Biology Test 3

  1. Mucosa
    • Innermost layer
    • all nutrients must cross the mucosa to enter the blood
  2. Submucosa
    • layer of connective tissue containing blood vessels, lymph vessels, and nerves.
    • components of food that are absorbed across the mucosa enter the blood and lymph vessels of this layer.
  3. muscularis
    • responsible for motility or movement
    • consists of two or three sublayers of smooth muscle
    • inner sublayer oriented in circular fashion around the lumen
    • outer sublayer arranged lengthwise.
  4. serosa
    • outermost layer of the gastrointestinal tract wall
    • thin connective tissue surrounds and protects the three layers
  5. sphincters
    rings of circular smooth muscle that may be between organs
  6. Layers of the GI tract
    Image Upload 1
  7. Digestive System Processes
    1) Mechanical Processing and Movement
    Chewing, mixing, propelling
  8. Digestive System Processes
    2) Secretion
    fluid, digestive enzymes, acid, alkali, bile, and mucus are secreted into GI tract
  9. Digestive System Processes
    3) Digestion
    breakdown food to smallest absorbable units
  10. Digestive System Processes
    4) Absorption
    through mucosa into blood or lymph vessels
  11. Digestive System Processes
    5) Elimination
    undigested material is eliminated form the body
  12. Bolus
    food that has been chewed into a mass
  13. Peristalsis
    • Propels food down the GI tract by wave like muscle contractions
    • mainly in esophagus
    • Image Upload 2
  14. segmentation
    • mixes food by muscles contracting and relaxing
    • mainly in small intestine
    • Image Upload 3
  15. The Mouth
    • begins digestion
    • -teeth
    • -tongue
    • -saliva
  16. swallowing
    • delivers food to stomach
    • -voluntary: tongue pushes bolus into pharynx
    • -Involuntary: receptors stimulated by presence of food in pharynx
  17. epiglottis
    closes opening to trachea when food is present
  18. pharynx
    common passage way for air, food, and liquid
Card Set
Biology Test 3
biology test 3