The Excretory System

What is the main function of the excretory system?

• to collect and remove wastes from the body
• to strengthen skeletal muscles
• to protect the nervous system
• to bring oxygen to body cells

Which organ of the excretory system stores urine until the body is ready to eliminate it?

• ureters
• urethra
• urinary bladder
• urea

Tiny filtering structures where urine is produced in the kidneys are called

• ureters.
• alveoli.
• nephrons.
• bronchi.

Under normal conditions, which of the following substances is found in urine?

• blood cells
• protein
• glucose
• urea

In which excretory organ is urea produced?

• skin
• liver
• kidneys
• lungs

Which excretory organ eliminates water and some chemical wastes in perspiration?

• lungs
• skin
• liver
• kidneys

What term do scientists use to describe the chemical process in which oxygen and glucose react to release energy inside body cells?

• respiration
• exhaling
• breathing
• inhaling

What function do the kidneys perform?

• eliminate carbon dioxide
• supply oxygen to body cells
• remove urea and excess water
• play a role in gas exchange

The process of removal of the body’s wastes is called

• gas exchange.
• respiration.
• excretion.
• filtration.

Organs of excretion that maintain homeostasis include the kidneys, lungs, skin, and

• bronchus.
• diaphragm.
• bladder.
• liver.