Digestive System, Healthy Diet, and Related Health Issues

Vocabulary flashcards covering the human digestive system, its processes, supporting organs, nutrient groups, and related health disorders.

Digestive System

Body system that breaks down food into dissolved nutrients that are absorbed into the bloodstream and transported to cells throughout the body.

Ingestion

The first main digestive process, where food is taken into the body through the mouth by eating or drinking.

Digestion

The process of breaking down large, complex food particles into simpler, soluble food molecules that can be transported in the bloodstream.

Mechanical Digestion

The physical breakdown of food into smaller pieces by chewing in the mouth and churning or grinding in the stomach.

Chemical Digestion

The breakdown of food into smaller soluble molecules through mixing with digestive enzymes and hydrochloric acid.

Absorption

The movement of digested, soluble food molecules through the wall of the digestive system into the bloodstream.

Egestion

The process of eliminating undigested or unwanted food particles from the digestive tract as faeces through the anus.

Faeces

Undigested or unwanted waste food materials that are stored in the rectum and excreted through the anus.

Digestive Tract

A hollow, one-way duct about $9\,\text{m}$ long with two openings (mouth and anus) through which food passes during digestion.

Supporting Organs

Organs that assist in the digestive process without forming the main digestive tube, including the teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

Mouth

The oral cavity where ingestion occurs and where both mechanical and chemical digestion begin.

Teeth

Supporting organs in the mouth that tear, bite, chew, and crush moist food into a fine pulp.

Tongue

Muscular organ in the mouth that contains taste buds and rolls chewed food with saliva into a bolus for easier swallowing.

Salivary Glands

Supporting glands that secrete saliva into the mouth to moisten food and begin carbohydrate breakdown.

Saliva

Fluid produced by the salivary glands that moistens food into a bolus and contains enzymes that digest starch into sugar.

Bolus

A rounded, softened ball of chewed food mixed with saliva created by the tongue to make swallowing smoother.

Oesophagus

A long muscular tube located behind the trachea that carries the food bolus from the mouth down into the stomach.

Peristalsis

Rhythmic wave-like muscle contractions and relaxations along the digestive tract that push food forward.

Trachea

The windpipe structure located directly in front of the oesophagus.

Stomach

A muscular sac-like organ where swallowed food is stored for about $2\,\text{hours}$, pulverized, and mixed with gastric fluids.

Gastric Fluid

Digestive juices secreted by the stomach wall containing enzymes and hydrochloric acid.

Hydrochloric Acid

An acidic component of gastric fluid in the stomach that aids in chemical digestion.

Sphincter

A circular ring of muscle at the end of the stomach that opens to allow food to pass into the small intestine.

Small Intestine

A long, convoluted $6\,\text{m}$ tube adapted for completing food digestion and absorbing dissolved nutrients into the bloodstream.

Intestinal Juice

Fluid produced by glands in the small intestine wall containing enzymes to finalize digestion.

Large Intestine

A $1.5\,\text{m}$ long organ with a $70\,\text{mm}$ diameter where water, mineral salts, and certain vitamins are absorbed from undigested food.

Cecum

The widest opening segment of the large intestine where it connects to the small intestine.

Colon

The longest segment of the large intestine that absorbs water, minerals, and vitamins from digestive remnants.

Ascending Colon

The section of the colon that travels upward along the right side of the abdominal cavity.

Transverse Colon

The section of the colon that crosses horizontally across the abdomen.

Descending Colon

The section of the colon that travels downward along the left side of the abdomen.

Sigmoid Colon

The S-shaped portion of the large intestine connecting the descending colon to the rectum.

Rectum

The final part of the large intestine that stores faeces until they are eliminated from the body.

Anus

The muscular external opening at the end of the digestive tract through which faeces leave the body.

Liver

The body's largest internal organ; produces bile to assist in digesting fatty foods.

Bile

A yellow-green digestive fluid produced by the liver that breaks down fats.

Gallbladder

A pouch organ that temporarily stores bile produced by the liver until it is required for digestion.

Pancreas

An accessory organ that secretes pancreatic juices containing digestive enzymes into the digestive tract.

Pancreatic Juice

Enzyme-containing fluid produced by the pancreas that digests starches, proteins, carbohydrates, and fats.

Enzymes

Specialized chemicals that speed up the chemical breakdown of large food pieces into smaller molecules.

Amino Acids

The simple soluble units produced when proteins are broken down during digestion.

Fatty Acids and Glycerol

The simple soluble end-products resulting from the digestive breakdown of fats.

Diet

The combination of food and liquid eaten regularly by a human or organism.

Healthy Diet

A balanced intake of food providing all essential nutrients in the correct proportions.

Food Pyramid

A diagrammatic guide showing recommended daily portion sizes and food categories for a balanced diet.

Essential Nutrients

The $7$ foundational requirements of a healthy diet: proteins, carbohydrates, fats and oils, vitamins, minerals, fibre, and water.

Proteins

Nutrients essential for cellular growth, building new tissue, repairing worn tissues, and serving as reserve fuel.

Carbohydrates

Nutrients that serve as the main fuel source supplying energy and heat to body cells.

Fats and Oils

Nutrients providing concentrated fuel, reserve energy storage, nerve cell protection, and body organ insulation.

Vitamins

Organic regulatory substances that enhance chemical reactions, maintain health, prevent deficiency diseases, and boost disease resistance.

Minerals

Inorganic regulatory nutrients required for good health, normal growth, cellular function, and tissue development.

Fibre

Non-digestible carbohydrates that promote smooth food movement through the intestine, preventing constipation and reducing colon cancer risk.

Water

A vital liquid making up $75\%$ of the body that acts as a solvent and liquid medium for metabolic chemical reactions.

Unbalanced Diet

A diet with an excess or deficiency of specific food groups, leading to malnutrition or nutritional disorders.

Malnutrition

Harmful bodily condition caused by consuming too little food, too much food, or the wrong dietary proportion.

Undernourishment

Condition caused by consuming insufficient food amounts with too few nutrients.

Kwashiorkor

A severe nutritional disorder caused by a lack of dietary protein.

Anaemia

A deficiency disease caused by a lack of iron, producing weakness, fatigue, cold hands/feet, and shortness of breath.

Marasmus

A deficiency disease resulting from a extreme lack of energy foods like carbohydrates and fats.

Rickets

A vitamin deficiency condition caused by a lack of Vitamin D.

Scurvy

A deficiency disease caused by an insufficient intake of Vitamin C.

Overfeeding

The excessive intake of energy foods, which can result in obesity, tooth decay, heart disease, and diabetes.

Obesity

A state of health characterized by excess fat storage in tissues and cholesterol accumulation in arteries.

Cholesterol

Fatty substance that builds up inside arteries during obesity, leading to high blood pressure and potential heart failure.

Peptic Ulcers

Open sores in the stomach wall or upper intestinal tract, often caused by bacterial infection, smoking, painkillers, and stress.

Anorexia

A psychological eating disorder involving an extreme fear of gaining weight, leading to intentional self-starvation and severe physical harm.

Diarrhoea

Condition involving excretion of sparse, watery stool lasting around $2\,\text{days}$, caused by viruses, gastric flu, or bacterial infections.

Cholera

A dangerous bacterial infection spread through contaminated water that causes severe diarrhoea and dehydration.

Cirrhosis of the Liver

Irreversible scarring of liver tissue caused by continuous damage from excessive alcohol abuse or hepatitis C virus infection.

Duodenum

The first section of the small intestine directly connected to the stomach.