WJEC Biology 2.6 Role of kidney in homeostasis

Homeostasis

Maintenance of the internal conditions of the body.

Negative feedback

Homeostatic control system where the change brought about removes the initial stimulus.

Positive feedback

Homeostatic control system where the change brought about causes greater change.

Stimulus

An event that is detected by receptors.

Kidney

Organ that controls the water potential of the blood.

Nephron

Microscopic filtering unit within the kidney.

Water regulation

Maintenance of a stable water potential of the blood.

Tubule

Region of the nephron where glucose and water are reabsorbed.

Reabsorption

Process in which useful substances are taken back from the filtrate for use by the body.

Posterior pituitary gland

Tissue in the brain that is responsible for storing and releasing hormones.

Antidiuretic hormone

Hormone that regulates permeability of the final part of the nephron to water.

Excretory product

A substance which is deliberately removed from the blood by the kidneys.

Collecting duct

The last part of the nephron, which reabsorbs water into the blood.

Kidney failure

Medical crisis in which the body loses its ability to filter the blood or maintain water potential effectively.

What are the functions of the kidney?

Regulate water content of the blood Remove waste products from the blood,

What is the name of the solution that contains urea and excess salts?

Urine,

What structures connect the kidneys to the bladder?

Ureters,

Where is the urine stored before it passes out of the body?

Bladder,

What could glucose in the kidney be an indication of?

Diabetes,

Blood or cells in urine could indicate what?

Kidney disease,

High concentration of water in the blood produces what?

Dilute urine,

Low concentration of water in the blood produces what?

Concentrated urine,

As the water level in the blood decreases, there is an increase in the secretion of what?

ADH (antidiuretic hormone),

What does ADH do?

Causes the kidney to reabsorb more water,