Digestive System Overview

These flashcards cover key concepts related to the structure and functions of the digestive system, including organ functions, digestive processes, and related anatomy.

What are the main functions of the digestive system?

Ingest food, digest food, absorb nutrients, excrete waste.

What are the primary structures of the digestive system?

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

What are the accessory structures of the digestive system?

Salivary glands, teeth, liver, gallbladder, pancreas.

What is digestion?

The process of breaking food down into smaller particles that can be absorbed.

What is mechanical digestion?

The physical breakdown of food, such as chewing and the mashing action of the muscular digestive tract.

What is chemical digestion?

The alteration of food by chemicals like saliva, stomach acids, and digestive enzymes.

What is absorption in the digestive system?

The process through which the end products of digestion move through the walls of the digestive tract into the blood.

What are the four layers of the digestive tract?

Mucosal layer, submucosal layer, muscle layers, serosa.

What is peristalsis?

Rhythmic smooth muscle contractions that move food through the digestive tract.

What is the enteric nervous system?

A network of neuron connections in the layers of the digestive tract, known as the 'gut brain'.

What relationship does the enteric nervous system have with the central nervous system?

There is a reciprocal relationship between the two systems.

What are the primary functions of salivary glands?

To produce saliva, a watery fluid containing mucus and salivary amylase.

What is the role of the pharynx in digestion?

It is common for food, liquid, and air and helps channel food bolus to the esophagus.

What happens to the soft palate during swallowing?

It temporarily closes off the opening to the nasopharynx.

What length is the esophagus?

Approximately 25 cm (10 inches) long.

What stimulates peristalsis in the esophagus?

The presence of food.

What are the two esophageal sphincters?

Upper esophageal sphincter (UES) and lower esophageal sphincter (LES).

What is the primary function of the stomach?

To mechanically digest food and chemically digest proteins.

What is chyme?

The mixture of food and gastric juices in the stomach.

What is the function of gastric juices?

To aid in the digestion of food by including enzymes, hydrochloric acid, and intrinsic factor.

What regulates the rate of food moving into the intestine?

The pyloric sphincter.

How long is the small intestine?

Approximately 6 meters (20 feet) long.

What are the three sections of the small intestine?

Duodenum, jejunum, ileum.

What is the primary site for chemical digestion and absorption?

Duodenum.

What does the pancreas secrete into the small intestine?

Bile and digestive enzymes.

What are the main functions of the large intestine?

Absorption of water and electrolytes, synthesis of vitamins, temporary storage of waste, and elimination of waste.

What is the total length of the large intestine?

Approximately 1.5 meters long.

What does the liver secrete?

Bile made from cholesterol.

What is the gallbladder's primary function?

To store bile.

What stimulates the release of cholecystokinin?

Presence of fat in the duodenum.

What does bile do?

Emulsifies fat.

What type of gland is the pancreas?

Both an endocrine and exocrine gland.

What does pancreatic juice help digest?

All food groups.

What is the gut microbiome responsible for?

Overall health, nutrient synthesis and metabolism, and protection against pathogens.

What are prebiotics?

Substances that feed good gut bacteria.

What are probiotics?

Live bacteria that are beneficial to the gut.

What is the role of intestinal bacteria in large intestine?

Synthesis of vitamins K and B.

What happens to undigested food contents in the small intestine?

They are moved into the large intestine for further processing.

What is the function of the rugae in the stomach?

To allow the stomach to expand and contract.

How does the ileum affect gut motility?

It slows motility when it detects fatty acids.

What is the size of the duodenum section in the small intestine?

About 10 inches long.

What does the term 'chyme' refer to?

The mixture of food and gastric juices waiting to be digested.

What kind of bacteria is primarily involved in synthesizing vitamins in the large intestine?

E. coli.

What enzyme in saliva initiates the digestion of carbohydrates?

Salivary amylase.

What anatomical feature prevents food from entering the nasal passages during swallowing?

The uvula.

How does the large intestine contribute to water balance in the body?

By absorbing water and electrolytes from digestive contents.

What does the mucosal layer of the digestive tract consist of?

It lines the inside of the digestive tract.

What provides the digestive system with structural support?

The serosa or peritoneal membranes.

What is the purpose of bicarbonate secreted by the pancreas?

To neutralize the acidic chyme from the stomach.

What digestive regulatory function does the pyloric sphincter serve?

It controls the release of chyme into the small intestine.