Digestion and the Digestive System

Practice flashcards covering the vocabulary, organs, and processes of the human digestive system, including common digestive disorders.

Digestion

The chemical and physical breakdown of food/drink into a form the body can absorb as nutrients for energy.

Alimentary Canal

The digestive tract consisting of 8 metres of tubing including the mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus.

Ingestion

The taking in of food or beverages into the body through the mouth.

Mastication

The process of chewing food.

Amylase

An enzyme found in saliva and the stomach that breaks down carbohydrates into simple sugars.

Bolus

A ball of food passed through the digestive system, formed by saliva lubricating and binding the food.

Pharynx

A common passageway for food, liquids, and air that directs food from the mouth toward the esophagus.

Epiglottis

A flap that closes when swallowing to protect the airway and ensure food goes down the correct tube.

Peristalsis

The process of muscular contractions in the esophagus and digestive tract that pushes food toward the stomach.

Upper Esophageal Sphincter

A muscular valve that allows passage from the mouth to the esophagus and prevents backflow.

Trachea

The pipe leading to the lungs used for breathing.

Cardiac Sphincter

Also known as the lower esophageal sphincter; it prevents backflow of acid or food from the stomach into the esophagus.

Liver

An organ that manufactures bile, processes nutrients absorbed from the small intestine, breaks down toxins, and stores glycogen.

Bile

A greenish liquid manufactured by the liver and stored in the gallbladder that helps in the digestion of fats.

Stomach

An organ that churns and grinds food into a liquid mass using enzymes, fluids, and $HCl$.

Protease/pepsin

Enzymes in the stomach responsible for the breakdown of proteins.

Gastric lipase

Enzymes in the stomach responsible for the breakdown of fats.

Chyme

The thick fluid that food is converted into after being churned and mixed in the stomach.

Pancreas

An organ that secretes enzyme-rich juice to reduce food to molecules and releases insulin to neutralize acidic stomach fluid.

Insulin

A hormone that regulates the amount of glucose in the blood.

Glucagon

A hormone that helps to break down glycogen into glucose for glucose control.

Pyloric Sphincter

The valve that allows the passage of food from the stomach to the small intestine a little at a time.

Small Intestine

An organ approximately $10\,\text{feet}$ in length where the majority of digestion and absorption occur.

Villi

Numerous folds within the small intestine designed to assist in absorption.

Microvilli

Projections on the villi that are each designed to absorb one specific nutrient.

Duodenum

The first subdivision of the small intestine where most digestion takes place.

Jejunum

The middle subdivision of the small intestine primarily responsible for nutrient absorption.

Ileum

The final subdivision of the small intestine primarily responsible for nutrient absorption.

Ileocecal Valve

A sphincter that allows passage from the small intestine to the large intestine and prevents backflow.

Large Intestine

Also known as the colon; it reabsorbs excess water, compacts material into feces, and absorbs vitamins K and B12.

Rectum

The last portion of the digestive tract where feces are stored prior to elimination.

Anus

The opening at the end of the digestive tract that holds the rectum closed and opens for elimination.

Colitis

An inflammation of the colon or large intestine characterized by abdominal pain, diarrhea, and bloating.

Irritable bowel syndrome (IBS)

A condition characterized by abdominal pain, bloating, and irregular motility in the colon which may cause spasms.

Heartburn

A painful sensation behind the breastbone caused by the reflux of stomach contents into the esophagus.

Ulcers

An erosion of the top layer of cells in the stomach or duodenum that exposes underlying layers to gastric juices.