Human Anatomy and Physiology - The Digestive System

A collection of question and answer flashcards based on key concepts from the lecture on the digestive system in Human Anatomy and Physiology.

What are the main functions of the digestive system?

Take in food, break it down into nutrient molecules, absorb molecules into the bloodstream, and rid the body of indigestible remains.

What is the alimentary canal?

A continuous muscular tube that runs from the mouth to the anus, involved in digesting food and absorbing nutrients.

What are the six essential activities in the processing of food?

Ingestion, propulsion, mechanical breakdown, digestion, absorption, and defecation.

What is peristalsis?

A major means of propulsion of food that involves alternating waves of contraction and relaxation of adjacent segments of the alimentary canal.

What is the role of segmentation in digestion?

To mix food and break it down mechanically, allowing some propulsion to occur.

What are the four basic layers of the digestive organs?

Mucosa, submucosa, muscularis externa, and serosa.

What are the main types of glandular cells found in gastric glands?

Mucous neck cells, parietal cells, chief cells, and enteroendocrine cells.

Describe the function of the liver in digestion.

The liver produces bile, which is a fat emulsifier essential for fat digestion.

What stimulates the release of bile from the gallbladder?

Cholecystokinin (CCK) and secretion of bile salts due to enterohepatic circulation.

How are carbohydrates digested and absorbed in the small intestine?

Carbohydrates are broken down into monosaccharides before being absorbed across the intestinal epithelium by cotransport with sodium.

What is the primary function of the large intestine?

To reclaim water and electrolytes, prepare feces for elimination, and store waste until defecation.

What is the role of the gastrointestinal reflexes in controlling digestive activity?

Intrinsic and extrinsic neural reflexes regulate digestive processes and activity in response to mechanical and chemical stimuli.

What are chylomicrons and their role in lipid absorption?

Chylomicrons are lipoprotein particles that transport absorbed lipids from the intestinal tract to the lymphatic system.

What condition is characterized by an inflammation of the peritoneum?

Peritonitis.

Define defecation reflex.

The reflex that forces feces toward the anus and involves spinal contractions and sphincter relaxations.

What is gastritis?

An inflammation of the stomach lining that can be caused by various factors and breach the mucosal barrier.

What is the structure of the small intestine designed to maximize?

Nutrient absorption, through modifications like circular folds, villi, and microvilli.

How does aging affect the digestive system?

Decreased GI tract activity, production of digestive juices, absorption efficiency, and increased frequency of GI disorders.