Chapter 17: Digestive System Flashcards
digestion
mechanical & chemical breakdown of foods into forms that cell membranes can absorb; two types
digestive system
organs of digestive system carry out mechanical & chemical digestion, as well as ingestion, propulsion, absorption, & defacation
2 portions of digestive system
- alimentary canal
- accessory organs
alimentary canal
organs that extend from mouth to anus; food passageway
accessory organs
organs that empty secretions into alimentary canal; food does not pass through
how long is alimentary canal?
about 8m long; muscular tube
layers of alimentary canal (4)
- mucosa (inner)
- submucosa
- muscularis
- serosa
mucosa
epithelium, connective tissue, smooth muscle; protection, secretion, absorption
submucosa
loose connective tissue, blood vessels, lymphatic vessels, nerves; nourishes surrounding tissues, transports absorbed materials
muscularis
smooth muscle cells in circular & longitudinal groups; movements of tube & its contents
serosa (outer)
epithelium, connective tissue; protection, lubrication
where are all 4 layers of the alimentary canal able to be seen?
small intestine
2 types of movement in the alimentary canal
- mixing
- propelling
mixing movement
- muscles in small sections contract rhythmically
- does not move material in one direction
- important to chemical digestion, stomach
propelling movement
- moves materials in one direction