Chapter 20 URINARYEXCRETORY SYSTEM 2004 Delmar Learning a

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.

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.

KIDNEYS © 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.

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.

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.

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 (500 ml) 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 – 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.