Graphic overview of alimentary canal How are we similar to a tall donut? Introduction to Digestive System.

Graphic overview of alimentary canal

How are we similar to a tall donut?

Introduction to Digestive System

What is/are the function(s) of the digestive system?

What structures are necessary?

How does function varywith form?

Introduction to Digestive System

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

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

Oral CavityWhat 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

Hard and Soft palates

__________________:congenital defect where embryonic tissues fail to fuse

What can your palate do for you?

Oral Cavity

Tongue

Tongue

Tongue

TongueWhat are the functions of the tongue?

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• Bound by the ___________

What are the functions of the oral glands of tetrapods?

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Can produce toxins (________ in 4 snake groups, ___________ in lizard)

Initiate digestion (_____________)

Aid in immunity (_____________)

_______________in fish… papa catfishes

Oral Glands

3 paired glands:***

Scattered small tubular glands

How do you salivate?

Secrete …

Endocrine or Exocrine?

Oral Glands

TeethWho has teeth and who doesn’t?

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

TeethHow do teeth develop?

Teeth are the derivatives of …

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

Teeth

Mastication = Which type of digestion? Why?Accomplished via:

Types of teeth:****

TeethWhat is the oral cavity and what does it do?

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 thereis a socket (________________)

Teeth

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

Teeth

Alimentary Canal Structure

Stomach

Stomach

Stomach

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

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

What are the structures as related to human anatomy?

Stomach

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

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

Contains features such as:

Why?

Functions include:

What’s the internal anatomy of the small intestines?

Digestive enzymes in association w/ microvilli:

Intestines

Digestive glands

_______________: formed in lobules, drains out hepatic ducts, secreted and/or stored in gall bladder.____________: can store nutrients (glycogen, vitamins, fats)________________ ____________: metabolically “swapped” ____________________________________

What’s the digestive role of the Liver?

What are gall stones?

Liver and Pancreas

Pancreas

http://www.vetmed.vt.edu/education/Curriculum/VM8054/Labs/Lab20/IMAGES/PANCREATIC%20ISLET%203%20SMALL.jpg

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Normal flora can produce:

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Capable of mass movements

What are the functions of the colon?

Colon

How does it (defecation) happen?

Diarrhea & Constipation

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• __________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