ap midterm 1 Flashcards
What are the four main layers of the gastrointestinal tract (GIT)?
Mucosa, submucosa, muscularis externa, and serosa
What is the function of the pharynx in digestion?
The pharynx serves as a passageway for food and air and plays a role in swallowing (deglutition).
What are the three stages of deglutition (swallowing)?
The three stages are the oral (voluntary) stage, pharyngeal (involuntary) stage, and esophageal (involuntary) stage.
What is the enteric nervous system, and what is its role?
The enteric nervous system is a part of the autonomic nervous system that regulates digestive functions, including motility, secretion, and blood flow within the GI tract.
How many deciduous (baby) teeth do humans typically have?
20 deciduous teeth.
How many permanent teeth do humans typically have?
32 permanent teeth.
What are the papillae of the tongue, and what is their function?
Papillae are small projections on the tongue that contain taste buds and help with the movement of food.
What are the major openings of the salivary glands into the mouth?
Parotid gland (opens near the second upper molar), submandibular gland (opens under the tongue), and sublingual gland (opens through multiple small ducts under the tongue).
What is the structure of the esophagus?
The esophagus is a muscular tube with a mucosal layer, submucosal layer, muscularis externa, and adventitia. Its upper portion contains skeletal muscle, and the lower portion contains smooth muscle.
What are the main secretions of the stomach?
Hydrochloric acid (HCl), pepsinogen (converted to pepsin), mucus, intrinsic factor, and gastrin.
What is gastritis?
Gastritis is the inflammation of the stomach lining, often caused by infection (H. pylori), stress, or the use of NSAIDs.
What is peptic ulcer disease, and what causes it?
Peptic ulcer disease involves sores or ulcers in the stomach lining or the first part of the small intestine, often caused by H. pylori infection or long-term use of NSAIDs.
What are the two main divisions of the autonomic nervous system that innervate the stomach?
The parasympathetic division (via the vagus nerve) stimulates digestion, while the sympathetic division inhibits digestion.
What is the role of parietal cells in the stomach?
Parietal cells secrete hydrochloric acid (HCl) and intrinsic factor, which is essential for vitamin B12 absorption.
What does the vagus nerve do in relation to the stomach?
The vagus nerve stimulates the secretion of digestive enzymes and gastric acid, enhancing digestion.
