Term
| What are the alimentary canal organs that make up the digestive tract? |
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Definition
| -The oral cavity, pharynx, esophagus, stomach, small intestine, and large intestine. |
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Term
What are the acessory organs that make up the digestive tract? |
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Definition
| -Teeth, tongue, salivary glands, liver, and pancreas. |
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Term
What are the functions of the digestive organs? |
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Definition
1. Ingestion
2. Mechanical processing
3. Propulsion and peristalsis: movement of materials through the digestive system
4. Digestion: chemical process, breakdown of food into small molecules for absorption by intestinal epithelium
5. Secretion :(water, buffers, enzymes, acids, by accessory glands)
6. Absorption
7.Excretion (defecation)
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Term
| Name the layers of lining of the digestive tract. |
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Definition
| Mucosa, Submucosa, Muscularis Externa, Serosa |
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Term
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Definition
-secretes mucus, enzymes, and hormones
-absorbs nutrients, vitamins, electrolytes, water
-protects against pathogens
-epithelial lining (simple columnar epithelium, lined with straitified squamous epithelium)
-lamina propria |
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Term
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Definition
-layer of dense connective tissue that surrounds the mucularis mucosae. contains larger blood vessels and lympathic vessles, lymph nodules, and nerve fibers.
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Term
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Definition
-Smooth muscle layer; inner circular and outer longitudinal layers.
-Responsible for segmentation and peristalsis.
-Nerve ganglion
Segmentation is the churning or mixing movement within a portion of the tract. It does not push materials in any one direction. |
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Term
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Definition
-Outermost membrane lining, loose CT and flattened epithelium, Adventita is the same as serosa but without epithelial layer, it allows organs to blend with their surrounding structures.
-Intraperitoneal organs are covered by the serosa. |
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Term
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Definition
| serous membrane covers the organs |
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Term
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Definition
| lines the inner surface of the body wall |
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Term
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Definition
connect parietal and visceral, portions of the digestive tract are suspended within the mesenteries.
-double layers of peritoneum that extend to the digestive organs from the body wall
-provide access route for nerves, blood, and lymphatic vessels.
-holds organs in place and stores fat
-lesser omentum: stomach and liver
-falciform ligament: between liver and superior abdominal wall (diaphragm)
-greater omentum: enormous pouch that extends inferiorly from lateral and anterior walls of the stomach and attaches to transverse colon
-mesentary proper: supports small intestines
-mescolon: supports portion of large intestine (transverse and sigmoid) |
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Term
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Definition
-located within the peritoneal cavity supported by mesenteries.
-stomach, jejunum, ileum, transverse colon, sigmoid colon, liver and gall bladder. |
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Term
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Definition
-located outside of the peritoneal cavity
-duodenum, pancreas, ascending colon, descending colon, rectum, and anal canal. |
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Term
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Definition
-Enteric nervous system refers to the neural network that coordinates the short reflexes of the digestive system. -sensory receptors located in the walls of the digestive tract -myenteric plexus )ganglion of nerves) -local movements and gland secretions
-motor neurons respond by causing smooth muscle contraction or gland secretion. The response to the short reflexes is limited to a limited region within the digestive region. |
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Term
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Definition
-higher level of control that coordinates activities along the entire length of the digestive tract. Involves interaction of nerves from the central nervous system.
-cause large peristatlic movements for movement of materials from one region to the next.
-involves parasympathetic component of the autonomic nervous system. |
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Term
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Definition
-digestive tract produces many hormones by cells called neuroendocrine (B) cells
-first enter the circulatory system for distribution to target organs. |
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Term
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Definition
-local chemicals that affect cells within digestive tract
-local pH and histamine
-these chemicals coordinate a local response to changing conditions within the digestive tract. |
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Term
Functions of the Oral Cavity: |
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Definition
1. analysis of material before swallowing
2. mechanical processing through the actions of teeth, tongue, and palatal surfaces
3. lubrication by mixing with mucus and salivary gland secretions.
4. limited digestion of carbohydrates and lipids
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Term
Anterior boundary of the oral cavity: |
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Definition
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Term
Lateral Boundary of the Oral Cavity: |
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Definition
-cheeks
-roof: hard and soft palate
-floor: tongue and floor of mouth supported by skeletal muscle
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Term
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Definition
-fauces (connects palatoglossal arches and uvula)
-oral pharynx
-palatoglossal arch: extends between soft palate and base of the tongue
-palatopharyngeal arch: extends between the soft palate and oral pharynx
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Term
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Definition
1. mechanical processing of food
2. assistance in chewing and preparation of food for swallowing
3. sensory-taste buds in papillae (gustatory sensation)
4. secretion of mucus: limited lipid digestion
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Term
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Definition
| -allow the tongue to change shape without changing position, occurs during speech |
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Term
Small glands of the tongue produce secretions that contain______. |
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Definition
| -lingual lipase (same substance as pancreatic lipase) |
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Term
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Definition
| -originate on skull or hard palate bones and alter the tongue's position |
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Term
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Definition
-lubricate and moisten food
-dissolve chemicals and good to be tasted
-digest some carbohydrates by excreting amylase
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Term
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Definition
| -watery secretion of ions, antibodies, and enzymes |
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Term
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Definition
| -thick secretion contains glycoproteins and acts as a lubricant |
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Term
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Definition
-largest of salivary glands
-entirely serous produces 25% of total saliva
-secretes a watery mixture rich in salivary amylase and bicarbonate ion. |
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Term
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Definition
-Both serous (4/5th) and mucus (1/5th)
-70% of total saliva volume
-brought into the mouth under the tongue on either side of the lingual frenulum |
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Term
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Definition
-strictly mucus
-5% of saliva volume |
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Term
| How much saliva is secreted a day? |
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Definition
-1 to 1.5 liters
-under CNS neural control
-no hormonal contral
-(autonomic nervous control only)
-parasympathetic: accelerates secretion
-sympathetic: inhibits secretion causing dry mouth |
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Term
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Definition
-non living tissue
-hardest substance in the human body
-covers dentin |
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Term
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Definition
-living tissue, central bulk of teeth
-located in the crown and root
-surround the pulp cavity |
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Term
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Definition
| -living tissue, forms layer over dentin along the roots of the tooth |
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Term
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Definition
| -opening at the end of each root to allow nerve and vascular supply into the pulp cavity |
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Term
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Definition
| -connective tissue that attaches the root of teeth to bony socket |
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Term
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Definition
-incisors (cutting)
-cuspids or canines (tearing)
-bicuspids and molars (crushing and grinding) |
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Term
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Definition
common pathway for solid food, liquids, and air
-initiate the process of swallowing |
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Term
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Definition
-carries food from pharynx to stomach
-passes inferiorly behind the trachea within the mediastinum
-enters adominopelvic cavity through opening called esophageal hiatus (prevents air from entering the esophagus) |
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Term
| gastroesophageal sphincter |
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Definition
-located at the entry to the stomach
-remains contracted to prevent backflow of materials from the stomach into the esophagus
-mucosa is lined by stratified squamous epithelium to prevent abrasion of the esophagus surface by swallowed foods.
1 sec: liquid
5 sec: semisolid
10 sec: solid |
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Term
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Definition
| -swallowing becomes voluntary then involuntary. |
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Term
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Definition
-compression of bolus against hard palate
-retraction of the tongue, which forces bolus into the pharynx
-voluntary |
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Term
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Definition
-bolus move past the palatoglossa and palatopharyngeal arches.
-swallowing reflex produces pharyngeal muscle movement
-respiration stops briefly |
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Term
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Definition
-contraction of the pharyngeal muscles forces the bolus through the entrance of the esophagus
-bolus is then pushed towards the stomach by peristaltic waves |
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