Excretion

I. Wastes A.Toxic wastes are excreted B.Nontoxic wastes are excreted or recycled to be used again C.Respiration = CO 2 + Water D.Protein Metabolism = Urea (made from breaking down amino acids)

II. Excretory Organs A.Lungs 1.Excretion of CO 2 and water (from respiration) B.Liver 1.Gets rid of excess a.a. 2.Changes a.a. into urea 3.Also breaks down old/damaged RBCs

II. Excretory Organs C.Skin 1.Sweat glands excrete wastes (water, salts, small amount of urea) 2.Wastes diffuse from capillaries into sweat glands and through ducts to pores on skin 3.Mixture of wastes and water = sweat (perspiration) 4.Perspiration evaporates to dec body temp (homeostasis)

II. Excretory Organs

III. Urinary System A.Kidneys 1.2 functions a.remove urea from blood b.control [substances] in body fluids 2.Blood carried to each kidney by artery and branches into balls of capillaries, glomeruli. 3.Each glomerulus is part of nephron, functional unit of kidney. About 1 million nephrons in kidney

III. Urinary System

Bowman’s Capsule Materials (water, salts glucose, amino acids, hormones) diffuse into Bowman’s Capsule 2.Water, salts, glucose and amino acids diffuse back into blood 3.Hormones, more salt and water actively transported back into blood

III. Urinary System B.Ureters and Urinary Bladder 1.Urine flows from each kidney into large tube (ureter) 2.Then urine goes to urinary bladder (stored) C.Urethra 1.Urine periodically expelled from bladder into tube, urethra, and is expelled from body

III. Urinary System

IV. Disorders A.Gout 1.Buildup of uric acid in joints 2.Severe pain and stiffness of joints

IV. Disorders B.Kidney Stone 1.Hardened cholesterol deposits. Pass from Kidney through system. Ultimately passed through urethra in urine.