Digestive System HOSA medterm

Structure

primarily consits of the gastrointestinal (GI) tract

Upper GI tract

mouth, pharynx, esophagus, and stomach

Lower GI Tract (bowels)

small and large intestines, rectum, and anus

Accessory Organs

liver, gallbladder, and pancreas

Lips (labia)

surrounds opening to the oral cavity

Palate

forms the roof of the mouth

Hard Palate

anterior portion of the palate, covered with speialized mucous membrane

Soft Palate

flexible posterior portion of the palate

Uvula

hangs from the free edge of the soft palate

Tongue

very strong, flexible, and muscular

• posterior portion is attached; anterior portion moves freely and is flexible

Dorsum

upper surface covered in papillae

Papillae

small bumps containing taste buds

Sublingual Surface

lies under the tongue and covered with delicate vascular tissues

Lingual Frenum

band of tissue that attaches the tongue to the floor of the mouth

Periodontium

describes structures that surround, support, and are attached to the teeth

Gingiva (masticatory mucosa; gums)

specialized mucous membrane that covers the bone of the dental arches and surrounds the neck of the teeth

Dental Arches

bony structures of the oral cavity

Maxillary Arch

upper jaw

Mandibular Arch

lower jaw

Temporomandibular Joint (TMJ)

location where maxillary and mandibular arches meet at the back of the mouth

Dentition

natural teeth arranged on the jaws

Incisors and Canines

biting and tearing

Premolars (bicuspids) and Molars

chewing and grinding

Deciduous Dentition (baby teeth)

20 teeth during childhood that are replaced by 32 permanent dentition (adult teeth)

Occlusion

contact between chewing surfacs of upper and lower teeth

Crown

tooth visible in the mouth

• covered with enamel, the hardest substance in the body

Roots

hold teeth firmly in place within the dental arch

• protected cementum

Cervix

location where crown and root meet

Dentin

makes up most of the tooth

Pulp Cavity

location where crown and roots of the tooth are surrounded by dentin

• continues into root canals in the roots

Pulp

rich supply of blood vessels and nerves for nutrients

Saliva

clorless liquid that maintains moisture in the mouth

• maintains tooth health and begins digestive process

Salivary Glands

secrete saliva

Parotid Glands

on the face in front of each ear

Sublingual Glands

floor of the mouth under the tongue

Submandibular Glands

floor of the mouth near the mandible

The Pharaynx

passageway for respiration and digestion

• plays a role in deglutition (swallowing)

The Esophagus

muscular tube that ingested food passes through

Lower Esophageal (cardiac) Sphincter

muscular ring between esophagus and stomach

• relaxes to open and allow entry of food

Regurgitation

backwards flow of stomach contents

The Stomach

sac-like organ

Fundus

upper, rounded part

Body

main portion

Antrum

lower part

Rugae

folds in the mucosa lining of the stomach allowing for flexibility

Gastric Juices

aids in food digestion

Pyloric Sphincter

ring-like muscle that controls the flow of food to the duodenum

Pylorus

narrow passage that connects stomach with small intestine

The Small Intestine

coiled organ up to 20 feet

Duodenum

first portion of the small intestine

Jejunum

middle portion of the small intestine

Ileum

last and longest portion of the small intestine

The Large Intestine

wider but shorter than the small intestine

• waste products of digestion are processed

Cecum

pouch on the right side of abdomen

Ileocecal Sphincter

ringly-like muscle that controls flow from ileum to cecum

(Vermiform) appendix

hangs from the lower portion of the cecum

Colon

longest portion of the largest intestine

Ascending Colon

travels up from the cecum to the undersurface of the liver

Transverse Colon

pauses horizontal right to left toward th spleen

Decending Colon

travels down the left side to the sigmoid colon

Sigmoid Colon

s-shape structure that joins the descending colon to the rectum

Anorectal

anus and rectum as a single unit

Rectum

widest division of the large intestine (4 inches)

Anus

lower opening of the digestive tract

• flow of waste controlled by the internal and external anal sphincters

Accessory Digestive Organs

not part of the GI tract

Liver

lagest organ in the body

• removes toxins from the flood and extracting nutrients from food

• removes excess glucose and stories it as glycogen, a starch that can be converted back to glucose

Bilirubin (bile)

yellow/green fluid for fat digestion

Biliary Tree

channels through which bile is transported to the small intestine

• the cystic duct leaving the gallbladder joins the common hepatic duct to form the common bile dut, joining the pancreatic duct

Common Hepatic Duct

trunk of biliary tree ducts

Cystic Duct

bile exists and enters the gallbladder

Gallbladder

pear-shaped organ (egg-sized) under the liver

-stores and concentrates bile

Pancreas

soft, 6-inch long gland behind the stomach

• secretes pancreatic juices for digestion; secreted through the pancreatic duct

Digestion

process by which foods and broken down into nutrients

Digestive Enzymes

responsible for breaking down foods

Nutrient

substance necessary for normal functioning

Metabolism

processes involved in nutrient use

Anabolism

building up of body cells and substances from nutrients

Catabolism

breaking down of body cells and substances

Adsorption

process by which nutrients are transported to cells

Villi

lines the small intestine

• absorbs nutrients into the bloodstream

Lacteals

absorb fat and fat-soluble vitamins for transportion via lymphatic vessels

Digestion in Stomach

gastric juices begin digestion

Chyme

semifluid mass of aprtially digested food

Digestion in Small Intestine

• emulsification

• jejunum secretes digestive enzymes

• ileum absorbs nutrients

Digestion in Large Intestine

recieves and stores waste products

• excess liquid reabsorbed

• contains billions of mostly harmless bacteria, producing gas

Feces (solid body waste)

expelled via defecation (bowel movement [BM])

Borborygmus

rumbling noise caused by gas in the intestine

Flatulence (flatus)

passage of gas through the rectum

Mastication (chewing)

breaks food down into smaller pieces

Bolus

mass of food ready to be swallowed

Peristalsis

wave-like contractions that move food down the esophagus

Bariatrics

branch of medicine for control of obesity

Dentist

diagnoses and treats diseases of the teeth and oral cavity

Gastroenterologist

diagnoses and treats disorders of the stomach and intestines

Oral (maxillofacial) Surgeon

performs face and jaw surgeries

Orthodontist

prevents of correct malocclusion of the teeth and facial structures

Periodontist

prevents and treats disorders of tissues surrounding the teeth

Proctologist

specializes in disorders of the colon, rectum, and anus

Aphthous Ulcers (canker sores; mouth ulcers)

pits in soft tissues lining the mouth

Ulcer

open lesion of the skin or mucous membrane