Digestion Flashcards
1
Q
Pic
A
Pic
2
Q
6 basic processes
A
- Ingestion: taking in food and liquid
- Secretion: of water, acid, buffers, and enzymes
- Mixing and propulsion: alternating contractions and relaxation of smooth mm
- Digestion: mechanical and chemical processes to break down ingested food into small molecules
- Absorption: entrance of ingested and secreted fluids, ions, and products of digestion into epithelial cells lining the lumen of the GI tract
- Defecation: push it out shove it out
3
Q
Organs of GI
A
- Upper:
- mouth - pharynx - esophagus - stomach - Lower:
- small - large intestines - Accessory:
- salivary glands (parotid, submadibular, sublingual) - tongue - teeth - liver - gallbladder - pancreas - vermiform appendix
4
Q
Pic
A
Pic
5
Q
Pic
A
Pic
6
Q
Lips
A
Keep food in the mouth while being chewed
- help to sense temperature and texture of food before it enters the mouth
- needs to form many speech sounds
7
Q
Cheeks
A
- lateral boundaries of the oral cavity (keeps food between the teeth)
- lined by mucous membrane
- contain mucous-secreting glands
8
Q
Hard and soft palate
A
The roof of the mouth
- Hard palate: 2 maxillae and 2 palatines
- Soft palate: mm arranged in arch
- uvula: hangs down form the soft palate arch in the midline; it rises during swallowing to close off the nasopharynx from the food
9
Q
Pic
A
Pic
10
Q
Tongue
A
Taste buds
- also includes lingual glads that secret lipase
1. Extrinsic: - tongue muscles
- important in deglución/swallowing and speech
2. Intrinsic mm - alter the shape and size of the tongue
11
Q
Lipase
A
Breaks down triglycerides into fatty acids and diglycerides
12
Q
Pic
A
Pic
13
Q
Salivary glands
A
Saliva is the first of the digestive juices to contact food
- parotid glands: near the ear underlying the masseter muscle
- submadibular glands: on the floor of the mouth just under the mandibles
- sublingual glands: on the floor of the mouth; ducts enter beneath the tongue
14
Q
Pic
A
Pic
15
Q
Teeth
A
- Pulp: soft, fibrous connective tissue with vessels and nerves (in the core)
- Dentin: hard, mineralized connective tissue similar to bone (forms the body of the tooth)
- Cementum: hard, mineralized connective tissue similar to bone (coat around the root of the tooth and helps connect to the jawbone)
- Enamel: hard, mineralized connective tissue; harder than bone (covering exposed tooth surface)
16
Q
Pic
A
Pic
17
Q
Pharynx
A
- Deglutition: act of swallowing
- Bolus: rounded mass of food
- only the terminal part of the pharynx is involved in digestion
- bolus enters the oropharynx then into the esophagus
18
Q
Esophagus
A
- collapsible muscular tube about 25 cm long
- begins at the inferior aspect of the neck and enters the mediastinum anterior to the vertebral column
- pierces the diaphragm through an opening called the esophageal hiatus
- upper eso sphincter: skeletal mm
- lower eso sphincter: smooth mm
19
Q
Hiatal hernia
A
The stomach protrudes up thought the esophageal hiatus above the diaphragm
20
Q
Stomach
A
Lies just below the liver and the diaphragm
- distensión after meals, food processed slowly
- usually holds up to 1-1.5L
1. Fundus: enlarged main upper portion
2. Body: large middle portion
3. Pylorus: lower part
21
Q
Pyloric sphincter
A
- regulate passage of material at both stomach openings
- controls outlet of pyloric portion into duodenum
22
Q
GERD
A
Gastroesophageal disease
- the backward flow of stomach acid up through the lower esophageal sphincter and into the lower part of the esophagus
- can cause heartburn
23
Q
Stomach wall (mucosa)
A
4 layers:
- Mucosa: thick layer of simple columnar epithelium lining the stomach cavity
- designed for the production of digestive acids and enzymes
- epithelial lining has rugged marked by gastive pits (deep clefts that increase the stomachs surface area)
- gastic glands: found in the gastric pits, secrete most of the gastric juices
- chief cells: secrete the enzymes of juice
- parietal cells: secrete hydrochloride acid and produce intrinsic factor neede for vitamin B12 absorption in small intestine
- endocrine cells: secrete gherkin (hormone to increase appetite - hypothalamus) and gastrin ( influences digestive functions)