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30 Cards in this Set
- Front
- Back
DIGESTIVE SYSTEM
Five Basic Processes |
Ingestion - eating
2. Movement of the food along the G.I. tract. 3. Digestion- chemical and mechanical breakdown of food. 4. Absorption of the breakdown products into the lymphatic and circulatory systems. 5. Defecation - elimination of undigested substances. |
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alimentary canal
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The Gastrointestinal tract
- extends from the moth to the anus. - 30 feet long (in the cadaver) - accessory structures - aid in digestion - example: teeth, liver, pancreas |
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Histology
- 4 basic layers with subdivisions |
Mucosa, Submucosa, Muscularis, Serosa
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Epithelium
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- in contact with the food
- varies from stratified squamous in esophagus and anal canal to simple columnar in the small intestine |
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Mucosa
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- mucous membrane
- lining of a tract - has 3 sublayers Epithelium, Lamina Propria, Muscularis mucosae |
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Lamina Propria
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- areolar connective tissue
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Muscularis mucosae
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smooth muscle
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Submucosa
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- binds mucosa to underlining smooth muscle layer
- made of areolar connective tissue - contains ANS supply to muscularis mucosae called Submucosal Plexus (Plexus of Meissner) |
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Muscularis
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- in mouth, pharynx and esophagus is skeletal muscle
- in the rest of the tract is smooth muscle. - usually contains 2 sheets (stomach has 3) - inner circular - outer longitudinal - contains the major nerve supply to the major nerve supply the Myenteric Plexus (Plexus of auerbach) controls motility |
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Serosa
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- serous membrane
- made of connective tissue and epithelium |
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Mouth
- oral or buccal cavity - anatomy |
cheeks, labial frenulum, lingual frenulum, fauces, hard palate, soft palate
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cheeks
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help hold food in place between molars
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labial frenulum
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- mucous membrane fold
- attaches lips to gums |
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lingual frenulum
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attaches tongue to base of oral cavity
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fauces
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opening between the oral cavity and the oropharynx (throat)
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hard palate - made from:
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palatine processes of the maxilla and horizontal plates of the palatine bones
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soft palate
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arch between oral pharynx and nasal pharynx
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Tongue
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- holds food in place over molars (with cheeks) so food can be masticated
- moves food to back of mouth for swallowing and is involved in swallowing - 2 sets of muscles Extrinsic muscles, Intrinsic muscles |
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Extrinsic muscles
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the origin of the muscle is outside of the tongue. Functions; aids in chewing and swallowing and moves tongue in and out and from side to side.
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Intrinsic muscles
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- origin and insertion of muscles is inside the tongue itself
- functions - alters the shape of the tongue - speech and swallowing |
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glands on the surface of the tongue secrete ________
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Lingual Lipase
-digest triglycerides into fatty acids and monoglycerides |
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Salivary Glands
- buccal glands secrete some_______ - 3 pairs of major salivary glands |
saliva
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Salivary Glands
- 3 pairs of major salivary glands |
Parotid Salivary glands, Submandibular Salivary glands, Sublingual Salivary gland
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Parotid Salivary glands
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- located anterior to the ears
- secrete through parotid duct into the oral cavity by upper second molar - secrete a watery mucous with salivary amylase |
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Submandibular Salivary glands
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- located under the mandible at sides of tongue
- secrete a thicker saliva with mucous and salivary amylase - empty under the tongue |
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Sublingual Salivary gland
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- located under the tongue
- secrete a thick mucous with little salivary amylase - secrete into mouth under the tongue |
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saliva is composed of:
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99.5% water, 0.5% solutes like: ions, gases, urea/uric aid, serum proteins,
lysozyme, salivary amylase |
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Secretion of Saliva
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- 1000 to 1500 ml secreted daily from salivary glands
- under nervous system parasympathetic stimulation from the salivary nuclei in the brain stem |
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secretion of the saliva can be brought about by:
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- food in the mouth
- thought, smell, sound, sight of food. |
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Teeth
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- accessory structures
- aid in masticating food - two dentitions: Deciduous teeth, Permanent teeth |