Final: Nutrition, Digestion, and Absorption Slides Flashcards
Functions of digestive system (2)
-Chemically breaks down food we eat
-Absorbs the food to transfer it to cells
(making nutrients in food accessible to cells)
Processes of digestive system (4)
Motility, secretion, digestion, absorption (in that order)
What happens during motility?
Food moves through organs at appropriate speed (propulsive), and food is mixed
Purpose of mixing food during motility
Promotes digestion and mixing with enzymes, and facilitates absorption
What are proteins, carbohydrates, and lipids broken down into?
Proteins: amino acids
Carbs: glucose, fructose, galactose (monomers)
Lipids: fatty acids
What happens during secretion in the digestive system?
Digestive organs release many substances (enzymes, lubricants, etc.)
What happens during process of digestion?
Food broken down into smaller pieces so it can be absorbed
What are the main organs of the digestive system? (7)
Mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
What are the accessory organs of the digestive system? (4)
Salivary glands (3), liver, gall bladder, pancreas
Difference between main and accessory organs of the digestive system
Food only physically passes through the main organs, while accessory organs release substances into the main organs
Types of salivary glands and location (3)
- Sublingual (under tongue)
- Submandibular (under jaw)
- Parotid (by ears)
What enzymes does saliva contain? What are their functions?
Salivary amylase: starts digestion of carbs
Lingual lipase: starts lipid breakdown (mostly insignificant effect)
Functions of saliva in the mouth (5)
- Facilitates swallowing by lubricating food particles
- Provides antibacterial action by releasing lysozymes (break down bacteria)
- Saliva dissolves food particles to stimulate taste buds
- Aids in speech
- Neutralizes ingested acid (saliva usually basic)
Function of esophagus (and how it moves food)
Muscular tube (smooth muscle) that connects pharynx and stomach; peristaltic waves push food down (no actual digestion occurs)
Structure of esophagus
- Upper esophageal sphincter is located proximally (beginning)
- Lower esophageal sphincter is located distally (end)
Functions of stomach (3)
- Starts digestion of proteins
- Gastric mixing and gastric emptying
- Temporary hold for food that is consumed
Structure of stomach
- Gastroesophageal sphincter: opening from esophagus
- Pyloric sphincter: gateway to small intestine
- Rugae: folds that increase surface area
What happens during gastric emptying?
Pyloric sphincter open: peristaltic contractions move food into duodenum
What happens during gastric mixing?
Pyloric sphincter closed: food mixed inside stomach, cannot enter duodenum