The Digestive System Dr. Dalia - PowerPoint Presentation

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The Digestive System

Dr. Dalia

Abd

Alkader

Ph.D

Pharmacology

Word Roots Specific to the Digestive System

Root or Suffix

Refers to

cholecyst

/o

gallbladder

duoden

/o

duodenum

enter/o

small intestine

hepat

/o

liver

pancreat

/o

pancreas

phag/o

eating; swallowing

The Muscular Apparatus of the Digestive System

Digestion starts in the mouth and proceeds through the pharynx, esophagus, stomach, small intestine, and large intestine. The “apparatus” as a whole has several names: alimentary canal, digestive tract, and gastrointestinal (abbreviated GI) tract.

The Pharynx

The pharynx has “dual citizenship.” It belongs to both the respiratory and digestive systems because it is a passageway for both air and for food and drink. Liquid and chewed food enters the pharynx from the oral cavity, and muscular action sends it to the esophagus.

The Esophagus

The esophagus is a muscular tube connecting the pharynx with the stomach. It is lined by moist pink tissue called mucosa. The esophagus runs behind the trachea.

The Stomach

It has four main areas are the

fundus

,

cardia

, body, and

antrum

.

The functions of stomach are:

A

. Temporary storage place for the

food

B

. Secreting acid and enzymes to help

break down proteins, fats, and

carbohydrates.

The Small Intestine

Ninety percent of nutrient absorption

occurs in the small intestine, and the

other 10% occurs in the large

intestine.

The first 10 inches of the small

intestine is called the duodenum.

The segment coming right after the duodenum is the jejunum. The jejunum is the segment from which most nutrients are emptied into the bloodstream. The final segment of the small intestine is called the ileum.

The Large Intestine

(colon)

Besides absorbing 10% of nutrients, the

large intestine compacts waste material

for elimination.

colon can be subdivided into the

ascending colon, transverse colon,

descending colon, and sigmoid colon.

Other Organs of Digestion

The Salivary Glands

There are three separate pairs of salivary

glands, located in different parts of the oral

cavity.

They are called the

parotid

,

sublingual

, and

submandibular

salivary glands. Although

saliva is more than 99% water, it contains

essential enzymes that break down complex

carbohydrates. Saliva also contains

antibodies that kill bacteria.

The Pancreas

The pancreas acts as both an endocrine and an exocrine gland. The pancreas provides insulin directly to the bloodstream (endocrine function) and secretes a fluid containing enzymes into the small intestine (exocrine function). Both of these pancreatic secretions are essential to digestion.

The Liver

The liver keeps the body's metabolism balanced and promotes good health by releasing fat-soluble vitamins, such as A and D, when the body needs them.

The liver also produces bile, which helps in breaking down the lipids (fats).

The Gallbladder

It is a small pouch that locates just under the liver. The gallbladder stores bile produced by the liver and delivers it to the small intestine.

Common disorders and procedures associated with the digestive system

Term

Definition

cholecystectomy

excision of the gallbladder

cholecystitis

inflammation of the gallbladder

colitis

inflammation of the colon

enteritis

inflammation of the intestine

enterospasm

painful peristalsis

gastrectomy

excision of part of the stomach

gastritis

inflammation of the stomach

hepatitis

inflammation of the liver

pancreatitis

inflammation of the pancreas

enterogastritis

inflammation of the intestine and stomach

enterostenosis

narrowing within the intestinal tract

Common Abbreviations:Abbreviation     Meaning

DM diabetes mellitus

GB gallbladder

GERD

gastroesophageal

reflux

disorder

GI gastrointestinal

NGT

nasogastric

tube