THE URINARY SYSTEM Chapter 20 – Page 774. Function Maintain homeostasis through composition, pH, and volume Excretes foreign substances.

THE URINARY SYSTEM

Chapter 20 – Page 774

Function

Maintain homeostasis through composition, pH, and volume

Excretes foreign substances.

Structures of the System

Kidney’s – create urine by filtering the blood

Structures of the System

Ureters – carry urine from kidney to urinary bladder

Structures of the System

Urinary bladder – stores urine

Structures of the System

Urethra – tube emptying the urinary bladder

Catheter

Kidney Stones

Prevention

Drink enough water to form 2 quarts of urine in every 24-hour period.

Incontinence

The loss of bladder control

Temporary urinary incontinence Alcohol Caffeine Over-hydration Dehydration Medication

Permanent Incontinence

After childbirth Changes with

aging Hysterectomy Enlarged prostate Prostate cancer Neurological

disorders obstructions

The Nephron

Structures of the Nephron

• Glomerulus: mechanically filters blood

• Bowman's Capsule: mechanically filters blood

• Proximal Convoluted Tubule: Reabsorbs 75% of the water, salts, glucose, and amino acids

• Loop of Henle: Countercurrent exchange, which maintains the concentration gradient

• Distal Convoluted Tubule: Tubular secretion of H ions, potassium, and certain drugs.

Kidney Functions (All occur in NEPHRONS 1,250,000 / kidney)

Filtration - High pressure at the glomerulus filters:___ out of the blood into the filtrate

a. Waterb. Glucosec. Saltsd. Amino Acidse. Urea

Kidney Functions (All occur in NEPHRONS 1,250,000 / kidney)

Reabsorption (From filtrate) – Loop of Henle

99% water (178 liters/day) 100% glucose (180 g/day) 91% salts (1 300 g/day) 100% amino acids 50% urea

Kidney Functions (All occur in NEPHRONS 1,250,000 / kidney)

Secretion (From blood stream to the distal tubule)

- Uric acid - Creatine - H+

- Ammonia

Kidney Functions (All occur in NEPHRONS 1,250,000 / kidney)

Excretion (Collecting ducts carry urine toward ureters) a.      Water b.     Salts c.      Uric acid d.      Urea e.      Ammonia f.      Creatine

Urine Composition