Term
| What are the functions of the digestive system? |
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Definition
| ingestion, movement of food, digestion, absorption, defecation |
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Term
What is mechanical digestion? |
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Definition
maceration by teeth, churning by stomach and small intestines |
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Term
| What is chemical digestion? |
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Definition
| catabolic reactions which break down large molecules into small ones |
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Term
| How is the digestive system organized? |
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Definition
| contains a GI tract (mouth, pharynx, esophagus, stomach, small and large intestines) and accessory structures (teeth, tongue, salivary glands, liver, gall bladder, and pancreas) |
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Term
| What are the 3 layers of the GI tract? |
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Definition
| mucosa, submucosa, muscularis |
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Term
| What kind of tissue is in the mucosa layer? |
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Definition
| it is in direct contact, stratified squamous epithelium in mouth, esophagus, and anus canal. simple columnar epithelium in stomach and intestines= secretion and absorption |
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Term
| What is the muscularis mucosae? |
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Definition
| a thin layer of smooth muscle which undulates, creating peaks and valleys which serve to increase surface area |
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Term
| What is the lamina propria? |
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Definition
is an underlying layer of areolar CT. Supports the epithelium, connecting it to the muscularis mucosae. Contains abundant blood & lymphatic vessels
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Term
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Definition
Areolar CT that binds the mucosa to the muscularis, Highly vascularized, Contains part of the submucosal plexus (Meisnner’s) - autonomic nerve supply to the muscularis mucosae which serves to control secretions
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Term
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Definition
*mouth, pharynx, superior esophagus-composed of skeletal muscle for voluntary movement
*external anal sphincter- composed of skeletal muscle for voluntary defecation
*rest of GI tract except stomach-smooth muscle arranged in 2 sheets=inner sheet of circular fibers, outer sheet of longitudinal fibers
*stomach 3 layers- inner oblique, middle circular, outer longitudinal
*contains myenteric plexus which controls GI tract motility |
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Term
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Definition
| superficial layer of portions of GI tract suspended above the abdominopelvic cavity, composed of CT and epithelium |
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Term
| What is the peritoneum and what does it contain? |
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Definition
| largest serous membrane in body=CT +simple squamous epithelium, parietal & visceral peritoneum, mesentery, falciform ligament, lesser and greater omentum |
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Term
| what does the parietal and visceral peritoneum line? |
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Definition
parietal=lines abdominopelvic cavity
visceral=covers some organs in the cavity and is their serosa |
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Term
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Definition
Mesentery is an outward folding of the visceral peritoneum covering the intestines, binding the intestines to one another & to the posterior abdominal wall
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Term
| what is the falciform ligament? |
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Definition
Falciform ligament is another folding that connects the liver to the anterior abdominal wall & the diaphragm
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Term
| what is the lesser and great omentum? |
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Definition
lesser=suspends the stomach and the duodenum from the liver
greater=drapes over the transverse colon and small intestines (lots of FAT!) |
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Term
| what are the organs of the GI tract? |
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Definition
| mouth, tongue, teeth, pharynx, esophagus, stomach, pancreas, liver, gall bladder, small intestines, large intestines |
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Term
| what is the mouth lines with? |
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Definition
| nonkeratinized squamous epithelium |
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Term
| what is the tongue composed of? |
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Definition
| skeletal muscle covered with mucous membrane |
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Term
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Definition
| projections of the lamina propria covered with epithelium |
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Term
| what are the 3 papillae on the tongue and what do they contain? |
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Definition
filiform=contain no taste buds
fungiform= most contain taste buds
circumvillate= all contain taste buds |
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Term
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Definition
| lubricates, dissolves, and initiates chemical breakdown of food |
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Term
| what are buccal and salivary glands? |
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Definition
buccal=minor glands in the mucous membrane lining the mouth, small amounts of saliva
salivary=major glands lie outside of the mouth, saliva is moved by ducts into the mouth |
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Term
| what are the 3 salivary glands? |
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Definition
Parotid, Submandibular, Sublingual
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Term
| what forms the solute portion of saliva? |
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Definition
| salivary amylase, lingual lipase, lysozyme |
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Term
| what kind of joints are teeth? |
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Definition
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Term
what are teeth composed of and what are their function?
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Definition
| sockets lined with periodontal ligaments(dense CT), 3 portions-crown, neck, root, teeth composed of dentin, dentin of crown covered by enamel, function is mastication- physical digestion of food |
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Term
| what is the pharynx covered with and what is it subdivided into(from mouth to esophagus)? |
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Definition
| stratified squamous epithelium, oropharynx, hypopharynx |
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Term
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Definition
| a mechanism to move food from mouth to stomach |
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Term
| what are the 3 stages of deglutition? |
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Definition
voluntary stage=bolus is moved into the oropharynx
pharyngeal stage=involuntary passage of the bolus through the pharynx into the esophagus
esophageal stage= involuntary passage of the bolus through the esophagus into the stomach |
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Term
| where does the esophagus lie? |
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Definition
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Term
| whats are the layers of the esophagus? |
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Definition
mucosa=stratified squamous epithelium, lamina propia, muscularis mucosae. near stomach mucus glands will appear
submucosa=areolar CT, blood vessels, mucous glands
muscularis=superior third-skeletal, intermediate third-skeletal & smooth, inferior third-smooth
adventita=connective tissue |
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Term
| what are the functions of the esophagus? |
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Definition
| secretes mucus, does not produce digestive enzymes and does not carry out absorption, upper esophageal sphincter regulates passage of food from hypopharynx into esophagus, esophageal stage accomplished by peristalsis |
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Term
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Definition
| involuntary muscle movement |
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Term
| how does peristalsis work in the esophagus? |
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Definition
| contraction of circular muscles propel bolus inferiorly, while longitudinal muscles inferior to bolus contract, widening esophagus in this are to receive bolus. blous is regulated at the esophagus-stomach junstion by the gastroesopageal sphincter |
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Term
| what does the stomach connect? |
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Definition
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Term
| what does the stomach contain? |
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Definition
| cardia, fundus, body, pylorus |
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Term
| what are the 2 parts of the pylorus? |
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Definition
pyloric antrum=connects to body of stomach
pyloric canal=leads to duodenum. pylorus communicates with duodenum via pyloric sphincter |
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