FOCUS ON THE KIDNEYS

Functions:• Filter wastes: Every day, kidneys process about 200

quarts of blood to filter out about 2 quarts of waste products and extra water

• Regulate composition of electrolytes: The kidneys measure out chemicals like sodium, phosphorus, and potassium and release them back to the blood to return to the body. In this way, the kidneys regulate the body’s level of these substances.

• Maintain pH: filter H+ ions• Secrete hormones and enzymes:

-erythropoietin: stimulates the bone marrow to make red blood cells (hormone)-renin: regulates blood pressure (enzyme)-calcitriol: helps maintain proper calcium levels (hormone)

Kidneys and urine formation

1. Blood enters the kidney through the renal artery

Identify:

-kidney

-abdominal aorta

-renal artery

2. Blood enters the functional unit of the kidney called the nephron.

One kidney contains about one million nephrons.

Stop and take the kidney quiz

• 3 Filtration of the blood takes place in the renal corpuscle which is made of a glomerulus and a glomerular capsule.

 

3. The filtrate goes into the glomerular capsule and includes water, amino acids, vitamins, glucose, and nitrogenous wastes. Cells and large proteins are left in the arteriole.

4. Tubular reabsorption

The blood reabsorbs needed substances from the proximal convoluted tubule-water-amino acids-glucose-ions: Na, Cl, Ca, K-bicarbonate-some urea

The glomeruli and tubules together make up long and extremely fine tubes which, if connected, would run for 50 miles. 

5. Tubular Secretion

Additional items are added to the forming urine.-H+-ammonia-urea-potassium

Link- Use this to review

6. Filtered blood exits the kidneys by way of the renal vein

Identify the renal vein

and inferior vena cava

7. Wastes removed by the kidney pass through collecting ducts then the ureter to the bladder.

8. When the bladder is full, the urine passes out of the body through the urethra.

Summary

What can go wrong?

High Blood PressureWhat part of the nephron would be damaged by high blood pressure?

What does the glomerulus do?

Filters blood.

Diseases of the glomerulus

What is in the urine that should not be?

Polycystic kidney disease (inherited)

. Trauma- such as a direct and forceful blow

to the kidneys, can lead to kidney disease

Ingestions of poisons

What happens when kidneys fail completely?

1. The body fills with extra water and waste products (uremia). Hands or feet may swell. A person will feel tired and weak because the body needs clean blood to function properly.

2. Untreated uremia may lead to seizures or coma and will ultimately result in death.

3. A person whose kidneys stop working completely will need to undergo dialysis or kidney transplantation.

Treatment

• Dialysis

• Transplant

Home dialysis

Preview to transplant