GI, Hepatobiliary, Pancreatic Flashcards
“G cells” within the stomach produce what hormone in response to ingestion of food, gastric distention, and high-protein foods?
Gastrin
Gastrin results in the production of
Hydrochloric acid (HCl)
To aid in liquefying food
What other factors stimulate gastric secretion and HCl release?
Increases in acetylcholine and histamine
What is the main driving force for gastric HCl acid production?
The hydrogen-potassium (H+/K+) ATPase pump
What type of medications can target and block the H+/K+ ATPase pump?
Proton pump inhibitors (PPI)
“I cells” produce what hormone in the small intestine in response to ingestion of high-fat meals and results in gall bladder contraction and pancreatic secretions?
Cholecystokinin (CCK)
“S cells” produce what hormone in the small intestine in response to increased levels of hydrochloric acid in the duodenum and results in release of bicarbonate and water to dilute and alkaline the duodenum as necessary?
Secretin
What hormone is produced in the small intestine and responsible for Gi motility?
Motilin
What promotes gastric emptying?
Gastric distention and Gastrin release
What inhibits gastric emptying?
Duodenum distension, duodenal irritation, increased acidity in the duodenum, or increases in cholecystokinin (CCK)
NSAIDs block production of
Prostaglandins
The epithelial cells within the gastric mucosal barrier contain a significant number of
Hydrophobic phospholipids that repel gastric acid
Protects stomach from autodigestion by gastric acid
Gastric epithelial cells are high in intracellular ________ that neutralizes acid
Bicarbonate
The effect of prostaglandin blockade is decreased ability of the body to withstand acidic stomach contents, resulting in
Gastritis and potentially GI ulcers
Small intestine consists of
Duodenum, jejunum, and ileum
The intestinal tract is influenced by both nervous systems
Parasympathetic and sympathetic
Enteric nervous system (ENS) consists of 2 types of plexus
Myenteric plexus (Auerbach’s plexus) Submucosal plexus (Meissner’s plexus)
Myenteric plexus responsible for
Propulsive intestinal movement
Submucosal plexus responsible for
Intestinal secretions and regulation of regional blood flow
Enteric neurons utilize numerous neurotransmitters
Dopamine
Serotonin
Acetylcholine
Substance P
Cholecystokinin
ATP
Somatostatin (vascoactive intestinal polypeptide)
Enkephalins
The enteric nervous system (ENS) continually communicates with
Central nervous system (CNS)
Hormones that enhance intestinal peristalsis include
Motilin, acetylcholine, serotonin, insulin, cholecystokinin, and Gastrin
Hormones that inhibit intestinal peristalsis
Norepinephrine, epinephrine, glucagon, and secretin
Blood flow to the GI tract originates from the
Aorta via the celiac, cranial mesenteric, and caudal mesenteric arteries
The contributions of the pancreas and hepatobiliary system mediate the breakdown of ____, ____, and ____ in the ________.
Fats, proteins, and carbohydrates
Duodenum
The hepatobiliary system is made up of
Gall bladder
6 Liver lobes : left medial and lateral, quadrate, right medial and lateral, and caudate
What causes the release of cholecystokinin (CCK)
Eating»CCK release»causes gall bladder contraction
The hepatobiliary system contributes ____ which contains ____ ____ that emulsify fat and aid in the digestion of fat-soluble vitamins (vit k)
Bile
Bile salts
Bile flows from the gall bladder to the
Cystic duct»common bile duct»duodenum
Pancreas is a small gland that lies adjacent to the _____ and possesses both _____ and _____ tissue.
Duodenum
Exocrine and endocrine tissue
The exocrine function of the pancreas promotes release of enzymes, including
Trypsin and Chymotrypsin - break down protein
Amylase - break down carbs
Lipase - break down fat
Functional units of the pancreas
Islets of Langerhans
Islets of Langerhans give the pancreas ______ functions
Endocrine
Endocrine functions of the pancreas include
Release of hormones that help maintain normoglycemia (insulin)
Which hormones act as stimuli for exocrine pancreatic function
Acetylcholine
Cholecystokinin
Secretin
The pancreas is also crucial in the secretion of _______ to help neutralize gastric hydrochloric acid
Bicarbonate
Where does nutrient absorption largely occur?
Small intestine
Where does fluid absorption mostly take place?
Via?
Large intestine
Via osmosis
Where is the vomiting center located?
The medulla of the brain
What is CRTZ?
Chemoreceptor trigger zone
The CRTZ is a common initiator of the vomiting reflex following stimulation by
Drugs and toxins
Uremia, ketonemia, endotoxins, and bilirubin
What receptors are present in the vomiting center?
Serotonin
Alpha-2 adrenergic
What CRTZ receptors are involved in the stimulation of vomiting and can be targeted with drug therapy to prevent vomiting?
Dopamine
Serotonin (5-HT3)
Histamine (H1)
Muscarine (M1)
Neurokinin (NK1)
Enkephalin
Alpha 2 adrenergic
What percent of GDV’s reoccur without a gastropexy?
80%
