digestive system Flashcards
mechanical digestion
to physically break down food
- chewing
- churning (stomach)
- emulsion
chemical digestion
0to chemically break down macromolecules by enzymes
oral cavity
site of food intake
- mechanical digestion (mastication) and
- chemical digestion (salivary amylase)
- tongue moulds food into a bolus
salivary glands
breaks down carbohydrates, lubricates food, and keeps the mouth moist
esophagus
moves food from the mouth to the stomach
pharynx
chamber in the back of the mouth where the nose passageway (trachea) and the mouth passageway (esophagus) meet.
epiglottis
closes the trachea when swallowing
the flap of epithelial opens so gases can get to the lungs
peristalsis
wavelike contractions of smooth muscle that move food down the esophagus to the stomach despite gravity
(peristaltic action)
stomach
food storage and where mechanical and chemical (protein only) digestion takes place.
the cardiac and pyloric sphincter
cardiac- moves food from the esophagus to the stomach
pyloric- regulates movement from the stomach to the duodenum (small intestine)
fundus and pylorus
fundus- upper part of the stomach that produces inactive enzymes
pylorus- lower part where enzymes become active and take part in chemical digestion
3 layers of muscle of the stomach and function
longitudinal, circular, and oblique
allow the stomach to churn the food
gastric glands
in the wall of the stomach that produce hydrochloric acids, mucous, and pepsinogen
mucous
lines the inner stomach and prevents breakdown of the stomach by acids/enzymes
parietal cells
(hydrochloric acid)
provides a proper pH, kills bacteria separate protein
