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Graphic overview of alimentary canal How are we similar to a tall donut? Introduction to Digestive System
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What is/are the function(s) of the digestive system? What structures are necessary? How does function vary with form? Introduction to Digestive System
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How does this system develop embryologically? _____________ is the epithelial lining of the alimentary canal. ________ splits into _______ and ____________ mesoderm. Splanchnic mesoderm contributes to substance of G.I. Viscera (visceral and parietal peritoneum). Yolk or membrane connection is the _____________ Anterior = ___________ and posterior = _________. Introduction to Digestive System
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What are features of the mouth and oral cavity? _______________in jawed fishes _______________in tetrapod What comprises the cavity? Laterally… the _______ (mucousa, buccinator, hypodermis, dermis, and epidermis) Superiorly… Oral Cavity
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What are features of the mouth and oral cavity? Reptiles have _____________, this channels air from _______ _________ to ________. Anurans can have openings that lead to evaginations of the oral cavity (___________) extending below the phayrnx. Seed eating birds can have a similar evagination (__________) suspended by the mylohyoid. Granivorous mammals can have ______________ http://content.answers.com/main/content/wp/en/thumb/7/7d/240px-Litoria_chloris_calling.jpg http://www.birdandhike.com/Wildlife/Mamm/06Rod/04_Het/Dip_mer/D_mer.htm
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Hard and Soft palates __________________: congenital defect where embryonic tissues fail to fuse What can your palate do for you? Oral Cavity
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Tongue
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What are the functions of the tongue? Bound by the ___________
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What are the functions of the oral glands of tetrapods? * * * Can produce toxins (________ in 4 snake groups, ___________ in lizard) Initiate digestion (_____________) Aid in immunity (_____________) _______________in fish… papa catfishes Oral Glands
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3 paired glands: * * * Scattered small tubular glands How do you salivate? Secrete … Endocrine or Exocrine? Oral Glands
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Teeth Who has teeth and who doesnt? The haves Gnathostomes, amphibians, most reptiles, and mammals (highest specialization). And the have nots Agnathans, modern birds, a few mammals lack teeth. http://www.msnbc.msn.com/id/6445952/ http://i28.photobucket.com/albums/c219/ucfburnsy/platypus.jpg
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Teeth How do teeth develop? Teeth are the derivatives of …
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How do teeth develop? Teeth (and placoid scales) are composed of __________ and a covering of _________________. ______________develop as in growths of ectoderm along the jaws. ______________develop under the future site of each tooth. ______________ deposit dentin. Dental lamina forms _______ __________with ___________ that deposit _____________. Teeth
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Mastication = Which type of digestion? Why? Accomplished via: Types of teeth: * * * * Teeth What is the oral cavity and what does it do?
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How are teeth attached? __________________and ________ keep teeth associated with sockets in mammals (_____________). In some fishes teeth are on the shoulder of the dentary bone (______________) In anurans, urodeles and squamates they are attached to the inner aspect (________________) Many fishes, toothed birds, crocodilians and mammals there is a socket (________________) Teeth
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How do teeth vary? Sharks have a broad basal plate anchored in … Some teeth are adapted for: - crushing shells etc. - Modified to deliver ______ Peak of specialization in… Incisors of rodents and lagomorphs … Missing canines and/or premolars results in a ________ Teeth
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Alimentary Canal Structure
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Stomach
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What are the functions of the stomach? ______________(sometimes this task is given to specialized structures ex. crop). ________________(Gizzard of birds and crocodilians, gastroliths) ________________(which nutrient category?) ____________ and _________ consistency of chyme and _______________ into the small intestine Stomach
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How are the regions of a stomach related to their function? Specific cells responsible for specific components of _______________. Regions with minimal __________________ have esophogeal-like epithelia. Regions with abundant zymogen and parietal cells have _________________ ___________ is important muscular sphincter Stomach
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What are the structures as related to human anatomy? Stomach
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What about ruminates? _________ are sacs/caeca that facilitate the chemical digestion of the tough polysaccharide cellulose. The necessary enzyme is _________ produced by anaerobic bacteria. Returning the _____________ back to the mouth facilitates additional mechanical digestion. Temporary storage is in the ___________ and the glandular stomach is the ____________ Stomach
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How is intestine structure related to function? Chemical digestion = secreted by the ________ and those associated with the epithelium Abosorption = Transportation = ___________ maintained by mucous glands Intestines
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Contains features such as: Why? Functions include: Whats the internal anatomy of the small intestines? Digestive enzymes in association w/ microvilli: Intestines
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Digestive glands
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_______________: formed in lobules, drains out hepatic ducts, secreted and/or stored in gall bladder. ____________: can store nutrients (glycogen, vitamins, fats) ________________ ____________: metabolically swapped ____________ ____________ ____________ Whats the digestive role of the Liver? What are gall stones? Liver and Pancreas
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Pancreas http://www.vetmed.vt.edu/education/Curriculum/VM8054/Labs/Lab20/IMAGE S/PANCREATIC%20ISLET%203%20SMALL.jpg
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* Normal flora can produce:* Capable of mass movements What are the functions of the colon? Colon
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How does it (defecation) happen? Diarrhea & Constipation __________results in defecation reflex w/c is a contraction of _______________ and ________ of internal anal sphincter. If ignored reflex is _________. If acted upon, voluntary actions result in ________. Colon
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