Lab - Digestion: Mouth through Esophagus

  

Nonkeratinized stratified squamous epithelium lines the beginning and end of the digestive tract. It lines the lumen of the mouth, pharynx, and esophagus (at the beginning) and the anal canal (at the end).

   

 Taste buds are located on the dorsal surface of the tongue as well on the hard palate, soft palate, the epiglottis, pharynx, and larynx. The taste buds of the tongue occur within papillae present in the stratified squamous epithelium of the tongue.  At the center of each taste bud is a pore; tasty chemicals fall into the pore, stimulating the taste cells to start their sensory analysis. The taste cells are not just passive receptors of sweet, sour, salty, umami, and bitter, but actively modify taste stimuli through complex chemical and electrical signals.

 

Teeth

  

GIF of changes due to braces.  Links to an external site.

 

 

Major Salivary Glands

   

Salivary glands consist of acini (clusters) of serous cells and mucus cells. The acini can be serous, mucous, or a mixture of serous and mucous. A serous acinus secretes proteins in an isotonic watery fluid full of enzymes. A mucous acinus secretes secretes mucin (lubricant). Mucous acini stain more weakly than serous acini, because of the techniques used to produce the sections. Parotid glands have mainly serous acini. Submandibular glands have a mixture of mucous and serous acini. Sublingual glands have mainly mucous acini.

  Esophagus