Human Excretion and Kidney Physiology

If drugs are given which inhibit sodium reabsorption, then there is more sodium in the tubules and this means that more water stays in the tubules with it because of the osmotic effect of the sodium. Such drugs are known as diuretics because they increase the amount of water excretion. Diuretics such as furosemide (frusemide) inhibit sodium reabsorption in the loop of henle, drugs such as the thiazides oppose sodium reabsorption in the distal tubule and drugs such as amiloride oppose sodium reabsorption in the collecting ducts.

There are buffers in the urine, including sodium phosphate. In addition, hydrogen ions can be excreted in the form of ammonium ions (NH4⁺) in the urine. The buffers are necessary because urine cannot be made very acidic because below a certain pH, the hydrogen ion gradient across the tubule wall cannot be maintained.

‘Diaysis’ is used in case of patients suffering from disease related to kidneys

Dialysis works by using a semipermeable membrane to separate waste products from the blood. The movement of small molecules through this membrane based on concentration gradients is known as osmosis.

Dialysis is a medical procedure used to perform the function of the kidneys for patients whose kidneys are failing, specifically to remove waste products and excess fluid from the blood.

This is because some glucose is used up in respiration of kidney cells.

The main excretory organ in man, are the kidneys. They excrete urine. The right kidney is lower than the left because of the presence of liver, in the abdominal cavity.

Gout is a medical condition, usually characterized by recurrent attacks, of acute inflammatory arthritis—a red, tender, hot, swollen joint. The metatarsal-phalangeal joint at the base of the big toe, is most commonly affected.

The glomerulus lining is such that it only allows small molecules to filter through, like glucose, plasma, ions like sodium and potassium, urea, etc. The larger molecules, like blood cells and protein, cannot pass through the glomerulus. Thus protein is not present in urine.

The human spleen is an organ, that creates lymphocytes for the destruction and recycling, of old red-blood cells. The spleen is also a blood reservoir. It supplies the body with blood in emergencies, such as, a bad cut. The spleen does not help in excretion.

Anthrax is an acute disease, caused by the bacterium, Bacillus anthracis. Most forms of the disease are lethal, and it affects both humans and other animals. There are effective vaccines against anthrax, and some forms of the disease respond well, to antibiotic treatment. A diuretic may not be effective in anthrax.

The process by which, the water content and the ion concentration is regulated and kept constant, in the cells is known as osmoregulation. Kidneys perform both excretion and osmoregulation.

The final passageway for the flow of urine, is the urethra, a thin-walled tube that conveys urine, from the floor of the urinary bladder, to the outside. The opening to the outside is the external urethral orifice. The mucosal lining of the urethra is transitional epithelium. The wall also contains smooth muscle fibers, and is supported by connective tissue.

The urinary bladder is a temporary storage reservoir for urine. It is located in the pelvic cavity, posterior to the symphysis pubis, and below the parietal peritoneum. The size and shape of the urinary bladder, varies with the amount of urine it contains, and with pressure it receives from surrounding organs.

The gallbladder is a small pear-shaped organ, that stores and concentrates bile. The gallbladder is connected to the liver by the hepatic duct. It is approximately 3 to 4 inches (7.6 to 10.2 cm) long and about 1 inch (2.5 cm) wide. The function of the gallbladder, is to store bile and concentrate.