excretion

• excretion


  removal of toxic materials, the waste products of metabolism and excess material
• metabolism


  chemical processes going on in the body
• egestion


  removal of undigested food
• urea


  excess amino acids (waste products) produced in the liver
• lungs


  excrete carbon dioxide as waste product of respiration
• kidney


  excretes excess water, sals and nitrogen waste as urea by producing urine via osmoregulation
• skin


  excretes excess water and salts through sweat glands by producing sweat
• liver


  breaks down excess amino acid to produce ammonia (toxic) and then convert to urea (less toxic)
• cortex


  outer layer packed with nephrons that filters the blood
• medulla


  middle layer that has tubes carrying filtered waste to the centre of the kidneys
• pelvis


  area where all collecting ducts come together and connect with the ureter
• ureter


  transport urine to the bladder
• nephrons


  filtration unit in the kidney made of kidney tubules
• ultrafiltration


  where the filter seperates different sized molecules under pressure
• reabsorption


  molecules and ions which are required by the body are taken back from the nephron
• waste release


  waste products to be excreted travel to the ureter and down to bladder
• osmoregulation


  keeping water levels constant
• homoestasis


  process by which the internal systems are maintained at equilibrium despite external conditions
• ADH


  hormone that controls osmoregulation
• permeability


  how much water can be absorbed