Unit 7/8 Flashcards
homeostasis
Process by which a constant internal environment is maintained despite changes in the external environment.
dynamic equilibrium
condition that refralns stable within fluctuating limits
negative feedback
process by which a mechanism is activated to restore conditions to their original state
positive feedback
process by which a small effect is amplified
thermoregulation
maintenance of body temperature within a range that enables cells to function efficiently
hypothalamus
region of the vertebrate’s brain responsible for coordinating many nerve and hormone functions
deamination
removal of an amino group from an organic compound
urea
nitrogen waste formed from two molecules of ammonia and one molecule of carbon dioxide
uric acid
waste product formed from the breakdown of nucleic acids
contractile vacuole
a structure in unicellular organisms that maintains osmotic equilibrium by pumping fluid out from the cell
ureters
tubes that conduct urine from the kidneys to the bladder
urethra
tube that carries urine from the bladder to the exterior of the body
cortex
outer layer of the kidney
medulla
area inside of the cortex
renal pelvis
area where the kidney joins the ureter
nephrons
functional units of the kidneys
afferent arterioles
small branches that carry blood to the glomerulus
glomerulus
high-pressure capillary bed that is the site of filtration
efferent arterioles
small branches that carry blood away from the glomerulus to a capillary net
peritubular capillaries
network of small blood vessels that surround the nephron
Bowman’s capsule
cuplike structure that surrounds the glomerulus
proximal tubule
section of the nephron joining the Bowman’s capsule with the loop of Henle
loop of Henle
carries filtrate from the proximal tubule to the distal tubule
distal tubule
conducts urine from the loop of Henle to the collecting duct
collecting duct
tube that carries urine from nephrons to the pelvis of a kidney
filtration
process by which blood or body fluids pass through a selectively permeable membrane
reabsorption
transfer of glomerular filtrate from the nephron back into the capillaries
secretion
movement of materials, such as ammonia and some drugs, from the blood back into the distal tubule
threshold level
maximum amount of material that can be moved across the nephron
interstitial fluid
fluid that surrounds the body cells