Digestive sys Flashcards
Digestive system
Responsible for ingestion, digestion, absorption, defecation
Breaks down food into nutrients, absorbs them, eliminates them
Digestive organs are divided into
Alimentary canal (GI Tract)
Accessory organs
Alimentary canal (GI tract)
extend from mouth to anus : mouth - pharynx- esophagus- stomach- small intestine- large intestine
Accessory organs
Release secretion into alimentary canal that help digest food
Accessory organs consist of
Salivary glands
Liver
Gallbladder
Pancreas
Digestive sys functions
mechanical digestion: physical break down of food (chewing)
Chemical digestion: enzymatic breakdown of food into smaller molecules
Absorption: passage of nutrients into blood stream
Defecation: elimination of indigestible waste
Mesenteries
Attaches intestine to abdominal walls
Provides support
Stores fat
Supply blood, lymph, vessels, nerves to intestines
Layers of digestive tract
- Mucosa (inner most)
- Submucosa
- Muscularis Externa
- Serosa (outer most)
Peristalsis
Wave like muscle contraction that propels food through GI tract
Segmentation
Mixing movement that churns food w digestive enzymes
What controls movement along the digestive tract?
Myenteric plexus coordinates smooth muscle contraction for peristalsis
How many pairs of salivary glands are there?
3 pairs: Parotid, sublingual, submandibular glands
Functions of the oral cavity
Mechanical digestion: chewing
Chemical digestion: secretion of salivary enzymes
What are the functions of salivary glands?
Lubrication
Bacterial control
Initiation of carb digestion
Salivary glands are composed of
H2O
Electrolyte
Mucus
Enzymes
Antibacterial compounds
Functions of the tongue
Mechanical processing
Taste
Swallowing
Secretion of mucus
Gastric pits/ cell types
Parietal cell: secretes hyaluronic acid + intrinsic factors
Chief cells: secrete pepsinogen
G cells: secrete gastrin
Function of Esophagus
Transport food from pharynx to stomach via peristalsis
Stomach function
Storage: temporarily holds food
Mechanical digestion: churns food into chyme
Chemical digestion: secretes gastric juice
Limited absorption: absorbs H2O, alcohol, some drugs
