Any compound composed of atoms (some of which are carbon) held together by covalent (shared electron) bonds
A part of the body formed of two or more tissues and adapted to carry out a specific function; e.g. the stomach
Epithelium (epithelial tissue)
Pertaining to a primary tissue that covers the body surface, lines its internal cavities, and forms glands
Synthesis (combination) reaction
A chemical reaction in which larger, more complex atoms or molecules are formed from simpler ones
Negative feedback mechanisms
The most common of homeostatic control mechanisms. The net effect is that the output of the system shuts off the original stimulus or reduces its intensity.
Organ specialized to secrete or excrete substances for further use in the body or for elimination
Organic Compound composed of carbon, hydrogen, and oxygen; includes starches, sugars, cellulose.
System consisting of lymphatic vessels, lymph nodes, and other lymphoid organs and tissues; drains excess tissue fluid from the extracellular space and provides a site for immune surveillance.
RNA (Ribonucleic Acid)
Nucleic acid that contains ribose and the bases A,G,C, and U. Carries out DNA's instructions for protein synthesis.
The chromosomes, X and y, that determine genetic sex (XX=femal, XY=male); the 23rd pair of chromosomes
Fats and oils composed of fatty acids and glycerol; are the body's most concentrated source of energy fuel; also known as neutral fats.
Transverse (horizontal) section
A plane running from right to left, dividing the body into superior and inferior parts
The symbol for hydrogen ion concentration; a measure of relative acidity or alkalinity of a solution
The spreading of particles in a gas or solution with a movement toward uniform distribution of particles.
1. A cell or nerve ending of a sensory neuron specialized to respond to particular types of stimuli 2.) Molecule that binds specifically with other molecules e.g. neurotransmitters, hormones, and antigens.
A longitudinal (vertical) plane that divides the body or any of its parts into right and left portions.
Ionic compound that dissociates into charged particles (other than hydrogen or hydroxyl ions) when dissolved in water.
Chemical reaction in which a molecule is broken down into smaller molecules or its constituent atoms.
Nonliving material that separates the living cells in connective tissue consisting of ground substance and fibers.
(1) A thin layer or flat plate: (2) the portion of a vertebra between the transverse process and the spinous process.
A group of similar cells (and their intercellular substance) specialized to perform a specific function; primary tissue types of the body are epithelial, connective, muscle, and nervous tissue.
Substance composed of two or more different elements, the atoms of which are chemically united.
Frontal (coronal) section
Longitudinal (vertical) plane that divides the body into anterior and posterior parts.
System primarily responsible for water, electrolyte, and acid-base balance and removal of nitrogenous wastes.
Membrane, composed of three lamina layers, that encloses cell contents; outer limiting cell membrane.
Building block of nucleic acids; consists of a sugar, a nitrogen-containing base, and a phosphate group.
Process by which a large molecule is synthesized by covalently bonding smaller molecules together
The energy directly involved in moving matter; e.g., in bicycle riding, the legs provide the mechanical energy that moves the pedals.
A malignant, invasive cellular neoplasm that has the capability of spreading throughout the body or body parts.
Small cellular structures (ribosomes, mitochondria, and others) that perform specific metabolic functions for the cell as a whole.
The living animal (or plant), which represents the sum total of all its organ systems working together to maintain life.
Adenosine triphosphate (ATP)
Organic molecule that stores and releases chemical energy for use in body cells.
Membrane transport processes that do not require cellular energy (ATP), e.g., diffusion, which is driven by kinetic energy.
Reduction in size or wasting away of an organ or cell resulting from disease or lack of use.
DNA Deoxyribonucleic acid)
A nucleic acid found in all living cells; it carries the organism's hereditary information.
Membrane transport processes for which ATP is provided, e.g., solute pumping and endocytosis.
Long, whiplike extension of the plasma membrane of some bacteria and a sperm; propel the cell.
Complex substance containing carbon, oxygen, hydrogen, and nitrogen; composes 10% to 30% of cell mass.
Group of chemical substances including certain hormones and cholesterol; they are fat soluble and contain little oxygen.
An abnormal mass of proliferating cells; benign _____ remain localized; malignant _____ are cancers, which can spread to other organs.
Chemical substances, such as salts, acids, and bases, that ionize and dissociate in water and are capable of conducting an electrical current.
The structural and functional unit of living organisms; contains a nucleus and a variety of organelles enclosed by a limiting membrane.
The process of spontaneous decay seen in some of the heavier isotopes, during which particles or energy is emitted from the atomic nucleus; results in the atom becoming more stable
Extracellular material consisting of a basal lamina secreted by epithelial cells and a reticular lamina secreted by underlying connective tissue cells.
Exchange (displacement) reaction
Chemical reaction in which bonds are both made and broken; atoms become combined with different atoms.
A primary tissue; form and function vary extensively. Functions include support, storage, and protection.
Linear chains of carbon and hydrogen atoms (hydrocarbon chains) with an organic acid group at one end. A constituent of fat.
Different atomic forms of the same element, vary only in the number of neutrons they contain; the heavier species tend to be radioactive.
Positive feedback mechanisms
Feedback that tends to cause the level of a variable to change in the same direction as an initial change.
Chemical substances that do not contain carbon, including water, salts, and many acids and bases.
The energy of motion or movement, e.g., the constant movement of atoms, or the push given to a swinging door that sets it into motion.
The organ system consisting of the skeletal muscles of the body and their connective tissue attachments.
Tiny projections on the free surfaces of some epithelial cells; increase surface area for absorption.
The spread of cancer from one body part or organ into another not directly connected to it.
Organic compound containing nitrogen, carbon, hydrogen, and oxygen; building block of protein.
The one- or two-letter symbol used to indicate an element; usually the first letter(s) of the element's name
Dense spherical bodies in the cell nucleus involved with ribosomal subunit synthesis and storage.
One of a limited number of unique varieties of matter that composes substances of all kinds; e.g., carbon, hydrogen, oxygen.
Weak bond in which a hydrogen atom forms a bridge between two electron-hungry atoms. An important intramolecular bond.
Process during which the chromosomes are redistributed to two daughter nuclei; nuclear division. Consists of prophase, metaphase, anaphase, and telophase.
A group of organs that work together to perform a vital body function; e.g., the nervous system.
Diffusion of a solvent through a membrane from a dilute solution into a more concentrated one.
Epithelium (epithelial tissue)
Pertaining to a primary tissue that covers the body surface, lines its internal cavities, and forms glands.
One of the biological units of heredity located in chromatin; transmits hereditary information.
Membranes that form the linings of body cavities open to the exterior (digestive, respiratory, urinary, and reproductive tracts).
Tiny, smooth muscles attached to hair follicles; cause the hair to stand upright when activated.
Membrane that lines a cavity without an opening to the outside of the body (except for joint cavities); serosa
A sticky, thick fluid secreted by mucous glands and mucous membranes; keeps the free surface of membranes moist.
Double-layered capsule composed of an outer fibrous capsule lined by synovial membrane; encloses the joint cavity of a synovial joint.
Water-soluble protein found in the epidermis, hair, and nails that makes those structures hard and water-repellent; precursor is keratohyalin.
(1) flat, scalelike; (2) pertaining to flat, thin cells that form the free surface of some epithelial tissues.
Serous membrane lining the interior of the abdominal cavity and covering the surfaces of abdominal organs.
The less numerous type of sweat gland; produces a secretion containing water, salts, proteins,and fatty acids.
Two-layered serous membrane that lines the thoracic cavity and covers the external surface of the lung.
Skin and its derivatives; provides the external protective covering of the body.
Glands that have ducts through which their secretions are carried to a particular site.