๐Ÿ’จ 1.2 Digestion and Mechanisms (23-40)

Cards (45)

  • What is the process of mechanical disruption of food called?
    Mastication
  • Where does mechanical disruption of food begin?
    In the mouth with chewing
  • What processes continue in the stomach during digestion?
    Initiation of protein and lipid enzymatic digestion
  • What is necessary for solids greater than 2mm in diameter?
    They do not pass through pylorus
  • In what form are lipids consumed?
    As triglycerides
  • What is absorbed by the small intestine from lipids?
    Fatty acids and monoglycerides
  • What are amino acids present in food as?
    Proteins and large peptides
  • What does the small intestine absorb from proteins?
    Only amino acids and small peptides
  • What carbohydrates are present in the diet?
    Starch, disaccharides, and monosaccharides
  • How are carbohydrates absorbed in the small intestine?
    As monosaccharides
  • What is required for most dietary carbohydrates before absorption?
    Chemical digestion
  • What initiates the digestive processes for carbohydrates and lipids?
    Salivary and lingual enzymes
  • What enzyme is responsible for carbohydrate digestion?
    Amylase
  • What enzyme is responsible for lipid digestion?
    Lipase
  • Where is protein digestion initiated?
    In the stomach by gastric proteases
  • What primarily causes lipid digestion in the stomach?
    Lingual lipase that is swallowed
  • What does carbohydrate digestion NOT involve?
    Secreted gastric enzymes
  • Where is digestion completed?
    In the small intestine
  • What are the pancreatic enzymes critical for digestion?
    Lipase, chymotrypsin, and amylase
  • What do brush border enzymes complete digestion of?
    Carbohydrates and proteins
  • What is digestion by brush border enzymes referred to as?
    Membrane digestion
  • What is the daily dietary fluid intake?
    1.5 to 2.5 L/day
  • What is the fluid load presented to the small intestine daily?
    8 to 9 L/day
  • What mechanisms contribute to digestion?
    Endocrine, neural, and paracrine mechanisms
  • What does the endocrine mechanism involve?
    Release of a transmitter into blood
  • What stimulates the release of gastrin?
    Protein in the stomach
  • What does gastrin stimulate in the stomach?
    H+ release from parietal cells
  • What does the neural mechanism involve?
    Activation of nerves and neurotransmitters
  • What neurotransmitter is released by the vagus nerve?
    Acetylcholine (ACh)
  • What does acetylcholine (ACh) release from parietal cells?
    H+
  • What does the paracrine mechanism involve?
    Release of a transmitter affecting adjacent cells
  • What does histamine stimulate in the stomach?
    H+ release from neighboring parietal cells
  • What are the primary roles of the gastrointestinal tract (GIT)?
    Digesting and absorbing nutrients
  • What is another role of the GIT?
    Excreting waste material
  • What does fecal material consist of?
    Nondigested food products and colonic bacteria
  • What are some excretory products of the GIT?
    Heavy metals and organic anions
  • What is the major route of excretion for heavy metals?
    In bile
  • What is excreted in bile?
    Several organic anions and cations
  • How much fluid does the small intestine secrete daily?
    Approximately 1 L/day
  • Where is water reabsorbed in the GIT?
    In small and large intestine