Digestive System-1 Flashcards
(20 cards)
What are the 6 main functions of the digestive system
- Take in food, 2. break food into molecules, 3. absorb molecules into the bloodstream, 4. rid body of indigestible remains, 5. produce nutrients, 6. produce neurotransmitters
What is the purpose of the alimentary canal? what are the associated organs?
the purpose is to digest and absorb food through the mucosal lining into the blood.
the associated organs are the mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
what is the purpose of the accessory digestive organs? what are the associated organs?
the purpose is mechanical and chemical digestion of food
the associated organs are the teeth, the tongue, the gallbladder, and the digestive glands(saliva, liver, pancreas)
what are the 6 major digestive processes?
ingestion, mechanical breakdown, propulsion, digestion, absorption, compaction/digestion
What is the difference between peristalsis & segmentation?
Peristalsis involves adjacent segments of alimentary tract organs whereas segmentation involves nonadjacent segments of alimentary tract organs.
Peristalsis only has forward movement whereas segmentation has forward and backward movement.
What is the difference between visceral and parietal peritoneum?
Visceral peritoneum is the membrane that lines the outside of digestive organs
Parietal peritoneum is the membrane that lines the entire body wall
What is the peritoneal cavity? what does it do?
A fluid filled space between two peritoneum’s.
It lubricates mobile organs.
What is a mesentery? what is it’s purpose?
A double layer of peritoneum fused together
It provides support for the organs(holds them in place), provides support for the vessels and nerves that supply the organs, and it stores fat
What is the difference between intraperitoneal and retroperitoneal rogans?
Intraperitoneal organs are located within the peritoneum
Retroperitoneal organs are located outside the peritoneum
What are 4 defining characteristics of the alimentary canal?
it extends from the mouth to the anus
most of the length is from the small intestine
the wall consists of 4 tissue layers
food travelling down the canal is broken down chemically from juices that are secreted by the digestive organs
what are the 4 basic tissue layers of all digestive organs?
Mucosa, Submucosa, Muscularis externa, Serosa
what are the 3 functions of the mucosa?
Secretion of mucus, digestive enzymes, hormones
Absorption of the end products of digestion
Protection from infectious disease
What are the 3 sublayers of mucosa? what is the main function of each?
Epithelium-secrete enzymes and hormones
Lamina Propria-absorption/protection
Muscularis mucosae-movement
What are 2 distinguishing features of the submucosa?
Allows stomach to regain shape after a big meal
Has a submucosal nerve plexus
What are 2 distinguishing features of the muscularis externa?
Where segmentation/peristalsis occurs
Has a myenteric nerve plexus
What are the 4 major arteries that give blood supply to the digestive system?
Where do they send blood to?
Hepatic artery-sends blood to the liver
Celiac artery-sends blood to the stomach and spleen
Superior & Inferior mesenteric artery-sends blood to the small & large intestine
What is the unique name for the nervous system of the digestive tract? What is it’s main function?
Enteric nervous system or “gut brain”
It controls motility
What is the main function of the submucosal and myenteric nerve plexus?
Submucosal nerve plexus regulates the glands and smooth muscle in the mucosa
Myenteric nerve plexus controls GI tract motility
What is the difference between short and long reflexes in the gut brain?
Short reflexes respond to stimuli inside the GI tract and control peristalsis/segmentation
Long reflexes respond to stimuli both inside and outside the GI tract and interact the CNS(ex. smelling food makes you hungry)
What are the 3 key concepts that regulate digestive activity?
- Digestive activity is provoked by mechanical and chemical stimuli(ex. stretch, blood pH)
- The 2 effectors of digestive activity are the smooth muscles and the digestive glands(muscles move lumen contents, glands release digestive juices)
The 2 controllers of digestive activity are the nervous system and hormones(short and long reflexes of nervous system, ghrelin and leptin hormones of digestive system)
