Chapter 4 all

Gastroenterology

The medical specialty that studies the anatomy and physiology of the gastrointestinal system

Oral Cavity

The mouth; the first part of the gastrointestinal tract containing teeth, gums, and tongue

Teeth

Structures within the mouth used for tearing, chewing, and grinding food

Gums

The firm connective tissue surrounding the base of the teeth

Tongue

A large muscle filling the oral cavity that moves food and contains taste receptors

Hard Palate

The bony front portion of the roof of the mouth

Soft Palate

The fleshy back portion of the roof of the mouth near the throat

Uvula

The fleshy structure hanging from the soft palate that helps sense food particles and saliva

Parotid Glands

A pair of large, flat salivary glands located on either side of the face, front of the ear

Sublingual Glands

A pair of salivary glands located directly below the tongue

Submandibular Glands

A pair of salivary glands located on either side of the neck, below the lower jawbone

Pharynx

The throat; a common passageway for inhaled air, exhaled air, and food

Nasopharynx

The uppermost part of the pharynx located behind the nasal cavity

Oropharynx

The middle portion of the pharynx located behind the oral cavity

Laryngopharynx

The lowermost portion of the pharynx located just superior to the larynx

Larynx

The voice box; a structure that remains open during breathing but closes during swallowing

Epiglottis

A lid-like structure that seals the larynx during swallowing to divert food to the esophagus

Esophagus

A muscular tube connecting the pharynx to the stomach that moves food via peristalsis

Stomach

An elongated muscular sac that stores, mixes, and digests food contents

Cardia

The small area where the stomach joins the esophagus

Fundus

The rounded, dome-shaped upper portion of the stomach

Body of Stomach

The large, curved central region of the stomach

Pylorus

The narrow, last section of the stomach that connects to the small intestine

Rugae

Thick, deep folds within the gastric mucosa that expand as the stomach fills

Chyme

A semi-liquid mixture of food, saliva, and gastric enzymes that leaves the stomach

Lower Esophageal Sphincter

A muscular ring located between the esophagus and the stomach that prevents acid reflux

Pyloric Sphincter

A muscular ring located between the stomach and the small intestine controlling food release

Small Intestine

A long, narrow tube consisting of the duodenum, jejunum, and ileum where digestion and absorption occur

Villi

Thousands of microscopic, finger-like protrusions that increase intestinal surface area for absorption

Lumen

The open central space or channel within a tubular organ like an intestine

Duodenum

The C-shaped first segment of the small intestine, about 10 inches long

Jejunum

The middle segment of the small intestine, about 8 feet long

Ileum

The third and final segment of the small intestine, about 12 feet long

Large Intestine

A wide tube running from the small intestine to the outside of the body that turns waste into feces

Cecum

A short, blind pouch forming the first part of the large intestine

Appendix

A small, worm-like structure attached directly to the cecum

Ileocecal Valve

A muscular valve that prevents waste material from backing up into the small intestine

Colon

The second and largest part of the large intestine, containing four main sections

Haustra

Puckered pouches along the walls of the colon that expand to hold digested waste material

Ascending Colon

The portion of the colon that travels upward along the right side of the abdomen

Transverse Colon

The portion of the colon that crosses horizontally across the upper abdomen

Descending Colon

The portion of the colon that travels downward along the left side of the abdomen

Sigmoid Colon

The S-shaped final section of the colon leading into the rectum

Rectum

The third and straight segment of the large intestine connecting to the body surface

Anus

The external opening of the rectum through which solid waste is eliminated

Anal Sphincter

A voluntary ring of muscle that controls the release of feces from the rectum

Peritoneum

A specialized membrane lining the abdominopelvic cavity that secretes lubricating fluid

Omentum

A fatty membrane extending from the peritoneum that supports and protects abdominal organs

Mesentery

A fan-shaped fold of peritoneum that supports and anchors the jejunum and ileum

Liver

The largest solid organ in the body, located in the RUQ, whose cells continuously produce bile

Hepatocytes

Specialized liver cells responsible for the continuous production of bile

Bile

A yellow-green digestive fluid produced by the liver containing acids, bilirubin, and biliverdin

Biliary Tree

The branching network of bile ducts that transports bile from the liver to the duodenum

Gallbladder

A teardrop-shaped green sac posterior to the liver that concentrates and stores bile

Pancreas

A yellow, triangular organ posterior to the stomach that secretes digestive enzymes and insulin

Pancreatic Duct

The central tube that transports digestive enzymes from the pancreas into the duodenum

Mechanical Digestion

Physical breakdown of food involving movement, such as mastication, deglutition, and peristalsis

Mastication

The physical process of tearing, chewing, and grinding food with the teeth

Deglutition

The physiological act of swallowing food or liquids

Peristalsis

Coordinated, wave-like muscular contractions that move food along the GI tract

Chemical Digestion

The chemical breakdown of food utilizing digestive enzymes, stomach acids, and bile

Amylase

A digestive enzyme in saliva and pancreatic juice that breaks down carbohydrates

Hydrochloric Acid

A strong acid in the stomach that breaks down food fibers and activates pepsinogen

Pepsin

A stomach enzyme activated by hydrochloric acid that breaks down protein molecules

Gastrin

A digestive hormone that stimulates gastric glands to secrete hydrochloric acid and pepsinogen

Intrinsic Factor

A gastric substance necessary to help the body absorb Vitamin B12 from foods

Cholecystokinin

An intestinal hormone that stimulates gallbladder contractions and pancreatic enzyme secretion

Emulsification

The process of bile physically breaking down large fat globules into smaller drops

Lactase

An enzyme produced by the jejunum that breaks down milk sugars into glucose

Lipase

A pancreatic enzyme that breaks down small fat drops into usable fatty acids

Absorption

The physiological process by which water and nutrients move into the bloodstream

Elimination

The final process of removing undigested fibers, water, and solid waste from the body

Feces

Solid body waste matter eliminated through the anus; also called stool or a bowel movement

Defecation

The bowel action of eliminating solid waste from the body

Flatus

Intestinal gas that accumulates in the GI tract and sometimes accompanies feces

Anorexia

A clinical decrease in appetite caused by disease or as a medication side effect

Heartburn

Temporary irritation and burning sensation in the esophagus due to refluxed stomach acid

Esophageal Varix

A dilated, swollen, and protruding vein located in the esophageal mucosa

Nausea

An unpleasant, queasy feeling in the stomach that often precedes vomiting

Vomiting

The forceful expulsion of stomach contents upward through the mouth

gastroenterology

the medical specialty that studies the anatomy and physiology of the stomach and intestines

gustatory

pertaining to or having the function of the sense of taste

gastric

pertaining to the stomach

cholecysto

combining form built from bile and sac meaning gallbladder

cholangio

combining form built from bile and vessel meaning bile duct

choledocho

combining form built from bile and receptacle meaning common bile duct

anorexia

condition or state of being without an appetite

dysphagia

condition of painful or difficult eating and swallowing

polyphagia

condition of excessive overeating

glossitis

infection or inflammation of the tongue

sialolithiasis

abnormal condition or process of having a stone in a salivary gland or duct

dyspepsia

condition of abnormal, difficult, or painful digestion; indigestion

gastritis

infection or inflammation of the stomach

gastroenteritis

acute infection or inflammation of the stomach and the intestines

gastroesophageal

pertaining to the stomach and the esophagus

gastroesophageal reflux disease (GERD)

chronic irritation due to the failure of the esophageal sphincter, allowing stomach acid to backflow

hematemesis

the forced vomiting of blood

peptic

pertaining to digestion

peptic ulcer disease (PUD)

chronic irritation, burning pain, and erosion of the mucosa layer due to an ulcer