Digestive system Flashcards
Digestive tract/alimentary tract or canal
Tube from oral cavity to anus
GI tract
Refers to stomach and intestines
Accessory organs
Primarily glands
Secrete fluids into tract
Ingestion - function
Introduction of food into the stomach
Mastication
Chewing
Increases surface area
Propulsion - function
Two types
Deglutition
Peristalsis
Deglutition
Swallowing
Peristalsis
Moves material through digestive tract
Secretion - function
Mucus - along entire digestive tract to lubricate food
Water - food easier to digest and absorb
Bile - emulsifies fats
Enzymes - chemical digestion
Digestion - function
Mechanical and chemical
Absorption - function
Movement from tract into circulation or lymph
Elimination - function
Waste products removed from body
Defecation
Functions of digestive system
Ingestion Mastication Propulsion Mixing Secretion Digestion Absorption Eliminator
Mixing - function
Wave of smooth muscle relaxation moves ahead of bolus
Wave of contraction of smooth muscle behind bolus
Nervous regulation of digestive system (local)
Enteric nervous system
Coordinates peristalsis and regulates local reflexes
Nervous regulation of digestive system (general)
Coordination with CNS
May initiate reflexes because of sight, cell or taste of food
Primarily parasympathetic
Sympathetic inhibits (muscle contraction, secretion, blood flow to digestive tract)
Chemical regulation of digestive system
Production of hormones (gastrin, secretin)
Production of paracrine chemicals like histamine
Saliva produced by
Compound alveolar salivary glands