URINARY/EXCRETORY SYSTEM Chapter 20 URINARY/EXCRETORY SYSTEM

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. URINARY SYSTEM © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. URINARY SYSTEM The urinary system consists of: Two kidneys Two ureters Bladder Urethra © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

FUNCTIONS OF THE URINARY SYSTEM Excretion Aid in maintaining acid-base balance Secretion of waste in urine Elimination of urine from bladder © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. KIDNEYS © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. KIDNEYS The kidneys have the potential to work harder than they actually do in case one kidney should fail, the other would be able to take over full capacity The kidney is divided into 2 layers Cortex - outer, granular layer Medulla - inner, striated layer © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. NEPHRON The nephron is the basic structural and functional unit of the kidney Each kidney has more than one million nephrons © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

URINE FORMATION IN THE NEPHRON 3 processes of urine formation Filtration by the glomerulus Reabsorption within the renal tubules Secretion by the tubular cells Urinary output is between 1,000 and 2,000 ml/24 hours © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. URETERS There are two ureters (one per kidney) that carry urine from the kidneys to the bladder © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. URINARY BLADDER The urinary bladder is a hollow, muscular organ made of elastic fibers and involuntary muscle The urinary bladder stores urine until about 1 pint (500ml) is accumulated © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

CONTROL OF URINARY SECRETION Chemical control Nervous control © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

DISORDERS OF THE URINARY SYSTEM Acute kidney failure Chronic renal failure Glomerulonephritis Acute glomerulonephritis Chronic glomerulonephritis Hydronephrosis Pyelonephritis Kidney stones Cystitis Incontinence Neurogenic bladder © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

DISORDERS OF THE URINARY SYSTEM Dialysis is the treatment for kidney failure in which blood is passed through a device in order to remove waste, salt, and excess water from the blood Hemodialysis dialysis Peritoneal dialysis © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

DISORDERS OF THE URINARY SYSTEM Kidney transplants are performed in cases of chronic and debilitating kidney disease and renal failure of both kidneys © 2004 Delmar Learning, a Division of Thomson Learning, Inc.