digestive system Flashcards
functions
ingestion
secretion
mechanical processing
digestion
absorption
defeacation
ingestion
digestive tract via the oral cavity
An active process involving conscious choice and decision-making
secretion
non-specific defence against the corrosive effects of digestive acids and enzymes
water, acids, enzymes, buffers, and salts from the epithelium of the digestive tract and glandular organs into the digestive tract
mechanical processing
Physical breakdown of food into smaller particles that makes materials easier to propel along the digestive tract
Mixes the food with secretions and increases the surface area of the food,
digestion
Chemical breakdown of food into small organic fragments suitable for absorption by the digestive epithelium
absorption
The movement of organic molecules, electrolytes (inorganic ions), vitamins, and water across the digestive epithelium, into the interstitial fluid
defacation
Elimination of wastes, indigestible substances, bacteria, dead cells from the body.
4 layers of digestive tract
muscosa
submucosa
muscularis
serosa
mucosa
inner lining where The locations where absorption occurs,
moistened by glandular secretions
submucosa
Dense, irregular connective tissue beneath the mucosa
Has numerous blood vessels and lymphatic vessels
muscularis
Dominated by smooth muscle cells
The inner circular layer is essential for agitation and in the formation of valves
The outer longitudinal layers of muscle is essential for mechanical processing
serosa
Covers the muscularis externa along most portions of the digestive tract
oral cavity
lubrication by mixing with mucus and saliva
mechanical digestion through the actions of the teeth, tongue and palatal surfaces
-initiation of carbohydrate digestion by salivary amylase
- initiation of lipid digestion by lingual lipase
salivary glands
lysozyme: kills bacteria
- enzymes: salivary amylase and lingual lipase
Saliva:
- lubricates the food and helps combine materials in the mouth with the digestive enzymes
pharynx
passageway for solid food, liquid and air. Swallowing is the process that allows for a substance to pass from the mouth