The kidney

Kidney and bladder position

Excretion by the Kidney Urea -nitrogenous waste -made by liver -excess amino acids in blood -toxic Why must nitrogenous waste be excreted?

Kidney transplant

Cross section

X section to nephron

Filtration by the Kidney Supplied with blood from renal artery Inside it splits into many fine capillaries Each capillary supplies blood to hundreds of thousands of tiny filtration units called nephrons Renal artery Renal vein Ureter

Re-absorption by the Kidney Once the main components of filtrate enter the kidney -they are no longer in bloodstream If nothing more happened in the nephron then all the useful stuff would be lost in the urine! Therefore, glucose, water and some salts need to be reabsorbed!

More water reabsorbed Variable amounts of water and salts reabsorbed and filtrate gradually turning into urine Glucose reabsorbed Final urine containing: -excess water -unneeded salts -waste urea

Classwork: Ticket to Leave: Write one paragraph in your notebook on why the liver and kidneys belong to the circulatory system. Extra credit if you can tell me how the small intestines connects to the circulatory system. Ticket to Leave: 6 multiple choice mcas questions on the half sheet on the ELMO projector