Digestive System Flashcards
What are the layers of the alimentary canal?
Mucosa, submucosa, muscularis (inner and outer), serosa
What is the movement of food within the GI tract called?
Peristalsis
What are the accessory organs within the digestive system?
The liver, gallbladder, pancreas.
The mucosa is made up of _______
Epithelial cells
The submucosa is made up of ________
Underlying tissue (containing glands, blood vessels, nerves)
The muscularis is made up of _______
An inner and outer muscle layer (a third internal layer within the stomach)
What 2 layers does the serosa form?
Visceral peritoneum and periental peritoneum (with serous fluid between)
What enzyme does saliva contain?
Salivary amylase
What does salivary amylase do in the mouth?
Assists with the initial digestion of carbohydrates - converts some to disaccharides.
The glands on the mucosa secrete ________
Mucus (lubricant..helps with the movement inside the GI tract) and digestive enzymes (breakdown products from lumen)
The mixture of food and saliva is called ______
Bolus
Name the 3 pairs of salivatory glands
Parotid glands, submandibular glands, sublingual glands
Name and describe the 3 stages of swallowing.
Oral stage - voluntary muscles (tongue and cheeks) push bolus to pharynx)
Pharyngeal stage - involuntary pharynx muscles propel bolus into oesophagus.
Oesophageal stage - bolus moves by peristalsis into the stomach.
What allows food into the stomach?
Lower oesophageal sphincter
_____ are small pores in the lining of the thick stomach mucous membrane.
Gastric Pits
What are the 3 types of secretory glands in the gastric glands and what do they secrete?
Mucous cells - mucus
Chief cells- pepsinogen (inactive digestive enzyme) Parietal cells - hydrochloric acid and intrinsic factor
What is the purpose of hydrochloric acid?
Activates pepsinogen, converting it to pepsin, allowing it to convert proteins into polypeptides.
_____ is the name of the liquid released from the stomach into the small intestine
Chyme
The pyloric canal leads to the ______________ which controls gastric emptying.
Pyloric sphincter
______ and ______ stimulate the secretion of gastric glands
acetylcholine and gastrin
Taste, smell, food entering stomach cause SYMPATHETIC/PARASYMPATHETIC stimulation by the _________, which releases acetylcholine.
parasympathetic , vagus nerve
What is the function of the hormone gastrin? (2)
Stimulates gastric glands and increases mitosis in the mucosa - replaces damaged cells to protect outer layers.
Chyme entering the small intestine causes _____ impulses to _______ gastric secretion.
Sympathetic, inhibit.
Chyme stimulates the intestinal wall to release _______, which …..
Cholecystokinin
decreases gastric motility ( stomach emptying, intestine filling).