Week 10 - Digestive System Flashcards
6 integrated processes of the digestive system
- Ingestion
- Mechanical digestion and propulsion
- Chemical digestion
- Secretion
- Absorption
Defecation
Define ingestion
when food enters oral cavity
Define mechanical digestion and propulsions
Crushing and shearing of food
Define chemical digestion
- Chemical breakdown of food into small organic fragments for absorption by digestive epithelium
Define secretion
Release of water, acids, enzymes, buffers and salts
Define absorption
Movement of organic molecules, electrolytes, vitamins, minerals and water
Define defecation
Elimination of waste from body
Define myenteric plexus
Network of parasympathetic ganglia, sensory neurons, interneurons, and sympathetic postganglionic fibers
Define segmentation
Cycles of contraction that churn and fragment the bolos, mixing contents with intestinal secretions
Functions of the oral cavity
Sensory analysis
Mechanical digestion
Lubrication
Limited chemical digestion
Functions of the tongue
Mechanical digestion Manipulation to assist chewing
Sensory analysis
Secretions of mucus
Define mastication
Chewing
3 regions of the pharynx (throat)
Naso, oro, laryngo: pharynx
Function of the esophagus
Conveys food and liquids to stomach
Define deglutition
Swallowing
Define microbiome
Microbes (bacteria, fungi, viruses) that live in and on the human body
3 vitamins important for digestion
Vitamin K, b5 and biotin
3 functions of the stomach
Temporary storage
chemical and mechanical digestion
Define chyme
Partially digested food mixed with acidic secretions of stomach
what do G cells produce
and D cells release
G = Gastrin D = Somatostatin
3 phases of gastric activity regulation
- Cephalic
- Gastric
- Intestinal
Function of endocrine cells of pancreatic islets
Secrete insulin and glucagon into bloodstream
Function of exocrine cells
Secrete alkaline pancreatic juice into small intestine
Function of pancreatic alpha
Breaks down starches
Function of pancreatic lipase
Breaks down certain complex lipids
Function of nucleases
Break down RNA or DNA
Function of proteases and peptidases
proteases = break apart large protein complexes Peptidases = break small peptide chains into amino acids
3 categories for the function of the liver
- Metabolic regulation
- Hematological regulation
- Bile production
Bile salts function
Break apart lipid droplets
Define enterohepatic circulation
Cycling of bile salts between liver and small intestine