bio digest

• almost all organisms depend on this for food


  the sun's radiant energy
• autotrophs 


  convert water and CO2 using the Sun's energy into organic sugars
• heterotrophs


  organisms that cannot make their own food / consume organic sugars made by autotrophs
• autothrophic nutrition

  > can make own food

  > "producers"

  > composed of plants

  > can be photoautotrophic or chemoautotrophic
• primary source of food for all living things

  plants
• photoautotrophic

  using sun and solar energy / all green plants
• chemoautotrophic


  using chemicals
• peristalsis 


  squeezing action
• tracing

  1. Mouth/Oral Cavity
  2. Pharynx
  3. Esophagus
  4. Stomach
  5. Duodenum
  6. Jejunum
  7. Ileum
  8. Cecum
  9. Ascending Colon
  10. Transverse Colon
  11. Descending Colon
  12. Sigmoid Colon
  13. Rectum
  14. Anus
• heterotrophic nutrition

  > consumers

  > rely on others for food

  > parasitic / saprophytic / holozoic
• parasitic

  obtains food and harms host
• saprophytic

  obtains dead/decaying matter
• holozoic nutrition

  digestion
• digestion

  breakdown of food into usable forms to be easily absorbed by the body
• bulk feeders

  eat large pieces of food / humans
• mechanical digestion

  physical breakdown
• chemical digestion

  using enzymes
• enzymes

  proteins that speed up a chemical reaction
• mouth / oral cavity


  first chamber of digestive tract / where food is captured and digested physically (teeth, tongue, cheek muscles) and chemically (saliva)
• lingual frenulum

  holds tongue
• soft / hard palate

  roof of oral cavity
• uvula

  curtain that closes so no food can go to the nose
• how many teeth does an adult have

  32
• incisors

  cutting, biting
• canines

  tearing
• premolars and molars

  grinding, crushing
• enamel

  hard outer layer
• dentine

  soft filling
• pulp cavity

  central, living pulp supplied with blood vessels and nerves
• tongue


  large, muscular organ that occupies most of the oral cavity
• frenulum

  thin fold of tissue
• 3 pairs of salivary glands

  parotid, submandibular, sublingual
• enzymes in saliva

  ptyalin, maltase
• ptyalin

  salivary amylase / carbs or starches into maltose
• maltase

  maltose into glucose
• pharynx (throat)

  > swallowing

  > a musculomembranous tube

  > common passageway of both food and air
• esophagus

  > flexible tube carrying food only

  > mechanical digestion only

  > peristalsis is present
• stomach

  > expansible muscular sac (2-4 liters)

  > retains food with the help of a pyloric sphincter

  > has rugae

  > both chemical and mechanical digestion
• rugae


  folds in the stomach / allows stomach to expand / wavelike projections
• functions of stomach

  > store food and release to small intestine

  > mechanical digestion

  > chemical digestion