Serosa(outer most): Allows GI to glide across other surfaces. Loose connective tissue and Mesothelium(epithelium that derives from mesoderm)

Muscularis Externa:

-Outer longitudinal muscle:

-Myentric Plexus:Key in coordinating contractile activity. Contain ganglia and nerve fibers.

-Inner circular muscle:

Submucosa:

-Dense Irregular connective tissue

-Submucosal Plexus: Contains gland Blood vessels and ganglia.

Mucosa:

-Muscularis Mucosa:

-Lamina Propria: Looses connective tissue

-Epithelium/Mucus membrane:

Distinguish nutrients and Poisons

• releases Amylase: breaks down carbs into sugars. (only thing that begins to get digested in mouth)
• adds water

• Mix food with saliva.
• Position food between teeth.

• Transfer food mixture to esophagus

Mucosa: Protects against invasion and autodigestion.

Mucosal(gastric) glands: Add acid and enzymes to chyme(not called food anymore). Further breakdown.

Muscularis: Mixes contents. Transfers to small intestines.

Mucosa: Absorbtion of Nutrients AND some water. Protects against invasion and autodigestion.

Opening of Bile Duct: Recieves bile(detergent) from liver or gall bladder(storage area). Emulsifies fat, increases surface area for enzyme attack.

Opening of Pancreatic Duct: Recieve hydrolytic enzymes that attack and further break down nutrients.

Muscularis: transfers contents to large intestine.

Mucosa: Absorption of WATER(make contents hard). Protect against invasion.

Mucosal Goblet cells: Reduce friction, ease transport of dehydrated waste.

Muscularis: Transfer to anal canal.

Mucosa: Nonkeratinized stratified squamous epithelium. Lamina Propia is vascularized and has no muscularis mucosae. Also loose connective tissue.

Submucosa: Dense irregular connective tissue. Vascular with some salivary glands.

Muscularis externa:

-Skeletal Muscle: Lips, cheek, tongue, soft palate, oropharynx, and floor.

-Bone: replaces muscle layer in hard palate and under gums(gigiva)

Facial thin skin: outside part of the lip. Has hair folicles.

Vermilion border: Where the lips touch each other. Thin epithelium. Redich color because of capillaries underneath can be seen.

Oral Mucosa: Thick Keratinized squamous epithelium.

Circumvallate Papillae: Biggest(least numerous), located near the V-shaped groove near the back of the tongue. Taste buds are located on its sides. Have von Ebner's glands which prevent particles from getting stuck in the crevises of the papillae.

Fungiform Papillae: Occure sigularly and resemble mushroom. Taste buds are at the top of it. Has something to do with pain.

Foliate Papillae: Taste buds on the sides. Occur in rows. Deep epithelial ridges.

Filiform papillae: NO TASTE BUDS. Most numerous. Have some keratin. Look sharp and ragged.

Rod Shaped 

Cell Type: Ameloblast. Oral Ectoderm. only part that comes from oral ectoderm.

Composition: Hydroxyapatite, Enamelins, Amelogenins.

Relative Hardness: Hardest

Location: Covers crown

 Tubules

Cell Type: Odontoblast(neural crest)

Composition: Hydroxyapatite, Type I Collagen.

Relative Hardness: Harder than Cementum, softer than enamel.

Location: Surrounds entire pulp.

Bonelike

Cell Type: Cementoblast(neural crest)

Composition: Hydroxyapatite, Type I collagen

Relative Hardness: hard like bone, but softer than both enamel and dentin.

Location: Covers root

• Nonkeratinized stratified squamous epithelium
• Long epithelial ridges
• Dense lamina propia

• Bone under tooth
• Always primary bone and easy to remodel

• Between aveolar bone and cementum.
• Type I Collagen fibers and dense ct.
• Sensitive to nutritional (Vitamin C, protein) deficiency

Mucosa:

Submucosa: has glands

Muscularis Externa: skeletal muscle. voluntary control of swallowing.

Upper GI: skeletal/voluntary

Mid GI: skeletal and smooth

Lower GI: smooth