Digestive system Flashcards
What are the functions of the digestive system?
Prepares food for cellular consumption to provide energy and build new tissue.
What structures are involved in the digestive system?
Digestive tract and accessory organs (salivary glands, liver and pancreas)
What is the peritoneum?
A double layered serous membrane that covers the abdominal and pelvic cavities
What does the parietal peritoneum line?
The body wall
What does the visceral peritoneum do?
Covers the organs
What are the 4 basic layers of the gastrointestinal tract?
Mucosa, submucosa, muscularis externa and serosa/adventia
Blood from the stomach, pancreas, small and large intestine drains to the liver via…
The hepatic portal system
In the digestive system what part of the nervous system controls the short reflexes responsible for local peristalsis and glandular secretions?
Enteric nervous system
Where are the most postganglionic neurones located?
Enteric nervous system
What are the 3 main hormones involved in digestion?
Gastrin, secretin and cholecystokinin (CCK)
Churning in digestion breaks down the bolus. Where does churning occur?
In the stomach and the large intestine
What is peristalsis?
Waves of muscular contractions that move the bolus
Proteins are broken down by protease into…
Amino acids
Salivary amylase…
Initiates carbohydrate digestion
Where are parietal cells found and what do they produce?
Found in the stomach. They secrete hydrochloric acid and intrinsic factor
Where are chief cells found and what do they secrete?
Found in the stomach. They secrete pepsinogen
Enteroendocrine cells in the stomach secrete…
Gastrin
What activates the conversion of pepsinogen to pepsin?
HCl
What is the role of gastrin?
Stimulates the secretion of pepsinogen and HCl and stimulates contractions of gastric wall.
What is the role of intrinsic factors?
Aids in the absorption of vitamin B12
The pancreatic duct opens into the…
Duodenum at the sphincter of oddi
Where are acini cells found?
The pancreas
What enzymes do acini cells secrete?
Propeptidases, amylase, lipase, ribonuclease and deoxyribonuclease
Duct cells in the pancreas secrete…
Water and sodium bicarbonate
Alpha cells in the pancreas secrete…
Glucagon
Beta cells in the pancreas secrete…
Insulin
What is the function of the liver relative digestion?
Bile production
Role of the gall bladder
Stores and concentrates bile
During chemical digestion presence of fat and protein leads to the secretion of which hormones?
CCK and secretin
What effect does CCK have on the gall bladder?
Causes it to release bile
What effect does CCK have on the sphincter of oddi?
It causes it to relax
What effect does CCK have on the stomach?
It decreases gastric motility and secretion
CCK acts on which cells in the pancreas?
Acini cells
What effect does secretin have on the liver?
Causes it to release bile
What effect does secretin have on the stomach?
It decreases gastric motility and secretion
Secretin acts on which cells in the pancreas?
Pancreatic duct cells to release water and sodium bicarbonate
Which enzyme causes the conversion of trypsinogen to trypsin?
Enterokinase
Maltase converts maltose into…
Glucose and glucose
Lactase converts lactose into …
Glucose and galactose
Sucrose converts sucrose into…
Glucose and fructose
What do goblet cells produce?
Mucus
Bacterial flora in the digestive system synthesis which 2 vitamins?
B and K
