digestion Flashcards
(20 cards)
Issues with what cause reflux?
The sphincter between the oesophagus and the stomach.
What are accessory components of the digestive system?
Liver, pancreas, gall bladder, teeth, tongue, saliva
What are the different parts of the stomach?
The top is the fundus, the main section is the body, the pyloric sphincter at the bottom,
What are the 4 layers of the stomach?
The outer layer is the peritoneum.
The next layer is muscle, so the stomach can churn. There are 3 layers of muscle.
The next layer is the submucosa, where the blood vessels sit. Also where lymphatic vessels sit
The next layer is the mucosa.
What are the 3 different layers n the muscle of the stomach?
Longitudinal, circular and oblique. They are all smooth vessel
What is the structure and function of the mucosa layer of the stomach?
It has small projections and is folded for surface area. The pockets in the folds are known as gastric pits. Cells sit on the surface of the projection in order to secrete important chemicals in digestion.
What is the enteric nervous system?
The digestive system’s own nervous system.
What is the gastro-colic reflex?
food bolus enters stomach, sends a signal to large intestine telling it to empty. The stomach also starts to secrete. First hormone is gastrin, which activates cells on mucosa to start secreting. They start secreting hydrochloric acid, pepsinogen. Increases churning action, known as motility. Increase in the secretion of mucus, which protects the stomach lining from acid.
What does stomach acid do?
It helps dissolve, breakdown and liquidify food. Activates some enzymes such as pepsinogen. Turns it into pepsin.
Once the contents of the stomach becomes acidic enough, about ph 3, the release of Gastrin is inhibited.
What is mushy, liquidified food known as?
Chyme. This get released from the stomach to the small intestine.
What are the 3 parts of the small intestine and what do they do?
The duodenum, where the majority of digestion takes place.
The jejunum where absorption takes place.
The Ileum, responsible for the absorption of vitamins.
What is the cell structure of the small intestine?
Peritoneum remains the same as the stomach.
Muscle layer is different because no churning. Only 2 lays, longitudinal and circular.
Still have a submucosa which is the same
Mucosa is different shape form. Larger projections – villi. Gastric pits are deeper and known as cripts. Even more surface area. Villi have own projections. Known as brush border. Still lined with cells and mucus still secreted.
What happens when chyme enters the duedenum?
The release of secretin and cck is triggered.
What affect does cck have on the body?
CCK acts on the gall bladder. Gall bladder contains bile. CCK causes contraction, releasing bile, helping to digest fat. Bile salts emulsify and break down fat.
CCK also stimulates the pancreas to release digestive enzymes. Amylase, lipase, tripepsin
CCK also inhibits the stomach. This gives the small intestine onetime.
What affect does secretin have on the body?
Secretin acts on the pancreas. Causes it to release bicarbonate. It’s an alkali to neutralise acidity of the chyme.
Secretin also inhibits stomach, reducing mucus and motility.
What’s the function and process of the liver?
Responsible for detoxification
Produces the bile but cannot store much. Needs to be secreted into gallbladder, which is like a little storage pouch. Bile travels from live down hepatic duct, down cystic duct. When gallbladder contracts, toned up and out, then down common bile duct.
Reuses and recycles bill salts.
What is the structure and function of the large intestine?
Shorter and thicker.
First part is cecum, then ascending colon, then transverse colon, then descending colon, sigmoid colon, rectum and anus.
No digestive function. Everything should hone been broken down. Absorptive, especially water. Storage and drying.
Absorbs sodium and potassium.
Helps to absorb bacteria. Good bacteria help break down carbohydrates. Byproducts of carb breakdown are methane and sulphur.
Which is the main organ for sodium, potassium and water absorption?
The kidneys.
What does the rectum do?
Stores faeces
What enables the emptying of the rectum?
The anal sphincter, a muscular sphincter.
