Digestive Terminology

Digestive system

The organs responsible for digestion, absorption, and elimination of food waste.

Gastrointestinal (GI) tract

The continuous digestive tube from mouth to anus.

Peristalsis

Rhythmic muscular contractions that move food through the digestive tract.

Bolus

A rounded mass of chewed food mixed with saliva.

Chyme

Semi-liquid mixture of partially digested food and gastric secretions in the stomach.

Mucosa

The innermost GI layer involved in secretion, absorption, and protection.

Submucosa

The connective tissue layer containing blood vessels, nerves, and glands beneath the mucosa.

Muscularis

The GI muscle layer responsible for movement and peristalsis.

Serosa

The outer protective layer of much of the digestive tract.

Esophagus

The muscular tube that carries swallowed food to the stomach.

Stomach

An organ that stores food and begins significant protein digestion.

Small intestine

The primary site of chemical digestion and nutrient absorption.

Duodenum

The first portion of the small intestine.

Jejunum

The middle portion of the small intestine and an important site of nutrient absorption.

Ileum

The final portion of the small intestine.

Large intestine

The digestive organ that absorbs water and forms feces.

Colon

The major portion of the large intestine.

Rectum

The final section of the large intestine that stores feces before elimination.

Liver

A large organ that processes nutrients, produces bile, detoxifies substances, and performs many metabolic functions.

Gallbladder

An organ that stores and concentrates bile.

Pancreas

An organ that produces digestive enzymes and hormones such as insulin.

Bile

A fluid produced by the liver that helps digest fats.

Amylase

An enzyme that breaks down carbohydrates.

Pepsin

A stomach enzyme that digests proteins.

Lipase

An enzyme that breaks down fats.

Protease

An enzyme that breaks down proteins.

Absorption

The movement of digested nutrients into blood or lymph.

Appendicitis

Inflammation of the appendix.

Gastroesophageal reflux disease (GERD)

A disorder in which stomach contents repeatedly flow back into the esophagus.

Gastritis

Inflammation of the stomach lining.

Peptic ulcer

A sore in the lining of the stomach or duodenum.

Gastroenteritis

Inflammation of the stomach and intestines, often caused by infection.

Celiac disease

An autoimmune disorder triggered by gluten that damages the small intestine.

Crohn disease

A chronic inflammatory bowel disease that can affect any part of the GI tract.

Ulcerative colitis

A chronic inflammatory bowel disease primarily affecting the colon and rectum.

Irritable bowel syndrome (IBS)

A functional GI disorder causing symptoms such as abdominal pain and altered bowel habits.

Diverticulosis

The presence of small pouches in the colon wall.

Diverticulitis

Inflammation or infection of diverticula.

Hemorrhoids

Swollen veins in the rectum or anus.

Cirrhosis

Progressive scarring of the liver that impairs its function.

Hepatitis

Inflammation of the liver.

Pancreatitis

Inflammation of the pancreas.

Cholelithiasis

Gallstones; hardened deposits in the gallbladder.

Jaundice

Yellowing of the skin and eyes caused by elevated bilirubin.

Constipation

Difficult or infrequent passage of stool.

Diarrhea

Frequent loose or watery stools.

Nausea

The sensation of needing or wanting to vomit.

Emesis

Vomiting.

Dysphagia

Difficulty swallowing.

Ascites

Abnormal accumulation of fluid in the abdominal cavity.

Muscular system

The muscles responsible for movement, posture, heat production, and internal organ functions.

Skeletal muscle

Voluntary, striated muscle attached primarily to bones.

Smooth muscle

Involuntary muscle found in organs and blood vessels.

Cardiac muscle

Involuntary striated muscle found in the heart.

Tendon

A strong connective tissue structure connecting muscle to bone.

Origin

The relatively fixed attachment point of a muscle.

Insertion

The attachment point of a muscle that generally moves during contraction.

Agonist

The primary muscle responsible for a particular movement.

Antagonist

A muscle that opposes the action of another muscle.

Atrophy

Shrinking or wasting of muscle tissue.

Hypertrophy

Increase in muscle size, usually due to enlargement of individual muscle fibers.

Muscle tone

Continuous, low-level contraction of skeletal muscles.

Muscle strain

An injury involving overstretching or tearing of a muscle or tendon.

Tendinitis

Inflammation or irritation of a tendon.

Tendinopathy

A disorder involving degeneration or dysfunction of a tendon.

Muscular dystrophy

A group of inherited disorders causing progressive muscle weakness and degeneration.

Myasthenia gravis

An autoimmune disorder causing weakness due to impaired communication between nerves and muscles.

Myalgia

Muscle pain.

Myopathy

A disease or disorder affecting muscle tissue.

Myositis

Inflammation of muscle tissue.

Spasm

Involuntary muscle contraction.

Cramp

A sudden, involuntary, often painful muscle contraction.

Contracture

Permanent shortening or tightening of a muscle or surrounding tissue that restricts movement.

Rhabdomyolysis

Rapid breakdown of skeletal muscle tissue that can release harmful substances into the blood.