The Digestive System

3 functions Digestion – breakdown of food into nutrients that can be absorbed in the form of molecules Absorption – passage of nutrients into the bloodstream to be carried to body tissues & cells Excretion – elimination of waste products

Gastrointestinal Tract Extends from mouth to anus The gastrointestinal tract consists of the following : Mouth Throat Oesophagus Stomach Duodenum Small bowel Colon Rectum Anus

Other organs of GIT Liver (hepatobiliary system) Gallbladder Pancreas These organs lie outside GIT but contribute to the Digestion process

DIGESTIVE SYSTEM STOMACH LARGE INTESTINE LIVER

Mouth Food is moistened and chewed (i.e. mastication) Contains teeth, tongue, Contains hard & soft palate (roof of mouth) Contains uvula which stops food entering the nasal cavity with swallowing

Mouth Cont’d Salivary glands supply saliva with digestive enzymes for food breakdown Tonsils – located in oropharynx & produce leucocytes

Oesophagus Is a tube connecting pharynx to stomach Moves food into stomach by peristalsis

Oesophagus word component Word Root Combining form Meaning Oesophag oesophag/o oesophagus

Stomach Hollow organ Lies below diaphragm in upper abdominal cavity, LUQ It is divided into three (3) sections i) the fundus ii) the body which is the middle section iii) the pylorus (the lower, small end).

Stomach cont’d Gastric juices break down the food into watery material to make absorption easier Pepsin (an enzyme) also breaks down food Has 2 sphincters 1. cardiac sphincter – prevents regurgitation into oesophagus 2. pyloric sphincter – controls passage of food into small intestine

Word Components Word Root Combining form Meaning gastr gastr/o stomach pylor pylor/o pylorus

Small Intestine Is 6 metres long Nutrients from broken down food is absorbed through the intestinal walls 3 sections 1. duodenum –connected to pylorus of stomach 2. jejunum – middle section 3. ileum- lower section and joins onto large intestine

Stoma -stomy Stoma means a surgical opening -stomy is also referred to an operation to form an opening between two parts e.g. stomach to abdomen Can be an opening from the intestine onto the outside of the body after surgical removal of part of intestine

-stomy Is joined onto combining forms to add meaning e.g. Jejun / o / stomy is creation of a new opening through the abdominal wall into the jejunum Ile /o / stomy is creation of a new opening through the abdominal wall into the ileum

-stomy It is also used with two combining forms for organs & means an opening between two body parts or organs that would normally be separated Gastr / o / enter / o /stomy is a new surgical opening between stomach and small intestine NB: when the 2 combining forms gastr/o and enter/o are joined the combining vowel is retained

Suffixes Gram – refers to a drawing or picture Graphy – refers to the technique of making a recording Graph – refers to the instrument that make the recording

Word components Word root Combining form Meaning gastr gastr/o stomach duoden duoden/o jejun jenun/o ile ileo /o

Large Intestine (i.e. large bowel) 1 metre long Water is absorbed through large intestine back into body waste becomes solid

Large Intestine cont’d 3 major sections Caecum hold appendix Colon – ascending colon transverse colon descending colon sigmoid colon rectum

Word components Word Root Combining Form Meaning caec caec/o a blind ended pouch appendic appendic/o appendage col col/o large bowel sigm sigmoid/o sigmoid colon rect rect/o rectum peritone peritone/o peritoneum, membrane covering abdominal organs

Liver Liver –manufactures & releases bile Lies in RUQ Word Root Combining Form Meaning Hepat hepat/o liver Chol chol/e bile

Gallbladder Lies inferior surface of liver stores bile & releases bile through common bile duct into duodenum Word Root Combining Form Meaning cyst cyst/o bladder,combined with chole it refers to gallbladder choledoch choledoch/o common bile duct lapar lapar/o soft part between ribs & hips refers to the abdomen

Pancreas Lies posterior to stomach Produces juices filled with enzymes to digest food Releases digestive juices into the duodenum Secretes insulin which is a hormone is released when blood sugar levels rise pg 42

Procedures Cholecystectomy Cholecystography Colonoscopy Enterectomy Hemicolectomy Laparoscopy Uvulopalatopharyngoplasty pg 44

Prefixes Prefix Meaning dys difficult dyspepsia difficulty with digestion hypo below hypoglossal below the tongue sublingual hyper above.or more than normal hyperemesis excessive vomiting

Suffixes Suffix Meaning pepsia digestion ostomy surgical opening colostomy surgical opening into colon otomy surgical incision gastrotomy surgical incision into the stomach pg 45

Diseases and disorders Adhesion – fibrous band Ascites – accumulation of fluid in abdominal cavity Cachexia – abnormally low weight Cirrhosis – scarring of an organ (liver) Divrticulum – abnormal pouch in wall of a tube (colon ) Cholelithiasis – stones in gallbladder pg 46