Ch 3 - The Human Body: Are We Really What We Eat? Flashcards
Cell
The smallest unit of matter that exhibits the properties of living things, such as growth, reproduction, and metabolism.
Enterocytes
The cells lining the wall of the intestine.
Cell membrane
The boundary of an animal cell that separates its internal cytoplasm and organelles from the external environment.
Cytoplasm
The interior of an animal cell, not including its nucleus.
Organelle
A tiny “organ” within a cell that performs a discrete function necessary to the cell.
Tissue
A grouping of like cells that performs a function; for ex: muscle tissue.
Organ
A body structure composed of 2/more tissues and performing a specific function; for ex: the esophagus.
System
A group of organs that work together to perform a unique function; for ex: the gastrointestinal system.
Hunger
A physiological drive for food
Anorexia
An absence of appetite
Hypothalamus
A region of the forebrain above the pituitary gland, where visceral sensations, such as hunger and thirst are regulated.
Hormone
A chemical messenger secreted into the bloodstream by one of the many glands from the body, which acts as a regulator of physiological processes at a site remote from the gland that secreted it.
Digestion
The process by which foods are broken down into their component molecules, either mechanically or chemically.
Absorption
The physiological process by which molecules of food are taken form the gastrointestinal tract into the circulation.
Elimination
The process by which undigested portions of food and waste products are removed from the body.
Gastrointestinal (GI) tract
A long, muscular tube consisting of several organs: the mouth, esophagus, stomach, small intestine, and large intestine.
Sphincter
A tight ring of muscle separating some of the organs of the GI tract and opening in response to nerve signal indicating that food is ready to pass into the next section.
Cephalic phase
The earliest phase of digestion, in which the brain thinks about and prepares the digestive organs for the consumption of food.
Saliva
A mixture of water, mucus, enzymes, and other chemicals that moistens the mouth and food, binds food particles together, and begin the digestion of carbohydrates.