Introduction to GI Flashcards
What are the main components of the GI tract?
- Mouth
- Pharynx
- Oesophagus
- Stomach
- Small intestine
- Large intestine
- Anal canal
What are the accessory organs of the GI tract?
- Teeth
- Tongue
- Salivary glands
- Liver
- Gallbladder
- Pancreas
What is ingestion?
Taking food in
What is digestion?
Breaking food down into nutrients
What is absorption?
Pulling nutrients into the bloodstream
What is excretion?
Getting rid of waste
What is another word for chewing?
Mastication
What are the names of the salivary glands?
- Parotid
- Sublingual
- Submandibular
What is the name of the enzyme found in saliva that breaks down carbohydrates into smaller sugars?
Salivary amylase
What are the layers of the GI tract?
- Adventitia / serosa
- Muscularis externa
- Submucosa
- Mucosa
What are the areas of the stomach called?
- Fundus
- Body
- Cardia
- Pyloric antrum
- Pyloric sphincter
What do the gastric glands produce?
- Hydrochloric acid
- Pepsin
- Mucus
- Water
What are the 3 layers of the small intestine?
- Duodenum
- Jejunum
- Ileum
What is the length of the small intestine approximately?
10.5m
What does the chyme stimulate?
Enteroendocrine cells produce cholecystokinin
What does cholecystokinin do?
- Stimulates the gallbladder to produce bile
- Stimulates the acinar cells in the pancreas to produce digestive enzyes `
What enzymes are produced by acinar cells?
- Pancreatic lipase
- Pancreatic amylase
- Proteases (trypsin)
What does pancreatic lipase break down?
Triglycerides into fatty acids and glycerol
What does pancreatic amylase break down?
Carbohydrates into oligosaccharides
What do proteases (trypsin) break down?
Proteins into smaller peptides
What does secretin do?
- Produced by enteroendocrine cells
- Stimulates pancreatic duct cells to produce water and bicarbonate
Where is bicarbonate produced?
Glands in the submocosa of the duodenal wall and pancreatic duct
Where is fiber absorbed
Large intestine
What is the passageway between the small intestine and large intestine called?
Ileocecal sphincter
How long is the colon?
1.5m
What are the areas of the large intestine called?
- Appendix
- Cecum
- Ascending colon
- Transverse colon
- Descending colon
- Sigmoid colon
- Rectum
What do the gut microbome produce?
- B and K vitamins
- Gases (CO2, methane and sulphorous compounds)
What does bile do?
Emulsifies fat (into micelles)
Where is the myenteric plexus located (causes smoot muscle relaxation)?
Muscularis externa
Where is the submucous plexus (meissner’s plexus) located?
The submucosa
What is the function of the submucosa?
- Controls size of blood vessels
- Secretion of digestive juices
What are the layers of the mucosa?
- Epithelial layer
- Lamina propria
- Muscularis mucosa
What is the function of the epithelial layer of the mucosa?
Absorbs and secretes mucus and digestive enzymes
What is contained in the lamina propria?
Blood and lymph vessels
What is the function of the muscularis mucosa?
Smooth muscle (breaks down food)
