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Abdominal anatomical region

9-region plan: by means of four imaginary planes, two of which are horizontal (indicated by lines drawn across the right and left tenth ribs and across the right and left anterior superior iliac spines) and two sagittal (indicated by lines drawn from the mid-point of the inguinal ligament to the nipples of the chest or mid-point of the clavicle, right and left side

4-region plan: by means of two imaginary planes, one horizontal and the other mid-sagittal


Abdominal cavity

the cavity containing the abdominal organs; lying between the diaphragm and the pelvis


movement of a body part away from the midline of the body

ABO group

the red blood cell type determined by the presence or absence of A or B antigens on the red blood cell membrane; the four types are A, B, AB and O


localized accumulation of pus


the taking in of materials by cells or tissues

Accessory (auxiliary, assisting)

this term is applied to a lesser structure that resembles in structure and function a similar organ, as an example the accessory pancreatic duct

Achilles tendon

common tendon of the calf muscles that attaches to the heel (calcaneus); named after a mythical Greek warrior who was vulnerable only in the heel


condition characterized by a lower than normal blood pH (pH of 7.35 or lower)


inflammation of the sebaceous gland and hair follicles


presents itself after birth

Acquired immunity

immunity that is obtained after birth through the use of injections or exposure to a harmful agent

Acquired Immunodeficiency Syndrome (AIDS)

a specific group of diseases or conditions which are indicative of severe immunosuppression related to infection with the human immunodeficiency virus (HIV); infects helper T-cells; persons dead having had AIDS may exhibit conditions such as wasting syndrome, extra-pulmonary tuberculosis and Kaposi's sarcoma


hyperfunction of pituitary gland after ossification has been completed

Action potential

the changes of electrical charges on either side of a cell membrane in response to stimulus; depolarization followed by repolarization

Active immunity

the immunity provided by the production of antibodies after exposure to a foreign antigen; may be natural or artificial

Active transport

The process in which there is movement of molecules against a concentration gradient; that is from an area of lesser concentration to an area of greater concentration


A disease with a more or less rapid onset and short duration

Addison's disease

disease of the adrenal gland resulting in low blood sugar, low blood protein, weight loss and weakness


the movement of a body part toward the midline of the body


enlarged pharyngeal tonsil


the study of glands


benign tumor of the glandular epithelium

Adenosine Triphosphate (ATP)

chemical compound that provides energy for use of body cells


a cell of adipose tissue, specialized to store fat

Adipose tissue

a connective tissue composed primarily of adipocytes; functions as fat storage as a source of potential energy

Adrenal gland

a triangular body covering the superior surface of each kidney


synonym for epinephrine

Adrenocorticotropic hormone (ACTH)

a hormone produced by the anterior pituitary gland that stimulates the adrenal cortex to secrete cortisol


requiring oxygen


to carry toward a center or main point


intravascular; the increase in viscosity of blood brought about by the clumping of particulate formed elements in the blood vessels; a specific form of coagulation


a protein synthesized by the liver, which circulates in blood plasma; contributes to the colloid osmotic pressure of the blood


a hormone secreted by the adrenal cortex that increases the reabsorption of sodium and the excretion of potassium by the kidneys

Alimentary canal

the digestive system tube from the mouth to the anus, including the mouth or buccal cavity, pharynx, esophagus, stomach and small and large intestines


condition characterized by a higher than normal blood pH (pH of 7.45 or above)


having an acquired, abnormal (hypersensitive) immune response to a substance (allergen) that does not normally cause a reaction

Alpha cells

the cells of the islets of Langerhans of the pancreas that secrete the hormone glucagons

Alveolar process

bony ridge found on the inferior surface of the maxilla and the superior surface of the mandible that contains the sockets for the teeth

Alveolar type I cell

simple squamous epithelial cell that forms the walls of the alveoli of the lungs

Alveolar type II cell

the septal cells in the lungs that produce pulmonary surfactant


the air sacs of the lungs, made of simple squamous epithelium, in which gas exchange takes place

Alzheimer's disease

a progressive brain disease of unknown cause resulting in loss of memory, intellectual ability, speech and motor control


congenital absence of one or more limbs

Amino acid

building blocks of which proteins are constructed, and the end products of protein digestion or hydrolysis; their basic formula is NH2-CHR-COOH - an amino group (an alpha carbon, any aliphatic or aromatic radical and a carboxyl group)

Amniotic fluid

the fluid contained within the amnion; cushions the fetus and absorbs shock


A slightly moveable joint, such as a symphysis


a digestive enzyme that breaks down starch to maltose; secreted by the salivary glands and the pancreas


synthesis reactions in which smaller molecules are bonded together to form larger molecules; require energy (ATP) and are catalyzed by enzymes


in the absence of oxygen; not requiring oxygen


growth of abnormal cells, as in a tumor or neoplasm


generalized massive edema in subcutaneous tissue


a connection or joining especially of blood vessels

Anatomical guide

descriptive references for locating arteries and veins by means of the anatomical structures which are known

Anatomical position

the body is erect, feet together, palms facing forward and thumbs pointed away from the body


the structure of an organ, the branch of science dealing with the structure or organisms


a decrease in the number of erythrocytes, hemoglobin, or both


a localized dilation of a blood vessel


the study of vessels

Angle of the mandible

body angle formed by the junction of the posterior edge of the ramus of the mandible and the inferior surface of the body of the mandible


mutual opposition or contrary action; the inhibition of one bacteria by another

Anterior (ventral)

before or in front of, refers to the ventral or abdominal side of the body

Anterior nares

external nostril openings

Anterior superior iliac spine

a bony protuberance that can be palpated topographically, found on the ilium, the superior broad portion of the hip bone; the origin of the inguinal ligament and the sartorius muscle

Antibody (immunoglobulin)

glycoprotein substance developed in response to, and interacting specifically with, an antigen

Antidiuretic hormone (ADH)

a hormone produced by the hypothalamus and stored in the posterior pituitary gland; increases the reabsorption of water by the kidney tubules


a foreign substance that stimulates the formation of antibodies that interact specifically with it


the prevention or inhibiting of the growth of causative microorganisms


a protein synthesized by the liver that inactivates excess thrombin to prevent abnormal clotting


large elastic artery that is the main trunk of the systemic arterial system, which carries blood from the left ventricle of the heart and passes through the thorax and abdomen

Aortic semilunar valve

the valve at the junction of the left ventricle and the aorta; prevents backflow of blood from the aorta to the ventricle when the ventricle relaxes


impairment or absence of the ability to communicate in speech, reading or writing; may involve word deafness or word blindness

Aplastic anemia

failure of the red bone marrow resulting in decreased number of red blood cells, white blood cells and platelets; may be a side effect of some medications


failure of a tissue or an organ to develop normally

Apocrine gland

the type of sweat gland found primarily in the axilla and genital area; actually a modified scent gland

Appendicular skeleton

the bony structure that makes up the shoulder girdle, upper extremities, pelvis and lower extremities


watery, prepared with water as a solvent

Aqueous humor

clear, thin alkaline fluid that fills the anterior chamber of the eyeball


containing minute interspaces in a tissue

Areolar connective tissue

a tissue that consists of tissue fluid, fibroblasts, collagen and elastic fibers, and wandering wbc's; found in all mucous membranes and in subcutaneous tissue


an abnormal or irregular rhythm of the heart


disease of the arteries resulting in thickening and loss of elasticity of the arterial walls


the place of union between two or more bones; a joint


accumulation of free serous fluid in the abdominal cavity


a type of neuralgia that forms the blood-brain barrier to prevent potentially harmful substances from affecting brain neurons


fatty degeneration of thickening of the walls of the larger arteries occurring in atherosclerosis


a form of arteriosclerosis marked by the deposition of lipids in the inner layer of arterial walls

Atrioventricular bundle (AV bundle, bundle of His)

bundle of modified cardiac muscle fibers that projects from the AV node through the interventricular septum; conducts action potentials from the AV node rapidly through the interventricular septum

Atrioventricular node (AV node)

small collection of specialized cardiac muscle fibers located in the inferior part of the right atrium; functions to delay action potential transmission to the AV bundle

Atrioventricular valve (AV valve)

valve located between the atrium and the ventricle of the heart; the tricuspid valve between the right atrium and right ventricle; the bicuspid (mitral) valve between the left atrium and left ventricle


a wasting; decrease in size of an organ or tissue


dilution or weakening of virulence of a microorganism, reducing or abolishing pathogenicity


self-destruction of cells; decomposition of all tissues by enzymes of their own formation without microbial assistance

Autotrophic bacteria

self-nourishing bacteria that are capable of growing in the absence of organic compounds; organisms that obtain carbon from carbon dioxide


situated in or pertaining to an axis (a real or imaginary line that runs through the center of a body or about which a point revolves)

Axial skeleton

80 bones including the skull, vertebrae, thorax and hyoid bone


the cellular process of a neuron that carries impulses away from the cell body

Autopsy (necropsy)

a postmortem examination of the organs and tissue of a body to determine cause of death or pathological condition

Bacillus (bacilli)

rod shaped bacteria


the presence of bacteria in the blood


a prokaryotic one-celled microorganism of the Kingdom Monera, existing as free living organisms or as parasites, multiplying by binary fission and having a large range of biochemical properties

Bacterial colony

a visible group of bacteria growing on a solid medium, presumably arising from a single microorganism


an agent that destroys bacteria but not necessarily their spores


science that studies bacteria


mild in character or non-malignant; does not spread to distant sites

Beta cells

the cells of the islet of Langerhans of the pancreas that secrete the hormone insulin

Bilateral symmetry

the symmetry of paired organs, of an organisms whose right and left halves are mirror images of each other, or in which a median longitudinal section divides the organism into equivalent right and left halves


pertaining to bile

Biliary tract

the organs and ducts that participate in the secretion, storage and delivery of bile in the duodenum

Binary fission

a method of asexual reproduction involving halving of the nucleus and cytoplasm of the cell followed by the development of each half into a new individual


the process of removing tissue from living patients for diagnostic examination or a specimen obtained by biopsy

Biological vector

an arthropod vector in which the disease causing organism multiplies or develops within the arthropod prior to becoming infective for a susceptible individual


a membranous sac or receptacle for a secretion


thin vesicle on the skin containing liquid matter


tissue that circulates through the vascular system and is composed of approximately 22% solids and 78% water

Body of the mandible

horizontal portion of the lower jaw

Boil (furuncle)

acute, deep-seated inflammation in the skin which usually begins as a subcutaneous swelling in a hair follicle


relating to the cheek or mouth


to oxidize or to cause to be oxidized by fire or equivalent means; a tissue reaction or injury resulting from the application of heat, extreme cold, caustic material, radiation, friction or electricity


a general state of ill health, associated with emaciation; severe form of malnutrition


a narrow tube, channel or passageway


any malignant neoplasm marked by uncontrolled growth and spread of abnormal cells


a sheath or continuous enclosure around an organ or structure; the membrane that surrounds some bacterial cells; a loose gel-like structure that, in pathogenic bacteria, helps to protect against phagocytosis


several communicating boils of the skin and subcutaneous tissues with the production of discharge of pus and dead tissue


a cancer-causing chemical or material


a malignant tumor derived from epithelial tissue


the study of the heart

Carotid canal

a canal in the petrous portion of the temporal lobe that transmits the internal carotid artery and the internal carotid plexus of sympathetic nerves


a specialized type of dense connective tissue; attached to the ends of bones and forming parts of structures, such as nasal septum and the framework of the ear


formation of cavities in an organ or tissue; frequently seen in some forms of tuberculosis


situated at or pertaining to a center or central point


a large group of non-motile, gram negative intracellular parasites


funnel shaped openings, especially of the posterior nares; one of the communicating passageways between the nasal fossae and the pharynx

Chordae tendineae

tendinous strands running from the papillary muscles to the free margin of the cusps that make up the tricuspid and bicuspid valves; prevents the cusps of these valves from extending up into the atria during ventricular contraction


a disease with a more or less slow onset and long duration

Cleft palate

congenitally malformed palate with a fissure along the midline

Clinical pathology

study of disease by means of body secretions, excretions, and other body fluids performed in the laboratory in the diagnosis of a disease

Clostridium perfrigens

anaerobic, saprophytic, spore-forming bacterium, responsible for tissue gas; referred to as gas bacillus

Coccus (cocci)

a type of bacteria that is spherical or ovoid in form


the large intestine from the end of the cecum to the anal canal that surrounds the anus


the symbiotic relationship of two organisms of different species in which one gains some benefit such as protection or nourishment and the other is not harmed or benefitted


a disease that may be transmitted directly or indirectly from one individual to another


an unfavorable condition arising during the course of a disease


one of the three nasal conchae; a scroll-like bone


the immediate and temporary disturbance of brain function


a rounded protuberance at the end of the bone forming an articulation


existing at the time of birth or shortly thereafter


accumulation of an access of blood or tissue fluid in a body part

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