Upper Gastrointestinal Tract (Salivary glands (Function (Digestion (Water…
Upper Gastrointestinal Tract
Mouth and Pharynx
Usually arranged in exocrine acinar structure
Contractile cells to squeeze Acini
are situated between the secretory cells themselves and the basement membrane. They are innervated by the
Water for lubrication
Amylase for carb digestion
Glycoproteins and electrolyte (potassium).
Calcium and phosphate
Lay down protein coat for teeth protection.
Under the front of the tongue
Appear pale on stain.
Open to numerous small ducts to submandibular and oral cavity.
Mixture of mucus and serous.
If the mucous cells exceed the serous cells in an acinus, then the serous cells are pushed to the edge of the acinus and form crescentic serous demilunes
duct extends from the back of the mouth to its opening in the floor of the mouth, just
behind the incisors
Can form stones and calculi that blocks the duct. (very painful)
Largest salivary gland
Serous secretion that stain dark.
thick outer connective tissue capsule, which sends trabeculae into the gland, dividing it into lobules.
The secretory acini are tightly packed within these lobules.
Never form stones in ducts being watery
ducts run within the cheek, and open into the mouth
beside the upper molars.
Hydrochloric acid and intrinsic factor: Produced by oxyntic (parietal) cells and confined to the fundus and body
Enzymes: Produced by zymogenic chief (peptic) cells; pepsinogen is converted to pepsin after secretion by hydrochloric acid
Hormones: Produced by enteroendocrine cells, not very numerous and scattered throughout the stomach. Endocrine cells producing gastrin are confined to the pyloric antrum.
Glands Division in the fundus and body
Isthmus: has mucus cells and few parietal.
Base: contain Zymogenic cells (chief cells)
Also enter enteroendocrine cells at the base
Neck: has parietal and mucus cells that secretes HCl acid and intrinsic factor