Gastrointestinal Tract Physiology Quiz

The process of breaking down food into smaller molecules that can be absorbed by the body.

The movement of food through the digestive tract, from the mouth to the anus.

The release of enzymes, acids, and other substances into the digestive system to aid in digestion.

The process of taking nutrients and water from digested food into the bloodstream.

The main organs involved in digestion: the mouth, esophagus, stomach, small intestine, large intestine, and anus.

The glands that produce saliva, containing enzymes that begin the process of carbohydrate digestion.

The process of swallowing, which moves food from the mouth to the esophagus.

The three pairs of salivary glands: parotid, submandibular, and sublingual.

Peristaltic waves that begin in the pharynx and continue down the esophagus during swallowing.

Peristaltic waves triggered by food remaining in the esophagus after the primary wave.

The smooth muscle found in the lower two-thirds of the esophagus is regulated by the vagus nerve.

Specialized cells in gastric glands that secrete HCl, intrinsic factor, and gastroferrin.

The process of moving food through the digestive tract and mixing it with digestive juices.

HCl is a strong acid secreted by parietal cells in the stomach. It plays a key role in digestion by breaking down food.

A glycoprotein secreted by parietal cells that aids in the absorption of vitamin B12.

The stomach is the first digestive organ within the abdominal cavity. It's designed for churning, storing, and digesting food.

Lysozyme and immunoglobulins in saliva help prevent infections and control oral bacteria.

The pharynx is a passage for air, food, and drink, and plays a crucial role in swallowing.

The esophagus is a muscular tube that connects the pharynx to the stomach, moving food through the neck and chest.

The vagus nerve directly innervates the esophageal muscles, helping control food movement.

Peristalsis is the wave-like muscle contractions that propel food through the esophagus, independent of conscious control.

Hunger is the internal desire for food, while appetite dictates the type of food we crave.

Mastication, or chewing, involves breaking down food using teeth, aiding digestion, especially for fibrous foods like fruits and vegetables.

Swallowing is a complex process that ensures both breathing and food transport can occur safely and efficiently.

The first part of the small intestine, where food from the stomach mixes with bile, pancreatic juice, and enteric secretions.

Powerful enzymes from the pancreas that are activated in the duodenum, facilitating rapid and efficient digestion.

Special cells in the duodenum that secrete hormones like cholecystokinin and secretin in response to food.

Substances that help emulsify fats, making them easier to digest and absorb.

The process of absorbing small molecules like sugars, amino acids, and electrolytes into the enterocyte.

The pancreas lies transversely on the posterior abdominal wall, with its head near the duodenum and its tail extending towards the spleen.

The main pancreatic duct runs the length of the gland, while a smaller accessory duct drains the superior part of the head.

The pancreas produces digestive enzymes, and its secretion is stimulated by hormones like cholecystokinin.

The gallbladder stores and concentrates bile, a fluid produced by the liver that helps digest fats.

Bile salts aid in the absorption of fats (like fatty acids and cholesterol) by forming micelles that make them easier to be taken up by the intestinal wall.

Without bile salts, a significant amount of ingested fats (up to 40%) would be lost in feces, leading to nutrient deficiency and potential health issues.

The jejunum is the middle section of the small intestine, about 3.5 meters long, and is responsible for nutrient absorption.

The ileum is the final section of the small intestine, about 2.5 meters long, and also plays a crucial role in nutrient absorption.

The small intestine absorbs a large volume of fluids each day, including ingested fluids and secretions from various digestive organs.

Specialized structures like folds of Kerckring, villi, and microvilli greatly increase the surface area of the small intestine, maximizing nutrient absorption.

The small intestine absorbs significant amounts of various nutrients, including carbohydrates, fats, amino acids, ions, and water.

The large intestine has tighter junctions between epithelial cells compared to the small intestine, limiting back-diffusion of ions and facilitating sodium absorption.

The large intestine secretes bicarbonate ions to neutralize acidic byproducts of bacterial action, while simultaneously absorbing chloride ions in an exchange.

Absorption of sodium and chloride ions creates an osmotic gradient, drawing water into the large intestine alongside these electrolytes.

The large intestine can absorb a maximum of 5-8 liters of fluid and electrolytes daily. Excess intake leads to diarrhea.

Bacteria in the colon, particularly colon bacilli, aid in digesting cellulose, providing extra calories for the body.

Bacteria in the colon produce vitamin K, B12, thiamine, riboflavin, and gases like carbon dioxide, hydrogen, and methane.

Vitamin K, produced by bacteria in the colon, is crucial for blood coagulation, as dietary intake alone is often insufficient.

Feces are mostly water and contain dead bacteria, fat, inorganic matter, protein, undigested roughage, and dried constituents of digestive juices.