Chapter 5 & 6

Digestive System

Functions of the Digestive System

• Breakdown foods into a form usable by the rest of the body – chemical form

• Absorb broken down nutrients and get them into the circulatory system for transportation to cells

• Eliminate any waste products that cannot be absorbed into the blood stream

Digestive System Conveyor BeltOral Cavity

Esophagus

Stomach

Small Intestines

Large Intestines

• Exterior to your body• Peristalsis• Nutrients taken; wastes

excreted

Oral Cavity• Food fibers are broken

down by teeth, tongue and hard palate in mastication (chewing)

• Deglutition (swallowing)• Rugae – located on hard

palate to help grind up the food in preparation for digestion

• 32 Teeth– Incisors: front teeth– Molars: back teeth

• Mesial surface – toward midline of body

• Buccal surface – toward cheek• Labial surface – touch the lip• Distal surface – toward back or

throat• Incisal surface – part that

comes together when you bite down (incisors)

• Occlusal surface – part that comes together when you bite down (molars)

Oral Cavity Continued• Saliva – secreted into

food to start the process of breaking down starches. Secreted by the:– Parotid gland – just in

front of ear– Sublingual gland – under

the tongue– Submandibular gland –

area of the lower jaw

Back of Mouth

Soft Palate

Pharynx

Esophagus

Esophagus• Epiglottis – stops food

from entering the larynx• Transport system to

stomach

Stomach• Cardiac Sphincter/lower

esophageal sphincter – the “doorway” to the stomach• Sphincter fails =

heartburn

• Gastric juices: hydrochloric acid & pepsin – food + gastric juices =

chyme

Cardiac Sphincter

Stomach

Pyloric Sphincter

Duodenum (small intestine)

Small Intestines

Duodenum

Jejunum

Ileum

• Duodenum• Jejunum• Ileum

Duodenum• Finishes process of

digestion• Starts absorption

process• Pancreas and

gallbladder secrete digestive juices

• Nutrients further metabolized

Jejunum & Ileum• Absorption of nutrients• All three sections

(duodenum, jejunum & ileum) have villi which increase the absorption surface of intestines and quickly absorb nutrients

Large IntestinesCecum

Ascending Colon

Transverse Colon

Descending Colon

Sigmoid Colon

Rectum

• Water absorption– Constipation vs. diarrhea

TERMS TO KNOW

ETIOLOGY• The process of studying the

cause

IDIOPATHIC• Pertaining to unknown

disease

TERMS TO KNOW

ANOREXIA• Lack of appetite in an ill

patient

ASCITES• Accumulation of fluid in

abdomen• Characteristic of CHF

TERMS TO KNOW

BORBORYGMUS• Growling stomach• Movement of gas, fluid or

both in GI tract

DYSPHAGIA• Trouble swallowing• Often occurs after person

has a stroke

TERMS TO KNOW

CONSTIPATION• Fecal material stays in

intestines too long becoming hard and compressed from excessive removal of water from stool

DIARRHEA• Stool passes too quickly

through intestines resulting in no water loss from stool

TERMS TO KNOW

FLATUS• Gas expelled through anus

ERUCTATION• Gas expelled through

mouth

TERMS TO KNOW

HEMATOCHEZIA• Bright red blood on outside

of stool• Sign of bleeding on the

lower end of digestive tract• Sign of hemorrhoids

MELENA• Black tarry stools• Blood digested in stool – GI

hemorrhage has taken place in the beginning to middle of the digestive system; most likely stomach or duodenum

TERMS TO KNOW

NAUSEA• Upset stomach feeling

JAUNDICE• Yellow-orange color of skin

when high bilirubin is present in blood

• Icterus – color of the whites of the eyes

TERMS TO KNOW

STEATORRHEA• Fat in stool• May be indication of

pancreatic disease

HEMORRHOIDS• Varicose veins in the rectum• Caused by increased

pressure on rectum from constipation or pregnancy

TERMS TO KNOW

APHTHOUS STOMATITIS• Cancer sores• Inflammation of the mouth

with small ulcers

HERPETIC STOMATITIS• Blisters/cold sores• Infection of herpes virus

TERMS TO KNOW – Please review in book!

• Dental caries• Colonic polyposis• Colorectal cancer• Dysentery• Gastric Carcinoma• Ileus• Irritable bowel syndrome• Ulcerative colitis• Cirrhosis• Pancreatitis

TERMS TO KNOW

ORAL LEUKOPLAKIA• White plaques/patch on

mouth• Precancerous lesion

– Chewing tobacco

PERIODONTAL DISEASE• AKA pyorrhea• Bacteria cause inflammation

and degeneration of gums, teeth and surrounding tissue

TERMS TO KNOW

ACHALASIA• Lower esophagus/cardiac

sphincter does not relax enough to allow food into stomach

CROHN’S DISEASE• Autoimmune disease• Severe inflammation and

destruction of tissue in colon

• Diarrhea, cramping, fever• Chronic condition for which

there is no cure

TERMS TO KNOW

ANAL FISTULA• Abnormal passageway from

rectum to outside of body

ANAL FISSURE• Crack or slit in the mucous

membrane of the anus

TERMS TO KNOW

DIVERTICULA• Out pocketing of intestine• Irritation and inflammation

which can result in diverticulitis

ESOPHAGEAL VARICES• Associated with cirrhosis of

liver• Liver becomes fibrotic and

blood cannot pass through; blood backs up in hepatic portal vascular system into the vessels around esophagus; vessels become clotted and twisted

TERMS TO KNOW

GASTROESOPHAGEAL REFLUX DISEASE

• GERD or heartburn• Contents of stomach return

up into the esophagus

ULCER• Open sore anywhere along

digestive tract – Most common is gastric and

duodenal– Caused by Helicobacter pylori

Hernia• Hiatal hernia – stomach

through diaphragm• Ventral hernia – intestine

through muscle and peritoneum in front abdomen

• Incisional hernia – intestine through location of a previous incision

• Inguinal hernia – intestine through inguinal ring

• Hernias can be:– Reducible: can be pushed

back into position within the abdomen

– Incarcerated: cannot be reduced and is held in position by the abdominal muscles

– Strangulated: incarcerated with a piece of stool lodged in that section causing swelling and blood supply being cut off

TERMS TO KNOW

INTUSSUSCEPTION• Telescoping of intestines;

one piece inside the other• Serious , painful and occurs

often in children and young adults

VULVULUS• Twisting of intestines upon

themselves• More serious than

intussusceptions and occurs in newborns and small children

• Requires immediate surgery

TERMS TO KNOW

CHOLELITHIASIS• Gallstones in gallbladder

CHOLEDOCHOLITHIASIS• Gallstones in gallbladder

and duodenum

VIRAL HEPATITIS

• Hepatitis A: transmitted via oral/fecal route• Hepatitis B: transmitted through blood route• Hepatitis C: transmitted through blood route –

worst of all because there is no cure

TERMS TO KNOW• Laboratory tests in text• Clinical procedures in

text• Abbreviations

BE BRBPR EGDERCP GERD NG tube

NPO PEG tube PUD

SGOT SGPT TPN

ROOT OPERATIONSRoot Operation What

operation doesObjective of Procedure

Procedure Site Example

Inspection Involves exam only

Visual/manual exploration

Some/all of a body part

Diagnostic cystoscopy

Control Includes other repair

Stop/attempt to stop post-surgical bleed

Anatomical region

Post-prostatectomy bleeding

Excision Takes out some/all of a body part

Cutting out/off without replacement

Some of a body part

Breast lumpectomy

Release Involves cutting or separation only

Freeing a body part from constraint

Around a body part

Adhesiolysis

Restriction Alters the diameter/route of a tubular body part

Partially closing orifice/lumen

Tubular body part

Gastroesophageal fundoplication