Excretory System Flashcards
Metabolic Wastes
a product of a cell’s metabolism (chemical reactions) that is either harmful to the cell or the cell cannot use
Excretion
removal of wastes from an organism
Purpose of excretion
to get rid of metabolic wastes to maintain homeostasis
Parts of the urinary system
kidney, ureter, urinary bladder, urethra
Function of Kidney
to filter wastes from the blood and then produce urine, regulates water and salt balance
Function of Ureter
to transport urine from the kidneys to the urinary bladder
Function of Urinary Bladder
to store urine
Function of Urethra
to release urine
What are the organs of excretion?
skin, lungs, liver, and the entire urinary system
How does the skin contribute to excretion?
excretes sweat which contains water, salts, and small amounts of urea
How do the lungs contribute to excretion?
Removal of carbon dioxide from the body (and small amounts of water vapor) through exhaling
How does the liver contribute to excretion?
converts toxic substances into that aren’t as harmful (and makes bile)
(ex. ammonia to urea)
nephron
one of millions of tubes and its associated blood vessels in the kidneys that extract materials from the blood and refine it into urine
glomerulus
ball of capillaries sitting in the cup-shaped structure of the nephron called Bowman’s capsule
Bowman’s capsule
cup-shaped structure in the upper end of a nephron that encases the glomerulus
How is the circulatory system related to the excretory system?
the kidney filters blood that goes through the capillaries and gets rid of the waste and reabsorbs the necessary substances
Three steps of formation of urine
filtration, reabsorption, excretion
Filtration
blood pressure forces water, small solutes, glucose, amino acids and urea into Bowman’s capsule. This creates the filtrate.
Reabsorption
water, nutrients and some salts are returned to blood from the filtrate
Complete Reabsorption
return glucose and amino acids to blood
Selective Reabsorption
balance water and salt (homeostasis)
Excretion (part of urine formation)
remaining is urine and is transported to the bladder and eventually leaves the body through the urethra
What parts of the formation of urine is the kidney apart of?
filtration and reabsorption
