biology chapter 8 excretion Flashcards
(32 cards)
What is urea?
urea is converted from parts of the excess amino acid molecules that were deaminated in the liver.
What happens when there is an unusually high concentration of urea in the blood?
abdominal pain, nausea, vomiting
what are considered metabolic waste products?
urea, carbon dioxide, mineral salts, water
what are metabolic activities?
they are chemical activities that occur within our body cells to maintain life.
what are metabolic waste products (excretory products)?
they are substances that are produced during metabolic activities that are harmful or toxic to the body.
What is deamination?
it is the removal of nitrogen-containing part of amino acids to form urea.
what is excretion?
it is the removal of metabolic waste products, toxic substances and substances in excess of the body’s requirements.
What does the human urinary system consist of?
a pair of kidneys, a pair of ureters, a urinary bladder and the urethra.
what is the function of the kidneys?
they excrete urea and excess salt and water as urine.
what is the ureter and its function?
it is a narrow tube that connects the kidney to the urinary bladder. its function is to allow urine from each kidney to pass through to go to the bladder.
what is the urinary bladder and its function?
it is an elastic muscular bag located at the front of the rectum, its function is to store urine.
what is the urethra?
it is the duct in which urine passes through from the bladder to outside the body.
how is carbon dioxide found in the body?
it is a product of aerobic respiration.
what happens if there is unusually high concentrations of carbon dioxide in the blood?
hypercarbia, where you suffer from headaches, confusion, rapid breathing and premature heartbeats.
what happens to the body if there is an excess amount of mineral salts in the blood?
it increases the concentration of blood plasma, which results in a lower water potential, leading to water leaving tissue cells and into blood. this leaves the cells dehydrated.
what happens when there is excess water in blood?
it increases the water potential in blood plasma, resulting in more water entering tissue cells which leads to the cells swelling and bursting.
why is excretion necessary?
it prevents the accumulation of unwanted substances so that they do not reach a level that is harmful to the body.
what blood vessels are associated with the urinary system?
aorta, vena cava, renal artery, renal vein
what is the function of the renal artery and vein?
the renal artery brings blood rich in excretory products to the kidneys while the renal vein brings blood without excretory products to the vena cava.
what are nephrons?
they are the basic functional units of the kidneys. they are tiny kidney tubules where urine is formed.
what is ultrafiltration?
it is the first stage of urine formation and is the process by which small molecules are filtered out of the blood by the glomerulus into the Bowman’s capsule.
what is selective reabsorption?
it is the second stage of urine formation and is the process by which useful substances in the filtrate are reabsorbed back into the blood capillaries as the filtrate passes along the nephron.
what are the four main part of the nephron?
the Bowman’s capsule, the proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule. several nephrons also open up into the collecting duct.
describe the Bowman’s capsule.
it is the cup shaped structure in the outer region of the kidney, containing a network of blood capillaries called the glomerulus.
