing nitrogenous wastes and nitrogenous wastes and toxinstoxins

UretersUreters

Drains urine produced in Drains urine produced in the kidneys into the the kidneys into the bladder.bladder.

Urinary bladderUrinary bladder

Muscular sac that stores Muscular sac that stores the urine.the urine.

UrethraUrethra

Tube that drains urine Tube that drains urine from the bladder out of the from the bladder out of the body.body.

Kidney StructureKidney Structure

renal cortexrenal cortex- the - the outerouter layer layer renal medullarenal medulla-the -the innerinner layerlayer renal pelvisrenal pelvis ––a funnel-shaped a funnel-shaped

centercenter of the kidney of the kidney Blood enters through Blood enters through renal renal

arteryartery and exits through and exits through renal renal veinvein

Nitrogenous wasteNitrogenous waste The breaking and making of The breaking and making of

proteinsproteins produces produces ammoniaammonia as as a waste in cells.a waste in cells.

AmmoniaAmmonia is HIGHLY toxic and is is HIGHLY toxic and is quickly converted to quickly converted to ureaurea, less , less toxic, in the liver.toxic, in the liver.

UreaUrea is transported in blood is transported in blood into the into the kidneyskidneys..

NephronNephron

Tiny tubular structures in Tiny tubular structures in the kidney that filter out the kidney that filter out the waste in blood creating the waste in blood creating urine.urine.

The nephron is the functional The nephron is the functional unit of the kidney.unit of the kidney.

Nephron StructureNephron Structure Bowman’s Bowman’s

capsulecapsule: : cup-cup-shapedshaped capsule in capsule in which arterioles which arterioles split into fine split into fine capillariescapillaries. .

GlomerulusGlomerulus: : networknetwork of fine of fine capillaries capillaries

Loop of HenleLoop of Henle: : tubetube that is that is connected to the connected to the Bowman’s Bowman’s capsulecapsule

Collecting ductCollecting duct: : tube that leads tube that leads to the to the ureterureter and and out of kidneyout of kidney

Making urineMaking urine1. Blood flows from the 1. Blood flows from the renal renal

arteryartery to the kidneys to the kidneys

2. At the glomerulus, pressure 2. At the glomerulus, pressure forces forces water, urea, glucose, saltswater, urea, glucose, salts and minerals out of the capillaries and minerals out of the capillaries and into the and into the Bowman’s capsuleBowman’s capsule. . Cells and large proteins remain in Cells and large proteins remain in the blood.the blood.

3. The filtrate flows through the 3. The filtrate flows through the Loop of HenleLoop of Henle. As the filtrate . As the filtrate passes, water, glucose, salts passes, water, glucose, salts and minerals are reabsorbed and minerals are reabsorbed by by osmosisosmosis and and active active transporttransport..

4. Filtrate, which is now 4. Filtrate, which is now urineurine, , flows into flows into collecting ductscollecting ducts, , where more water is where more water is reabsorbed. reabsorbed.

5. The collecting ducts 5. The collecting ducts join into the join into the uretersureters and urine follows into and urine follows into the the bladderbladder..

6. The filtered blood 6. The filtered blood returns to the heart returns to the heart through the through the renal veinrenal vein