GI 1 Flashcards
(26 cards)
What begins the mechanical breakdown of food in the oral cavity?
Mastication by the teeth initiates mechanical digestion.
What enzyme starts chemical digestion in the mouth?
Salivary amylase begins carbohydrate digestion.
What is the role of the pharynx in digestion?
It assists in swallowing (deglutition), moving food from the mouth to the esophagus.
What controls gastric motility and peristalsis?
Parasympathetic NS stimulates, while sympathetic NS inhibits gastric motility.
What does cholecystokinin (CCK) do?
CCK is released when chyme enters the duodenum, aiding digestion and slowing gastric emptying.
What are the three phases of gastric secretion?
Cephalic (sight/smell), Gastric (stomach stretch), and Intestinal (presence in intestines).
What activates hydrochloric acid (HCl) secretion in the stomach?
Gastrin → Histamine → H2 receptors → Proton pump activation → HCl secretion.
What is the role of pepsin in digestion?
It digests proteins and is activated from pepsinogen in acidic environments.
How does the stomach protect itself from acid?
Through a mucosal barrier managed by prostaglandins that stimulate mucus and bicarbonate.
What can damage the gastric mucosa?
NSAIDs, alcohol, H. pylori, ischemia, and bile reflux.
What are the three key intestinal reflexes?
Ileogastric, Intestinointestinal, and Gastroileal reflexes control food movement.
What triggers the urge to defecate?
Rectosphincteric reflex: Stretching rectum opens internal sphincter.
What causes dental caries?
Bacteria like Streptococcus mutans and Lactobacillus produce lactic acid that erodes enamel.
What is gingivitis?
Inflammation of gums due to plaque or trauma from brushing.
What is oral candidiasis and when is it seen?
A fungal infection by Candida albicans, common in immunocompromised or antibiotic users.
What can cause anorexia in a patient?
Hypothalamic dysfunction, pain, nausea, stress, or systemic illness.
What is the physiological control center for hunger?
The hypothalamus.
What is dysphagia and what causes it?
Difficulty swallowing caused by neurological or structural disorders.
What is GERD and what exacerbates it?
Reflux of gastric contents into esophagus; worsened by obesity, hiatal hernia, spicy food, etc.
What is a hiatal hernia?
A portion of the stomach pushes through the diaphragm into the thoracic cavity.
What differentiates gastritis from PUD?
Gastritis = inflammation of stomach lining. Peptic Ulcer Disease = mucosal breakdown leading to ulcers.
How do gastric ulcers differ from duodenal ulcers?
Gastric: Pain during eating. Duodenal: Pain 2–3 hours after meals, relieved by eating.
Compare Crohn’s disease and Ulcerative Colitis.
Crohn’s: Anywhere GI, skip lesions. UC: Colon only, continuous lesions.
What are diverticula and diverticulitis?
Diverticulosis: Presence of pouches. Diverticulitis: Inflammation of pouches.
