The Digestive System s1

THE DIGESTIVE SYSTEM

The gastrointestinal tract (GIT) is the digestive system, sometimes called the alimentary canal. The organs that make up the digestive system function to take in, or ingest food, breakdown the food so nutrients can be absorbed into the body, and expel the leftover waste. The digestive organs include the mouth, oesophagus, stomach and intestines. Accessory organs, including the liver, gallbladder and pancreas, secrete chemicals to help breakdown food.

Mouth The mouth, or oral cavity, and is where food is chewed (or masticated) and moistened. The mouth contains the tongue, the teeth, the hard and soft palate and the uvula, a u-shaped process that hangs at the back of the mouth and swings upward when swallowing to stop food from entering the nasal cavity. Word root Combining form Meaning Fasc Fasci/o face Ganth Ganth/o, gnathic jaw Odont Odont/o tooth Phas, phasia speech Stomat Stomat/o mouth Or Or/o mouth Chiel Chiel/o lip Gingiv Gingiv/o gums Glos Gloss/o tongue Lingu Lingu/o tongue Palat Palat/o palate Sial Sial/o saliva

Oesophagus The oesophagus is the tube connecting the pharynx to the stomach. Food moves along it in a wavelike motion called peristalsis. Peristalsis continues through the stomach and the intestines break down food into smaller and smaller pieces.

Word Root Combining Form Meaning Oesophag Oesophag/o Oesophagus or gullet

Stomach The stomach is a hollow organ that lies under the diaphragm. Gastric acids in the stomach break down food into a watery material that can be absorbed by the small intestine. The stomach looks like a bag with two sphincters - ringlike muscular structures – at either end. The cardiac sphincter, nearest to the

Digestive System 2010 heart, stops food from regurgitating into the oesophagus. The pyloric sphincter controls the passage of food flowing into the small intestine. Word Root Combining Form Meaning Gastr Gastr/o Stomach Pylor Pylor/o Pylorus

-stomy means mouth or opening. It is also used to refer to an operation to form an opening between two parts. A stoma can be temporary or permanent.

gram refers to a tracing. Usually refers to an x-ray, paper recording or to a trace on a screen

graphy refers to the technique or process of making a recording

graph instrument that carries out the recording When the two roots gastr/o and enter/o are joined the combining vowel is retained.

Small intestine The small intestine is a coiled tube approximately 6 metres in length. Nutrients from the food broken down in the stomach are absorbed into the body through the walls of the small intestine. The small intestine has three major sections:

the duodenum - which connects to the pyloric end of the stomach

the jejunum - middle section

the ileum - the end section that connects to the large intestine

Word Root Combining Form Meaning Enter Enter/o Intestine Duoden Duoden/o First 30cm of the small intestine Jejun Jejun/o Refers to the jejunum Ile Ile/o Lower three fifths of the small intestine Large intestine The large intestine, or large bowel, is much shorter than the small intestine, being only 1.5 metres in length. In the large bowel the waste material from the digested food in carried. As it moves through the large bowel, water is absorbed back into the body and the waste material becomes solid.

Digestive System 2010 The large intestine has three major sections:

1 the caecum - holding the appendix

2. the colon - which has four parts,

 the ascending (upward) colon,  the transverse (across) colon,  the descending (downward) colon, and  the sigmoid colon.

3 the rectum - where the waste is held before being expelled through the anus

Word Root Combining Meaning Form Caec Caec/o A blindly ending pouch Appendic Appendic/o Appendage Col Col/o, colon/o Large bowel extending from the caecum to rectum Sigm Sigmoid/o Sigmoid colon Rect Rect/o Last part of large intestine Proct Proct/o Used to mean rectum or anus Peritone Peritone/o Peritoneum, membrane that covers abdominal organs

Liver The liver is located in the RUQ of the abdomen, partially protected by the rib cage. It is the largest gland in the body. It secretes an enzyme called bile. Bile breaks down fatty material so it can be absorbed into the body.

Word Root Combining Form Meaning Hepat Hepat/o Liver Chol Chol/e Bile

The Gallbladder The bile made by the liver is stored in a small sac, or bladder, on the under side of the liver. When the bile is needed for digestion, the gallbladder releases it into the duodenum through a tube called the common bile duct.

Word Root Combining Form Meaning Cyst Cyst/o Bladder, combined with chole it refers to the gall bladder Choledoch Choledoch/o Common bile duct Lapar Lapar/o Soft part between the ribs and hips

Digestive System 2010 Pancreas The pancreas is a gland that sits posterior to the stomach. Among its many functions, the pancrease produces and secretes insulin. Insulin is a hormone that is released when blood glucose levels become raised.

Word Root Combining Form Meaning Pancreat Pancreat/o Pancreas

ACTIVITY 1

Look at the diagram of the digestive system and answer the following questions:

1. Is the stomach inferior or superior to the oesophagus?

2. If the mouth is the beginning of the digestive system, is the oesophagus distal or proximal to the pharynx?

3. How does food move down the oesophagus and through the intestine?

4. Which gland secretes insulin?

5. Where is bile stored?

6. Put the following organs in order from the beginning (mouth) to the end (anus) of the digestive system: jejunum, duodenum, oesophagus, uvula, caecum, stomach, colon, pylorus

Mouth ______Anus

Digestive System 2010 ACTIVITY 2

Build words which mean

To be able to speak two languages Inflammation of the oesophagus Instrument to view the stomach Surgical opening into the intestine Study of the stomach and intestine Removal of the jejunum Surgical opening into the ileum Inflammation of the appendix Disease of the colon Instrument to view the rectum Pain in the anus Enlargement of the liver Xray of the bile ducts Process of viewing the abdomen

Related prefixes Meaning dys difficult dyspepsia difficulty with digestion hypo below hypoglossal below the tongue hyper above, excessive or more than hyperemesis normal excessive vomiting

Related suffixes Meaning -pepsia digestion -ostomy mouth or opening or a new surgical -otomy opening incision

Medical term Meaning buccal pertaining to the cheek emesis or emetic vomit or vomiting enema introduction of fluid into the rectum

Digestive System 2010 fistula abnormal opening between two organs stom, stoma, or ostomy mouth or opening anastomosis joining of one organ to another retrograde going backwards Diseases and disorders of the digestive system

Disease/disorder Definition Adhesion A fibrous band or structure that abnormally holds two parts together Anorexia Lack or loss of appetite Ascites The accumulation of fluid in the abdominal cavity Cholecystitis Inflammation of the gallbladder Cholelithiasis Stones in the gall bladder Cirrhosis Scarring of an organ particularly the liver Colic Acute abdominal pain Diverticulitis Inflammation of a diverticulum particularly in the colon Diverticulum An abnormal pouch or ulcer in the wall of a tube particularly in the colon Dysphagia Difficulty in swallowing or talking Enteritis Inflammation of the small intestine Hernia Part of an organ pushing through a membrane or cavity wall Hepatomegaly Enlargement of the liver Oesophagitis Inflammation of the oesophagus Gastritis Inflammation of the stomach Haemoptysis Vomiting of blood Hepatitis Inflammation of the liver Nausea The sensation of sickness Ulcer A breakdown in mucous membrane Duodenal ulcer An ulcer in the duodenum Gastric ulcer A stomach ulcer Peptic ulcer An ulcer in either the stomach or duodenum Spasm Cramp Diarrhoea Frequent bowel action Malaena Black faeces Pruritis ani Itching around anus Flatus Gas in or from colon Occult blood Hidden blood, often in faeces Anorexia Loss of appetite Bulimia Excessive appetite Dyspepsia Difficulty with digestion Eructation Belching Polyphagia Excessive food intake Regurgitation Backflow of gastric contents into mouth ACTIVITY 3

Read the following paragraph and rewrite it using lay terms

Digestive System 2010 A 33 year old female presented with acute abdominal pain and a seven-day history of anorexia, nausea and vomiting. On examination, there was moderate tenderness in the RLQ, no hepatomegaly, and no signs of gastroenteritis. The patient was admitted to hospital and an appendectomy was performed. Histopathology of the appendix showed slight inflammation. The patient made a rapid recovery and was discharged yesterday.

______

Instruments to view various parts of the digestive system

Gastroscope Gastroenteroscope Sigmoidoscope Colonoscope Proctoscope Laparoscope

Digestive System 2010