Medicine Notes > Bristol University Medicine Notes > Gastrointestinal (GI) System Notes

Digestion In The Mouth And Swallowing Notes

This is a sample of our (approximately) 4 page long Digestion In The Mouth And Swallowing notes, which we sell as part of the Gastrointestinal (GI) System Notes collection, a 1st (70-80%) package written at Bristol University in 2012 that contains (approximately) 57 pages of notes across 19 different documents.

Learn more about our Gastrointestinal (GI) System Notes

The original file is a 'Word (Docx)' whilst this sample is a 'PDF' representation of said file. This means that the formatting here may have errors. The original document you'll receive on purchase should have more polished formatting.

Digestion In The Mouth And Swallowing Revision

The following is a plain text extract of the PDF sample above, taken from our Gastrointestinal (GI) System Notes. This text version has had its formatting removed so pay attention to its contents alone rather than its presentation. The version you download will have its original formatting intact and so will be much prettier to look at.

Lecture 4 Digestion in the Mouth and Swallowing

Salivary secretion and digestion in mouth o Digestion in the mouth
 No digestion of proteins in the mouth
 Digestion

• Starch-----Amylase: pH7-----> Oligosaccharides
 Motility

• Chewing= Chop food into small pieces, mix with saliva

• Swallowing= Move food to lower parts of GI tract o Glands
 Parotid gland

• Serous (i.e. watery) secretion rich in a-amylase
 Submandibular and sublingual glands

• Seromucous secretion
 Minor salivary glands

• Scattered throughout oral cavity

• Mucous secretion rich in mucin glycoproteins o Salivary secretion
 1.5 litres per day; Hyperosmotic (osmolarity less than that of blood); pH
 Composition includes

• Mucin glycoproteins

• Lysozyme (anti-microbial, protecting from infection)

• a-amylase

• Proline-rich proteins (protect enamel/epithelial cells by neutralising tannings, lubrication)
 Functions

• Lubricate food, make swallowing easier (mucin glycoproteins, H2O)

• Clean & protect cavity of mouth (lysozyme, proline-rich proteins)

• Reduce starch to oligosaccharide molecules (a-amylase) o General structure of salivary glands
 Main collecting duct
 Interlobular duct (lobule= secretory unit)
 Intercalated ducts
 Acinar cell (zymogen granules)
 Duct epithelial cells Saliva o Composition determined by both Acinar and Duct-lining Epithelial cells
 Acinar cells

• Generate primary secretion

• Needed to wash out secretions into mouth (NaCl & H2O)

• Cl- & a-amylase moves through cells, Na & H20 moves between cells

• Leaky epithelia
 Duct-lining epithelial cells

****************************End Of Sample*****************************

Buy the full version of these notes or essay plans and more in our Gastrointestinal (GI) System Notes.