Gastrointestinal Function Flashcards
identify the location and briefly explain the general role in the GI system of each of the following locations:
esophagus, lower esophageal spinchter
The esophagus connects the oropharynx to the stomach, lying beneath the trachea. It’s function is to be a conduit for the passage of food from the pharynx to the stomach.
the lower esophageal sphincter is at the bottom of the esophagus and serves to allow the food to pass through into the stomach, d/t “receptive relaxation”, which allows for easy propulsion of the food into the stomach.
identify the location and briefly explain the general role in the GI system of each of the following: pylorus, small intestine
the pylorus, or pyloric region, consists of the pyloric canal and the pyloric sphincter. The pylorus functions to help pass food along the digestive canal into the small intestine.
the small intestine is in the middle GI tract, and it’s function is to connect the stomach to the jejunum and contain the opening for both the common bile duct and the main pancreatic duct (duodenum), finally, the two latter parts of the small intestine focus on digesting and absorbing food (jejunum and ileum)
identify the location and briefly explain the general role in the GI system of each of the following components: large intestine and colon
the large intestine comes right after the small intestine and it’s function is to absorb water and salts from the material that has not been digested as food, and get rid of any waste products left over.
the colon is the large intestine, and a little bit after the large intestine as well. It removes water and some nutrients and electrolytes from partially digested food. The remaining material, solid waste called stool, moves through the colon, is stored in the rectum, and leaves the body through the anus.
identify the location and briefly describe the role in the GI system that each component plays: appendix
the appendix is an organ which arises from the cecum, approximately 2.5 cm from the ileocecal valve. the appendix’s purpose is thought to be a storehouse for the good bacteria in our gut.
compare the actions of the enteric nervous system and autonomic nervous system as they relate to the motility of the GI tract.
the enteric nervous system is the nervous system contained within the gut, and it is responsible for either slowing down or speeding up digestion. it is a linear chain of neurons between circular and longitudinal smooth muscle.
the autonomic nervous system will interact with the enteric nervous system to slow down digestion speed and motility of the GI tract.
compare digestion and absorption of fats, carbohydrates, and proteins.
fats:
briefly state the role of the hormones gastrin, secretin, and cholecystokinin in mediating secretion of gastrointestinal juices.
gastrin stimulates the release of gastric acid in the stomach to help chemically break down food.
secretin is a regulating hormone found in the small intestine. the entry of acid chyme into the intestine stimulates the release of secretin. Secretin then works to inhibits gastrin secretion. Secretin is released in response to duodenal pH, if it’s imbalanced, secretin will be released.
cholecystokinin (CCK) is a hormone found in the small intestine as well. CCK is responsible for stimulating the contraction of the gallbladder, and secretion of the pancreatic enzymes. CCK also slows gastric emptying, inhibits food intake.
define in the gastric mucosa: parietal cells, chief cells
parietal cells are those cells in the gastric mucosa that are located in the proximal 80% of the stomach and the gastric pits. They secrete hydrochloric acid (HCL), and intrinsic factor, which help break down digested food and help absorb vitamin b12, respectively.
chief cells are cells at the base of glands distributed throughout the fundus and corpus of the stomach. Their function is to secrete pepsinogen (when exposed to the low pH of the gastric juices), which is rapidly converted to pepsin to ultimately break down proteins.
define in the gastric mucosa: mucus cells, mucus layer, and gastrin cells.
mucus cells are those cells which continually secrete mucus that functions as a mechanical barrier, antimicrobial shield, and lubrication for foods.
The mucus layer is the first point of contact between the gut microbiota and the host.
The G cell or gastrin cell, is a type of cell in the stomach and duodenum that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells
where is an upper GI bleed?
Mouth
Esophagus
Stomach
where is a middle GI bleed?
Duodenum (Small intestine)
Jejunum (Small Intestine)
Ileocecal Junction
where is a lower GI bleed?
Colon: Ascending, Transverse, Descending
Rectum
