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
mixing is also referred to as…
segmentation
propelling is also referred as…
peristalsis
what helps innervate the alimentary canal?
branches of the sympathetic and parasympathetic divisions of ANS
submucosal plexus
controls secretions
myenteric plexus
controls motility
parasympathetic impulses
increase activities of digestive system
sympathetic impulses
inhibit digestive actions
mouth
- mastication
- functions as organ of speech & sensory reception
- surrounded by lips, cheeks, tongue, palate
- includes oral cavity and vestibule
salivary amylase
begins chemical digestion of carbs
cheeks
contain muscles for chewing & facial expression; inner lining of stratified squamous (moist)
lips
sensory receptors judge temp and texture of food; boundary between skin & mucous membrane inside mouth
parts of tongue (3)
- lingual frenulum
- papillae
- lingual tonsils
lingual frenulum
connects tongue to floor of mouth
papillae
projections that move food, contain taste buds
lingual tonsils
lymphatic tissue masses on root of tongue
palate
- consists of hard & soft
- uvula extends from the soft palate
palatine tonsils
lymphatic masses on sides of tongue
pharyngeal tonsils
adenoids; lymphatic tissue on posterior wall of pharynx
teeth
20 primary (deciduous)
32 secondary (permanent)
salivary glands
- secrete saliva
- moisten food particles & bind them together
- dissolves food so it can be tasted
- saliva contains enzymes and bicarbonate ions
3 pairs of major salivary glands
- parotid
- sublingual
- submandibular
cavity
dental caries
gomphosis
joint where teeth interlock