Excretory System

What is the main function of the Excretory System?

Removes metabolic wastes and maintains fluid and electrolyte balance.

What is Homeostasis? For kidneys?

Maintaining a stable internal environment; kidneys regulate water, blood pressure, pH, and electrolytes.

What is Excretion?

Eliminating metabolic wastes and toxic materials from the body.

Define Filter.

Separating substances by allowing small molecules through while retaining larger particles.

Define Diffusion

Passive movement from high concentration to low concentration.

What is the function of the kidney?

Filters blood, regulates fluid balance, and produces urine.

What are nephrons? Function?

Microscopic kidney units that filter blood, reabsorb useful substances, and form urine.

What is the function of the glomerulus?

Filters water and small solutes from blood while retaining blood cells and proteins.

How do the kidneys help control blood pressure?

By regulating blood volume and releasing renin.

What is the function of the bladder?

Temporarily stores urine before excretion.

What tube goes between the kidney and the bladder?

Ureter.

What tube leads from the bladder to outside the body?

Urethra.

What is urine?

Liquid waste containing water and dissolved wastes removed by the kidneys.

What are the main components of urine?

About 95% water, urea, mineral salts, and creatinine.

What gives urine its yellow color?

Urochrome (urobilin), a pigment formed during the breakdown of old red blood cells.

What is osmoregulation?

Maintaining water balance and stable concentrations of dissolved substances in body fluids.

What is the function of the sphincter muscles? What happens if it fails?

Controls urine release and helps prevent leaks; failure can cause urinary incontinence.

How does the kidney maintain homeostasis?

Balances pH and electrolytes and adjusts water retention.

How is the skin involved in the excretory system?

Removes excess water, salts, and small amounts of urea through sweat.

How are the lungs involved in the excretory system?

Remove carbon dioxide and water vapor during exhalation.

How is the liver involved in the excretory system?

Converts toxic ammonia into urea for removal by the kidneys.

What are kidney stones?

Hardened mineral and salt crystals that form inside the kidneys.

What causes a UTI? What parts of the excretory system are affected?

Bacteria entering through the urethra; the urethra, bladder, ureters, and kidneys can be affected.

What is nephritis?

Inflammation of the kidneys.

What is diabetes insipidus?

A condition involving insufficient ADH or poor kidney response to ADH, causing excessive dilute urine and extreme thirst.

Identify Structures A, D and E

A: Renal cortex; D: Ureter; E: Renal pyramid.

Identify structures A, B, E and AB

A: Renal vein; B: Glomerulus; E: Bowman’s capsule; AB: Collecting duct.