D2 Digestion Flashcards
Define exocrine glands
Secrete substances via a duct onto an epithelial surface (surface of the body/ lumen of the digestive tract)
Give 4 digestive examples of exocrine glands
Salivary glands
Gastric glands
Pancreatic glands
Intestinal glands
Describe the structure of an exocrine gland
A duct lined with duct cells that ends in a round complex of secretory cells with high concentrations of vesicles, rough ER and mitochondira
Which two mechanisms can trigger the secretion of gastric juices?
Nervous and hormonal
What occurs at the sight and smell of food?
Gastric juices triggered
What occurs when distension happens?
Distention - stretching of the stomach
Causes sustained gastric stimulation
What hormone triggers the release of stomach acids secreted by the gastric pits?
Gastrin
What happens if stomach pH becomes very low?
Gastrin is inhibited by gut hormones (secretin and somatosatin)
Which part of the small intestine secretes digestive enzymes as food passes through?
Duodenum
What is the function of secretin and cholectoskinin?
Stimulates pancreas and liver to release digestive juice
What is in pancreatic secretion to neutralise stomach pH?
Bicarbonate ions
Treatment with what can increase stomach pH?
Proton pump inhibitors (PPI)
What is roughage?
Indigestible portions of food (e.g.: cellulose/lignin)
What is the advantage of roughage in the diet?
Provides bulk in the intestines and absorbs water to keep bowel movements soft
Reduces constipation
Lowers blood cholesterol and regulates sugar
How does H pylori cause stomach ulcers?
H pylori anchors under the epithelial lining of the stomach, damaging and depleting the mucus lining which will expose the stomach cells to the gastric acid which will slowly damage them
