Maintenance Systems Unit 5 The Digestive System Maintenance Systems Unit 5

The Basic Functions of the Digestive System Ingestion-taking nutrients into the body, i.e., eating Digestion-the mechanical and chemical breakdown of food into a usable form Absorption-the movement of molecules through the mucosal lining of the stomach and small intestine, and into the blood Excretion-the removal of solid waste from the body

The Digestive Organs Mouth Pharynx Esophagus Stomach Small Intestines Large Intestines Rectum Anus

Mouth Ingestion- eating Mechanical digestion Chemical digestion Teeth Mastication-chewing Chemical digestion Salivary glands- secrete salivary amylase digestion of carbohydrates begins Mechanical +Chemical digestion Softens food and creates a bolus

Teeth (accessory organ) Four types of teeth Incisors- front 4 top and bottom Cuspids- also known as canines for their pointed shape Bicuspids- also known as premolars and have a flattened crown Molars- back teeth for crushing and grinding food “typical” tooth parts Crown/neck/root- from top to bottom Enamel/dentin/pulp- from outside in Gingiva- gums Peridontal ligament/cementum- hold teeth to jaw

Pharynx (throat) Deglutition- swallowing A passageway for food, liquids, and air

Esophagus Muscular tube located behind the trachea About 10 inches long Peristalsis- wave-like contractions Transports bolus from the pharynx to the stomach

Stomach J-shaped pouch located below the diaphragm Fundus Rugue Sphincter Mechanical digestion maceration (churning) Chemical digestion gastric juice secretion Hydrochloric acid- breaks down bolus into chyme Pepsin- breaks down protein

Small Intestines Mechanical digestion Chemical digestion Peristalsis continues Absorption of nutrients is highly active Chemical digestion Bile- made in the liver, stored in the gallbladder; emulsifies fat Trypsin- made in pancreas to break down protein Amylase- made in pancreas to break down carbohydrates Lipase- made in pancreas to break down fats Three divisions of the small intestines: Duodenum – first portion of the small intestine where the majority of chemical digestion occurs. Jejunum – middle portion of the small intestine where the majority of absorption of nutrients occurs. Ileum – final portion of where absorption occurs.

Large Intestines Also called the colon Mechanical digestion Cecum Ascending colon, transverse colon, descending colon, sigmoid colon Rectum Anus Mechanical digestion Haustral churning Absorption- water, vitamins, electrolytes, production of vitamin K; changes chyme to feces

Rectum The last portion of the large intestine which functions as a temporary storage of solid wastes before excretion

Anus The final portion of the rectum Mechanical digestion Defecation- excretion of feces through anal sphincter (anus)

Diseases and Disorders of the Digestive System

Colon Cancer Most of the cancers of the large intestine are believed to have developed from polyps (benign tumors). Cancer of the colon and rectum, also called colorectal cancer can invade and damage adjacent tissues and organs. Symptoms include fatigue, weakness, shortness of breath, change in bowel habits including diarrhea or constipation, red or dark blood in stool, weight loss, abdominal pain, cramps, or bloating. Surgery is the most common treatment for colon cancer.

Chron’s Disease Chron’s disease is an ongoing disorder that causes inflammation of the digestive tract. The disease can affect any area of the GI tract, from the mouth to the anus, but it most commonly affects the lower part of the small intestine, the ileum. The swelling extends deep into the lining of the affected organ. The swelling can cause pain and can make the intestines empty frequently, resulting in diarrhea. Chron’s disease may be caused by an abnormally functioning immune system. Treatment includes prescription medications, nutritional supplements, surgery, or a combination of these. There is no cure.

Celiac Disease Celiac disease is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food. People who have celiac disease cannot tolerate a protein called gluten, found in wheat, rye, and barley. When people with celiac disease eat foods or use products that contain gluten, their immune system responds by damaging the small intestine. Celiac disease is an autoimmune disease that is genetic. The most common symptoms include pain in the digestive system or other parts of the body. The only know treatment is a gluten-free diet.

Appendicitis Appendicitis, inflammation of the appendix, is the most common surgical disease. It results from the obstruction of the opening to the appendix by a mass, stricture or infection. Symptoms of appendicitis include generalized abdominal pain, pain localized in the lower right abdomen, nausea, vomiting, possibly fever, and an elevated white blood cell count. Treatment involves the removal of the appendix and antibiotics.

Inguinal Hernia Inguinal hernias occur when a part of the intestine protrudes through a weak point or tear in the abdominal wall. This protrusion creates a bulge which can be painful. Some inguinal hernias occur at birth when the abdominal lining does not close properly. Other inguinal hernias occur later in life when muscles weaken or deteriorate. The most common treatment is surgery.

Careers Dentist Dental Assistant Dental Hygienist Dietitian Central Service Technician

DENTIST Diagnose, prevent, and treat problems with teeth or mouth tissue. Remove decay, fill cavities, examine x-rays Extract teeth and make models and measurements for dentures to replace missing teeth. Administer anesthetics and write prescriptions for antibiotics and other medications 2-4 years of pre-req (Bachelors degree) + 4 years of dental school and 2 year internship, pass licensing boards 9 specialty areas to pursue after (orthodontics, surgery, periodontist…) 2-4 + years of school and post residency Salary: $95,000-160,000

DENTAL HYGIENTIST Remove soft and hard deposits from teeth Teach patients how to practice good oral hygiene Take and develop dental x-rays; and apply cavity-preventive agents such as fluorides and pit and fissure sealants Hygienists sometimes work chair-side with the dentist during treatment Associate degree, can go on and get Bachelors and Masters degree, licensure is required $45,000-70,000

DENTAL ASSISTANT Make patients as comfortable as possible in the dental chair, prepare them for treatment, and obtain their dental records. Hand instruments and materials to dentists and keep patients’ mouths dry and clear by using suction or other devices. Assistants also sterilize and disinfect instruments and equipment On the job training, can obtain dental assistant certificate through 1 year program at ATCs $22,000-35,000/year

DIETITIAN Plan food and nutrition programs and supervise the preparation and serving of meals Help to prevent and treat illnesses by promoting healthy eating habits and recommending dietary modifications Dietitians manage food service systems for institutions such as hospitals and schools Work in hospitals, private settings, universities, research labs, long term care facilities, private consultants Bachelors degree in Dietetics or Food and Nutrition- licensure required $40,000-60,000

CENTRAL SERVICES TECHNITICIAN Responsible for the procurement of surgical supplies and equipment Responsible for contaminating, cleaning, processing, assembling, sterilizing, storing and distributing the medical devices and supplies needed in patient care, especially during surgery On the job training is an option, but obtaining a certificate as a Central Services Technician preferred- 8 week program Work primarily in hospitals $25,000-35,000

Word Parts- roots Col/o- colon Cheil/o- lip Gastr/o- stomach Gingiv/o- gum Stomat/o- mouth Hepat/o- liver Cholecyst/o- gallbladder Proct/o- rectum

Word Parts/Abbreviations -ia – condition -itis –inflammation GI- Gastrointestinal IV- intravenous Tx- treatment Dx- diagnosis

Vocabulary Absorption- uptake through a membrane or tissue Bolus- semi-solid food lump Chyme- liquefied food mixed with enzymes Defecation- evacuation of fecal matter Deglutition- swallowing Digestion- process of breaking down food into a usable form Emulsification- breakdown of large lipid molecules into smaller ones

Vocabulary Excretion- evacuation of fecal matter Feces- undigested waste products Haustral churning- muscular contraction pushing matter into next pouch Ingestion- eating, taking in food Maceration- churning within the stomach to soak bolus in enzymes Mastication- chewing Peristalsis- wave-like motion