Chapter 13: Excretion and homeostasis Flashcards
(21 cards)
excretion
the removal of waste products of metabolism and substances in excess of requirements
urea
a waste product produced in the liver from the breakdown of amino acid
urine
a solution of urea and other waste materials in the water
ureter
one of a pair of tubes that carries urine from the kidneys to the bladder
urethra
the tube that carries urine from the bladder to the outside
deamination
the removal of the nitrogen containing part of amino acids to form of urea
cortex
the tissue making up the outer layer in a kidney
medulla
the tissue making up the inner layers in a kidney
nephron
one of the thousands of microscopic tubes inside a kidney where urine is made
glomeruli
a little network of blood capillaries, where the blood is filtered in a kidney
reabsorbtion
in a kidney nephron, taking back required substances into the blood
homeostasis
the maintenance of a constant internal environment
insulin
a hormone secreted by the pancreas, which decreases blood glucose concentration
glucagon
a hormone secreted by the pancreas, which increases blood glucose concentration
set point
the normal value or range of values for a particular parameter
negative feedback
a machanism that detects a move away from the set point
type 1 diabetes
a condition in which insufficient insulin is secreted by the pancreas, so that blood glucose concentration is not controlled
sweat gland
a structure found in the skin of mammals, which secretes a watery fluid onto the skin surface to reduce body temperature
hypothalamus
part of the brain that is involved in the control of body temperature
vasoconstriction
narrowing of arterioles, caused by the contraction of the muscle in their walls
vasodilation
widening if arterioles, caused by the relaxation of the muscle in their walls
