excretion

    Cards (60)

    • Why is excretion important for the body?
      It maintains metabolism
    • What is excretion?
      Removal of excess toxic waste products
    • Name examples of excretory organs.
      Lungs, kidney, liver, and skin
    • What is metabolic waste made of?
      Carbon dioxide, nitrogenous waste, urea, water, salts, ammonia
    • What do mammals produce as metabolic waste?
      Urea
    • What do fish and birds/insects produce as metabolic waste?
      Fish produce ammonia; birds/insects produce uric acid
    • What are bile pigments?
      Breakdown of hemoglobin from old red blood cells
    • What is urea made of?
      Undigested food and fiber
    • How does the skin act as an excretory organ?
      Sweat contains salts, urea, water, uric acid, and ammonia
    • What happens if metabolic waste products build up in the body?
      Build-up of CO2 and NH3 is toxic
    • What is the role of the liver?
      Breakdown of unwanted substances and production of waste
    • What are hepatocytes?
      Liver cells
    • What do hepatocytes contain?
      Nuclei, Golgi apparatus, folded membrane, and mitochondria
    • What is the difference between the hepatic artery and hepatic vein?
      Hepatic artery carries oxygenated blood; hepatic vein carries deoxygenated blood
    • Describe the internal structure of the liver.
      Hepatocytes, lobes, lobules, sinusoids, hepatic vein, Kupffer cells, bile canaliculi
    • What is the function of bile canaliculi?
      Where bile is produced and secreted
    • Why might blood in the hepatic portal vein contain toxins?
      Blood from the intestine contains toxins after digestion of alcohol
    • What are the functions of the liver?
      Storage of glycogen, detoxification, formation of urea
    • Explain the role of the liver in storing glycogen.
      Hepatocytes convert glucose into glycogen
    • Explain how detoxification works on hydrogen peroxide in the liver.
      Catalase breaks down hydrogen peroxide into oxygen and water
    • What happens when too much alcohol is taken?
      Cirrhosis occurs
    • Explain how detoxification works on alcohol.
      Ethanol is broken down into ethanal and then acetic acid
    • What does NAD do?
      Breakdown fatty acids used in respiration
    • What happens if NAD is used up?
      Breakdown of fatty acids is no longer possible
    • Describe amino acids in the liver.
      Excess amino acids are excreted via deamination
    • What is deamination?
      Removal of an amino group from the amino acid
    • Describe ammonia in the liver.
      Ammonia is converted into urea, which is less toxic
    • What are the products of deamination?
      Ammonia and keto acid
    • What is the function of Kupffer cells?
      Remove bacteria and break down old RBCs
    • What is the function of the hepatic portal vein?
      Brings digestion products from the intestine to the liver
    • What are the kidney tubules called?
      Nephron
    • What does the nephron consist of?
      Bowman's capsule, glomerulus, tubules, loop of Henle, collecting duct
    • What does the filter barrier consist of?
      Endothelial and epithelial cells, basement membrane
    • What is the function of Bowman's capsule?
      Contains the glomerulus and where ultrafiltration occurs
    • What is the function of the glomerulus?
      Knot of capillaries where pressure forces solutes into Bowman's capsule
    • What is the function of endothelial cells of the filter barrier?
      Gaps allow dissolved substances to pass through
    • What is the function of the basement membrane of the filter barrier?
      Prevents large molecules and proteins from entering
    • What is the function of epithelial cells of the filter barrier?
      Podocytes with gaps to let blood pass through
    • What is ADH?
      A hormone that controls water and salt
    • What is ultrafiltration?
      Filtration of blood from glomerulus into Bowman's capsule