Nutrition for Health & Health Care - Chapter 2: Digestion and Absorption

Digestion

The process by which complex food particles are broken down into smaller absorbable particles.

Gastrointestinal (GI) Tract

A flexible, muscular tube extending from mouth to anus, where digestion and absorption of nutrients occur.

Gastrin

A hormone secreted by cells in the stomach wall that stimulates the secretion of gastric acid.

Peristalsis

Successive waves of involuntary muscular contractions that push contents along the GI tract.

Segmentation

Periodic squeezing or partitioning of the intestine by circular muscles which mixes and pushes contents along.

Chyme

Partially digested food that is released from the stomach into the small intestine.

Lacteal

A lymphatic vessel in the villus of the small intestine that absorbs dietary fats.

Micronutrients

Nutrients needed in small amounts, including vitamins and minerals.

Villi

Fingerlike projections from the folds of the small intestine that absorb nutrients.

Microvilli

Tiny, hairlike projections on the surface of villi that trap and transport nutrients.

Digestive Secretions

Fluids secreted by digestive glands that aid in the breakdown of food.

Bile

An emulsifier produced by the liver and stored in the gallbladder, assisting in fat digestion.

Gallbladder

An organ that stores bile before it is released into the small intestine.

Pancreas

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

Foodborne Illness

Diseases caused by consuming contaminated food or drink.

Homeostasis

The maintenance of stable internal conditions in the body.

Prebiotics

Indigestible substances in foods that stimulate the growth of beneficial bacteria.

Probiotics

Live microorganisms that confer a health benefit when consumed in adequate amounts.

Malabsorption

A condition in which the body cannot absorb nutrients effectively from food.

Lipoproteins

Clusters of lipids and proteins that serve to transport lipids in the blood and lymph.

Chylomicrons

Lipoproteins that transport dietary lipids from the intestines to other locations in the body.

High-Density Lipoproteins (HDL)

Lipoproteins that transport cholesterol back to the liver from the body's tissues.

Low-Density Lipoproteins (LDL)

Lipoproteins that carry cholesterol and triglycerides from the liver to cells.

Very Low-Density Lipoproteins (VLDL)

Lipoproteins primarily composed of triglycerides that transport lipids to various tissues in the body.

Hydrochloric Acid (HCl)

A strong acid secreted by the stomach, important for digestion.

Enzyme

A protein that catalyzes chemical reactions in the body without being consumed in the process.

Salivary Amylase

An enzyme in saliva that begins the digestion of carbohydrates.

Intestinal Juice

The secretion from the intestinal glands containing enzymes for the digestion of carbohydrates and proteins.

Pancreatic Juice

The alkaline digestive secretion from the pancreas that contains enzymes for macronutrient digestion.

Digestive System

All the organs and glands associated with ingestion, digestion, and absorption of food.

Appendix

A small pouch located at the junction of the small and large intestines, often considered vestigial.

Rectum

The final section of the large intestine, leading to the anus.

Fiber

A type of carbohydrate that the body cannot digest, important for digestive health.

Esophagus

The muscular tube through which food passes from the throat to the stomach.

Sphincter

A ring-like muscle that controls the passage of substances between different parts of the digestive tract.

Nutrient Delivery

The process of transporting nutrients from the gastrointestinal tract to body cells.

Lymphatic System

A network of vessels that helps transport lymph, a fluid containing infection-fighting white blood cells.

Gastric Juice

The digestive fluid produced in the stomach, containing hydrochloric acid and digestive enzymes.

Carbohydrate

A macronutrient that is a major source of energy for the body.

Protein

A macronutrient composed of amino acids, essential for building and repairing tissues.

Fat

A macronutrient that provides a concentrated source of energy and is necessary for various bodily functions.

Triglycerides

The main form of fat stored in the body and in foods, composed of glycerol and fatty acids.

Lipid

A group of organic compounds, including fats, that are insoluble in water.

Transport of Nutrients

The process by which absorbed nutrients are distributed throughout the body.

Nutrient Absorption

The process by which nutrients pass from the digestive tract into the bloodstream or lymphatic system.

Energy-Yielding Nutrients

Nutrients that provide energy: carbohydrates, fats, and proteins.

GI Microbiota

The collection of microbes living in the gastrointestinal tract that aids in digestion.

Bicarbonate

An alkaline substance secreted by the pancreas to neutralize gastric acid in the small intestine.

Bile Acids

Compounds derived from bile that help in the emulsification and absorption of fats.

Nutritional Status

The condition of the body regarding its intake and utilization of nutrients.

Digestive Tract

The passage through which food travels, encompassing the mouth, esophagus, stomach, intestines, and anus.

Saliva

A fluid secreted by salivary glands, containing enzymes that aid in digestion.

Digestive Glands

Glands in the digestive system that secrete digestive enzymes and juices.

Chemical Messenger

A substance that transmits signals in the body, often in the form of hormones.

Appendicitis

An inflammation of the appendix, often requiring surgical removal.

Food Safety

Practices that prevent foodborne illnesses and ensure safe handling of food.

Epinephrine

A hormone that can influence digestion during stress responses.

Nutritional Deficiency

A state resulting from a lack of essential nutrients in the diet.

Liver

An organ that has multiple functions, including the production of bile and regulation of metabolism.

Glycogen

A form of stored glucose, primarily found in the liver and muscles.

Foodborne Infection

Illness caused by consuming food contaminated with pathogens.

Foodborne Intoxication

Illness caused by consuming toxins produced by pathogens in food.

Digestive Motility

The movement of food through the digestive tract facilitated by muscle contractions.

Hepatic Portal Vein

The vein that carries blood from the GI tract to the liver.