Human Anatomy and Physiology I - Chapter 25: Digestive System

Flashcards summarizing key concepts from the lecture notes on the digestive system, covering anatomy, physiology, and processes involved in digestion.

What is gastroenterology?

The study of the digestive tract and the diagnosis and treatment of its disorders.

What are the five stages of digestion?

Ingestion, digestion, absorption, compaction, defecation.

Define mechanical digestion.

The physical breakdown of food into smaller particles, involving actions of the teeth and stomach.

What is chemical digestion?

A series of hydrolysis reactions that breaks dietary macromolecules into their monomers, facilitated by digestive enzymes.

Name the two subdivisions of the digestive system.

Digestive tract and accessory organs.

What is the length of the digestive tract?

Approximately 30 feet.

List the main organs of the digestive tract.

Mouth, pharynx, esophagus, stomach, small intestine, large intestine.

What are the layers of the digestive tract wall?

Mucosa, submucosa, muscularis externa, serosa.

What is the function of the enteric nervous system?

It controls gastrointestinal motility and glandular secretions.

Describe the relationship of mesenteries to the digestive system.

Connective tissue sheets that suspend the stomach and intestines from the abdominal wall.

What is the cephalic phase of gastric function?

It involves the response of the stomach to sensory stimuli like sight, smell, and taste of food.

What is the primary function of the liver regarding digestion?

Secretion of bile which contributes to digestion.

What is the function of the gallbladder?

To store and concentrate bile by absorbing water and electrolytes.

What types of enzymes are secreted by the pancreas?

Digestive enzymes, including amylase, lipase, proteases, and nucleases.

Where does most digestion and absorption occur?

In the small intestine.

What are villi and microvilli?

Folds in the small intestine that increase surface area for absorption.

What is the primary role of the large intestine?

To absorb water and salts from indigestible residue and eliminate feces.

What is a common cause of diarrhea?

Insufficient absorption of water in the large intestine.

What stimulates the defecation reflex?

Stretching of the rectum.

What are the two types of secretions from the salivary glands?

Intrinsic (continuous) and extrinsic (stimulated by food presence).

What are the roles of pepsin in digestion?

It digests proteins in the stomach by breaking peptide bonds.

What is the main function of bile salts?

To emulsify fats to aid in their digestion and absorption.

What is the role of the pancreatic duct?

It transports pancreatic juice to the duodenum for digestion.

Define peristalsis.

Involuntary wave-like muscle contractions that move food through the digestive tract.

What is the role of intestinal microbiota?

They help digest cellulose, pectin, and synthesize vitamins B and K.