Digestive System

The intake of food into the mouth.

ingestion

What is the function of saliva?

Lubricates food and begins chemical digestion.

What enzyme is found in saliva?

salivary amylase

What does salivary amylase digest?

Starch into smaller carbohydrates

What is the function of the esophagus?

Transport food from the mouth to the stomach.

How does food move through the esophagus?

by peristalsis

Does digestion occur in the esophagus?

no

What are the main functions of the stomach?

Storage, churning of food, and chemical digestion.

What is the pH of the stomach?

Very low (highly acidic)

What is gastric juice?

A mixture of HCl, pepsinogen, and mucus.

What is the function of hydrochloric acid (HCl)?

Denatures proteins and activates pepsin.

A protease that digests proteins.

pepsin

How does the stomach protect itself from digestion?

A thick mucus layer protects the stomach wall.

What is the basic gross structure of the stomach?

Muscular sac with folds called rugae.

Where is the liver located?

upper right abdomen

How is the liver structurally related to the GI system?

Connected via bile ducts to the small intestine.

What does the liver produce for digestion?

bile

What is the liver’s role in blood glucose regulation?

Stores glucose as glycogen and releases glucose when needed.

What is the liver’s role in detoxification?

Metabolizes drugs, alcohol, and toxins.

A digestive fluid that emulsifies fats.

-Breaks large fat droplets into smaller droplets to increase surface area.

bile

Where is bile produced?

liver

Where is bile stored?

gallbladder

What digestive enzymes does the pancreas produce?

Amylase, lipase, proteases (trypsin, chymotrypsin).

How do pancreatic enzymes reach the small intestine?

through the pancreatic duct

does the pancreas have endocrine functions?

yes, insulin and glucagon secretion.

what is the main function of the small intestine?

Absorption of nutrients and water.

What are the three anatomic subdivisions of the small intestine?

Duodenum, jejunum, ileum.

Where does most chemical digestion occur?

duodenum

Increases surface area for absorption.

villi

What do lacteals inside villi absorb?

fats

Does the small intestine produce enzymes?

yes

How is stomach acid neutralized in the small intestine?

By bicarbonate from the pancreas.

What is the main function of the large intestine?

absorption of water and electrolytes.

What is the role of bacterial flora?

Produce vitamins (K, B) and ferment undigested material.

What is the gross structure of the large intestine?

Cecum, colon, rectum.

What is the function of the rectum?

storage and elimination of feces.

Rhythmic muscular contractions that move food through the GI tract.

peristalsis

Is peristalsis voluntary or involuntary?

involuntary

What hormones regulate digestion?

Gastrin, secretin, cholecystokinin (CCK).

What does gastrin stimulate?

HCl secretion in the stomach.

What does secretin stimulate?

Bicarbonate release from pancreas.

What does CCK stimulate?

Pancreatic enzyme release and gallbladder contraction.

A network of neurons that independently controls digestion; part of the autonomic system

enteric nervous system

What processes does the digestive system regulate?

Peristalsis, secretion, and blood flow.

Mouth =

ingestion + amylase

Esophagus =

transport

Stomach =

acid + protein digestion

liver =

bile + detox + glucose regulation

Gallbladder =

bile storage

Pancreas =

digestive enzymes + insulin/glucagon

Small intestine =

digestion + absorption

Villi =

surface area

Large intestine =

water absorption

Rectum =

waste storage

Peristalsis =

movement

Gastrin, secretin, CCK =

hormone control

Enteric nervous system =

automatic digestion control