- The lungs, skin, kidneys, and large intestine are all part of the excretory system. The
urinary system is made up of the kidneys, the ureters, the bladder, and the urethra.
The filtering structures of the kidneys are the nephrons. - Water and waste molecules move out of the blood capillaries and into the nephrons.
Most of the water returns to the blood. Urine collects in the nephron and moves to
the urinary bladder through the ureters. - The filtering action of the kidneys is controlled by the pituitary gland. ADH is the
hormone that controls the uptake of water from the kidneys. Disorders of the urinary
system include kidney stones, kidney disease and urinary tract infections.
Review Questions
- What are the functions of the excretory system?
- List the organs that make up the excretory system.
- What is the difference between the urinary system and the excretory system?
- What is urine made up of?
- Outline how the kidneys filter blood.
- What is the purpose of the urinary bladder?
- The walls of the urinary bladder are stretchy, what do you think is the advantage to
having these stretchy walls? - What connects the kidneys to the urinary bladder?
- What does antidiuretic hormone do?
- What is a urinary tract infection?
- Why is kidney failure such a serious health problem?
Further Reading / Supplemental Links
- http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookEXCRETE
- http://kidney.niddk.nih.gov/kudiseases/pubs/yourkidneys
- http://en.wikipedia.org/wiki
Vocabulary
antidiuretic hormone (ADH) Hormone that controls the absorption of water back into
blood.
excretion The process of removing wastes from the body.
excretory system The organ system that maintains homeostasis by keeping the correct
balance of water and salts in your body; also helps to release wastes from the body.