Gastroenterology Quiz

The branch of medicine that focuses on the digestive system, covering its diseases, diagnosis, and treatment.

The digestive system's primary role is to process food, extract valuable nutrients, and eliminate waste.

Mechanical digestion physically breaks down food into smaller pieces, while chemical digestion uses enzymes to break down large molecules into smaller ones.

A long, muscular tube running from mouth to anus, responsible for food passage and digestion.

The stages are ingestion (taking in food), digestion (breaking down food mechanically and chemically), absorption (taking in nutrients), compaction (absorbing water and forming feces), and defecation (eliminating waste).

Organs that assist in digestion but are not part of the digestive tract, including teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

The innermost layer, composed of epithelium for secretion and absorption, lamina propria for connective tissue support, and muscularis mucosa for muscle movement.

MALT (mucosa-associated lymphoid tissue) is abundant in lymphocytes and lymphatic nodules, providing immune protection against pathogens.

The rectum is the final part of the large intestine before the anal canal. It plays a key role in storing feces before defecation.

The anal canal is the final 3 cm of the large intestine. It's responsible for expelling waste from the body.

Two sphincters control the anal canal: the internal anal sphincter made of smooth muscle and the external anal sphincter made of skeletal muscle. They work together to regulate waste expulsion.

The stomach churns food, mixes it with gastric juice, and breaks it down physically and chemically. It also releases chyme into the duodenum for further digestion.

The small intestine has contractions that mix chyme, bring it in contact with the mucosa for absorption, and move waste towards the large intestine.

Segmentation is a type of small intestine contraction that involves ring-like constrictions that help mix chyme and expose it to the mucosa for digestion.

The lower half of the anal canal is covered with non-keratinized stratified squamous epithelium for abrasion resistance during defecation.

The large intestine lacks circular folds and villi, meaning it has a smaller surface area compared to the small intestine. This is because its primary role is water absorption, not nutrient absorption.

Longitudinal wrinkles that form in the stomach's mucosa and submucosa when the stomach is empty. These wrinkles allow the stomach to expand when filled with food.

Depressions in the gastric mucosa that contain 2-3 tubular glands that open into the bottom of each pit.

Mucus cells secrete mucus, a slimy substance that protects the stomach lining from the corrosive effects of stomach acid.

Parietal cells secrete hydrochloric acid (HCl), intrinsic factor, and ghrelin. HCl is essential for digestion, intrinsic factor helps absorb vitamin B12, and ghrelin is a hunger hormone.

Chief cells are the most numerous cells in the stomach and secrete gastric lipase and pepsinogen. Gastric lipase digests fats, and pepsinogen is converted to pepsin, an enzyme that breaks down proteins.

The pyloric sphincter regulates the passage of chyme (partially digested food) from the stomach into the duodenum, the first part of the small intestine.

The duodenum is the first part of the small intestine where most chemical digestion and nutrient absorption occurs. It receives stomach contents, pancreatic juice, and bile.

The small intestine has a large internal surface area for efficient absorption and digestion, achieved through circular folds, villi, and microvilli. These projections increase the surface area by factors of 2-3, 10, and 20, respectively.

The epiglottis is a small flap of cartilage that tips posteriorly during swallowing to prevent food from entering the airway (larynx).

The upper, middle, and lower pharyngeal constrictors are muscles that contract sequentially, propelling the bolus (food mass) down the pharynx and into the esophagus.

Peristalsis is a series of involuntary muscle contractions in the esophagus (and other digestive organs) that propel food forward.

The lower esophageal sphincter is a ring of muscle that relaxes to let food pass from the esophagus into the stomach and then closes to prevent stomach contents from refluxing back up.

The stomach has four regions: the cardiac region, the fundic region (fundus), the body (corpus), and the pyloric region.

Gastric juice is a mixture of water, hydrochloric acid (HCl), and enzymes produced by the stomach's gastric glands. It activates enzymes, breaks down food, and protects against pathogens.

Pepsinogen is an inactive enzyme secreted by chief cells in the stomach. It is activated by hydrochloric acid (HCl) to form pepsin.

Chyme is the soupy or pasty mixture of partially digested food that forms in the stomach.

The renal corpuscle is the initial filtering unit of a nephron, composed of the glomerulus and Bowman's capsule.

Bowman's capsule has two layers: the outer parietal layer, made of simple squamous epithelium, and the inner visceral layer, composed of podocytes that wrap around the glomerulus.

The filtration membrane has three layers: the fenestrated endothelium of glomerular capillaries, the basement membrane, and the filtration slits formed by podocyte pedicels.

Glomerular filtration is the process of filtering blood plasma into the capsular space of Bowman's capsule, forming filtrate, which is essentially blood plasma without blood cells and most proteins.

Blood enters the nephron through the afferent arteriole, flows through the glomerulus, exits through the efferent arteriole, and then continues to peritubular capillaries or vasa recta, depending on the location in the nephron, before finally draining into the renal vein.

A type of muscle contraction in the small intestine that mixes and churns chyme, but does not propel it forward. It helps expose chyme to digestive enzymes and absorption.

A wave of muscle contractions that occurs in the small intestine between meals, helping to clear any remaining food and prevent bacterial overgrowth.

A valve that separates the small intestine and the large intestine. It usually stays closed to prevent the backflow of contents from the large intestine into the small intestine.

The large intestine absorbs water and electrolytes, compacts the undigested food into feces, and eliminates waste from the body. It doesn't play a significant role in chemical digestion.

Powerful contractions that occur in the large intestine, helping to move feces toward the rectum for elimination. They are triggered by the gastrocolic and duodenocolic reflexes.

The kidneys filter waste products from the blood, regulate blood volume and pressure, maintain electrolyte balance, produce hormones like erythropoietin and renin, and contribute to acid-base balance.

From outside to inside, they are the renal fascia, perirenal fat capsule, and fibrous capsule. These layers provide protection and support for the kidneys.