Chapter 3: Medical terminology
By Ilhami Kovanlikaya and Yi Wang
Of all the novel aspects one experiences when working in a hospital for the first time - the protocol, the attitude, the attire, the professional structure and rules - the medical vocabulary may be the most difficult to grasp. The dialogue of health care professionals may be so foreign to a new student that it initially sounds like another language. This is because the vast amount of medical vocabulary and terms, most of which are not used in colloquial speech, are essentially another language in themselves. A student new to the hospital setting is not expected to be an expert in medical vocabulary. However, students can profoundly enrich their hospital experience by learning several essential medical roots, vocabulary words, and terms, allowing them to go from unengaged bystanders to knowledgeable and active participants who are able to follow the medical dialogue.
3.1 Anatomical position and body planesAnatomical Position. In order to standardize terminology regarding the human body and its movements, anatomists have created a universal "anatomical position". In this position, the body is assumed to be standing, with the feet together, the arms palm forward on the side with the thumbs facing away from the body.
Cartesian 3D coordinate system is then used to describe the human body in the anatomic position (Fig.3.1). The xyz axes are defined as right-left, anterior-posterior, and superior-inferior. Corresponding xy plane is defined as the transverse (horizontal) plane; yz plane as the sagittal (median) plane, and xz plane as the coronal (frontal) plane.
Additionally, to describe the distance relationship relative to the body center, proximal and distal modifiers are used. To describe the distance relationship relative to the midline (z-axis in Fig.3.1), medial and lateral modifiers are used.
Medical terminology can be systematically comprehended according root word, prefix and suffix. Determination of the root meaning will usually establish the main thrust of the term. Root words are commonly derived from Greek or Latin source language. Prefixes are used to indicate location, number and time, and suffixes to indicate condition and process. When a medical term involves two or more body parts, individual root words are joined using the letter "o", as in cardiothoracic. Challenges in mastering medical terms include both Greek and Latin root words for the same organ, root words usually do not stand alone as complete words, and plural forms are in the source language.
It may be useful for students to have a crash course of study or a quick review of the commonly used Greek/Latin root words, prefixes and suffixes. These terms can be organized into two categories, 1) anatomic and medical (Table 3.1), and 2) relational (Table 3.2). Accordingly, the following two tables list root words, prefixes and suffixes commonly used in medicine for engineering students to have a quick study and reference.
The root "keys" from Tables 3.1&2 can be practiced by reviewing the medical vocabulary list in the Appendix.
Table 3.1. Anatomic and medical root words, prefixes and suffixes.
| Root, Pre/Suf-fix | Meaning | Example | Explanation |
| Limb and skeletal: | |||
| arth | joint | arthritis | joint inflammation |
| carpal | wrist | carpal tunnel syndrome | wrist nerve pain |
| chir | hand | chiropractic | (hand) manipulation of body structure |
| dactyl | finger | dactylography | finger print study |
| manus | hand | manubrium | handlike upper portion of sternum |
| my | muscle | myocardium | muscle in heart |
| oste | bone | osteoporosis | bone porous process |
| pedal | foot | pedestrian | walking people |
| pod | foot | podiatrist | foot doctor |
| tarsal | ankle | tarsal bones | bones in ankle |
| Head and neck: | |||
| audit | hear | auditory | of hearing |
| aur | ear | auriscope | device to look into the ear |
| bucc | cheek | buccopharyngeal fascia | cheek to pharynx connective tissue |
| caput | head | caput medusae | like medusa's head - enlarged paraumbilical vein |
| cereb | brain | cerebrum | brain (upper part) |
| cervic | neck | cervical | of neck |
| col(l) | neck | collar | around neck |
| corona | crown | coronary | like a crown |
| encephala | head | encephalitis | brain inflammation |
| hypno | sleep | hypnosis | sleep like state |
| lingu | tongue | linguistics | tongue work (speech) study |
| nas | nose | nasal | of nose |
| neuro | nerve | neurology | nerve system study |
| oculo | eye | ocular migraine | retinal disease accompanied by migraine headache |
| olfact | smell | olfactory | of smell |
| ophtalm | eye | optalmology | eye system and disease study |
| opia | vision | myopia | squint eye - nearsighted |
| ot | ear | otoscope | device to look into the ear |
| phasia | speech | dyphasia | malfunction/disorder in speech |
| psycho | mind | psychology | mind study |
| rhin | nose | rhinoplasty | nose plastic syrgery |
| somn | sleep | insomnia | inability to fall asleep |
| tact | touch | tactile | relating to touch sense |
| Body: | |||
| angi | vessel | angiography | vessel imaging |
| cardi | heart | cardiography | heart sudy |
| chol | bile | cholera | bile (gastrointestinal) symptom |
| corp | body | corpus | body (dead) collection of writing |
| coxal | hip | coxa | hip joint |
| cut | skin | cutaneous | of skin |
| derm | skin | dermatology | skin study |
| diure | urinate | diuretic | (increase) urination |
| emia | blood | anemia | laking blood |
| glute | buttock | gluteal | relating to buttock |
| hem | blood | hematoma | blood mass |
| hepat | liver | hepatitis | liver inflammation |
| hist | tissue | histology | tissue study |
| hyster | uterus | hysteroctomy | uterus excision |
| inguinal | groin | inguinal ligament | in inguinal canal, connecting the ilium to the pubic bone |
| lapar | abdomen | laparoscopy | abdomen exam |
| mamm | breast | mammography | breast imaging |
| mast | breast | mastectomy | breast excision |
| nephr | kidney | nephrology | kidney study |
| pneumon | lung/air | pneumonia | lung imflammation |
| pulmo | lung | pulmonary | relating to lung |
| ren | kidney | renal artery | artery supplying kidney |
| soma | body | somatization | conversion from mental to body pain |
| some | body | lysosome | looseing body-membrane bound cell |
| steth | chest | stethoscope | chest exam device (hearing chest sound) |
| thorac | chest | thoracic | of chest |
| vent | belly | bentral hernia | protrusion (througn a wall/connective tissue) of belly |
| viscero | organ | viscerosomatic | relating to both internal organ and outer body trunk |
| Medicine: | |||
| alg | pain | neuralgia | pain caused by a nerve |
| brady | slow | bradycardia | slow beating heart (<50bpm) |
| dys | improper, bad | dystrophy | abnormal growth |
| ectomy | excision/cut | endorectomy | cut from inside, as in carotid endorectomy |
| gangli | swelling, mass | ganglion | cell cluster in peripheral nervous system |
| iatr | medical care | podiatry | feet medical care |
| itis, ia | inflammation | dermatitis | skin inflammation |
| mal | bad | malignant | "badly bear", causing harm |
| neo | new | neoplasm | new creation (abnormal growth) - tumor |
| oma | growth | carcinoma | cancer of epithelial cells: growing body looking like a crab |
| onc | tumor | oncogenic | relating to tumor formation |
| osis | process | narcosis | sleep/death process: cell injury of premature death |
| path | disease | pathology | disease study |
| peps, pept | digestion | peptic | aiding digestion |
| scopy | examination | thoracoscopy | thoracic cavity examination |
| septi | rotten | antiseptic | opposing decay |
| tachy | rapid | tachycardia | fast beating heart (>100bpm) |
| therap | treatment | therapeutic | of treatment of desease |
| thromb | clot | thrombosis | blood clotting process |
| trauma | wound | traumatic | wounded |
| tox | poison | toxicology | poison study |
| zyme | ferment | enzyme | biological catalyst |
Table 3.2. Relational words, prefixes and suffixes.
| Root, Pre/Suf-fix | Meaning | Example | Explanation |
| a | lacking | anemia | lacking blood |
| ab | away form normal | abduct | move away form the median play |
| ac-, ad- | toward | accelerate, admittance |
celer-fast, mittere-send |
| ana | throughout | anatomy | throughout cut |
| ante | before | antebrachium | forearm |
| anti | against | antibiotics | against bacteria |
| apo | separation | apophysis | projecting part of an organ |
| bi | double | bicuspid | two cups |
| cata | down | catabolism | braking down molecules |
| cle, cula | diminutive | tubercle | small nodule |
| con, com | together | conjugate | link together |
| contra | opposite | contrlateral | opposite side |
| de | reduce | debug | remove bugs |
| di | apart | dissect | cut apart piece by piece |
| dia | through | diagnosid | knowledge through (studying symptom) |
| e, ex, extra | away from | excision | cut from outside (cise = cut) |
| ecto | outsude | ectoderm | outer germ layer |
| endo | inside | endocardium | inner layer of the heart |
| epi | upon, over | epidemic | upon people - spreading from persone to persone |
| fer, ferent | carry | afferent | carry toward |
| ger | old age | geriatrics | elderly medicine |
| graph | record | radiograph | x-ray image |
| gyn | female | genecology | female reproduyctive medicine |
| hyper | excessive | hyperextension | beyond normal |
| hypo | under | hypoglycemia | low sugal leve in blood |
| in | in | incision | cut from aside |
| infra | beneath | infraorbital | below the orbit |
| inter | between | intervertebral | between vertebrae |
| intra | within | intravenous | inside vein |
| ipsi | same | ipsilateral | same side |
| ject | throw | ejection | throwing out |
| kine | motion | akinesia | slowness from impared muscle |
| later | side | bilateral | two sides |
| leuk | white | leukemia | white blood cell increase |
| mes, medi, mid | middle | mesoderm | middle germ layer |
| meta | after | metacarpal | after the wrist |
| necr | dead | necrology | list of people died recently |
| oid | resembling | xiphoid | shaped like a sword |
| -ole, -olus | diminutive | malleolus | lttle hammer |
| ortho | straight | orthodontist | straightening teeth dentist |
| pan | all | panacea | a cure for all diseases |
| peri | around | peridontal | around tooth |
| plas/t/m | form | cytoplasm | cell substance |
| post | after | postnatal | after birth |
| pre | before | prenephron | before the final kidney |
| retro | behind | retrosternal | behind the sternum |
| rhod | red | rhodopsin | purple pigment in the retina |
| rrhea/age | discharge | hemorrhage | blood discharge |
| sclero | hard | artheriosclerosis | hardening of the arterial walls |
| se | apart | serum | liquid separated from blood |
| sub | beneath | subclavan | beneath the clavicle |
| super | above | suprasternal | above the sternum |
| trans | through | transurethral | through urethra |
Glossary. Basic medical terms.
A
abdomen: The part of the body between the diaphragm and pelvis containing the digestive organs.
abduction: The movement of a body part away from the axis or midline of the body.
absorption: The transport of molecules across epithelial membranes into the body fluids
acidosis: An increased acidity in the blood and other body tissue (i.e., an increased hydrogen ion concentration) that lowers the arterial pH to below 7.35.
acromegaly: The hypersecretion of growth hormone from the pituitary gland after maturity which causes enlargement of the extremities, such as the nose, jaws, fingers, and toes.
active transport: The movement of molecules or ions across a cell membrane in a direction against their concentration gradient. An expenditure of cellular energy (ATP) is required.
active immunity: Immunity involving sensitization, in which antibody production is stimulated by prior exposure to an antigen.
adduction: The movement of a body part toward the axis or midline of the body.
adenohypophysis: The anterior, glandular lobe of the pituitary.
adenoids: The tonsils; located in the nasopharynx.
adrenergic: A term used to describe the actions of epinephrine, norepinephrine, or other molecules with similar activity.
adventitia (serosa): The outermost epithelial layer of a visceral organ.
afferent: Bringing to or leading towards an organ or part (opposed to efferent).
alimentary canal (gastrointestinal tract): The tubular portion of the digestive tract.
allergy: A state of hypersensitivity caused by exposure to allergens. It results in the liberation of histamine and other molecules with histamine like effects.
alveolus: An individual air capsule within the lung which is the basic functional unit of respiration. The socket that secures a tooth (tooth socket).
ampulla: A saclike enlargement of a duct or tube.
anaphylaxis: A severe allergic reaction that can result in cardiovascular shock and death.
anastomosis: An interconnecting of blood vessels or nerves that form a network plexus.
anatomical position: An erect body stance with the feet together, the arms palm forward on the side with the thumbs facing away from the body.
anatomy: The branch of science concerned with the structure of the body and the relationship of its organs.
androgens: Steroids containing 18 carbons that have masculinizing effects; primarily those hormones (such as testosterone) secreted by the testes.
anemia: An abnormal reduction in the red blood cell count, hemoglobin concentration, or hematocrit, or any combination of these measurements.
angina pectoris: A thoracic pain, often referred to the left pectoral and arm area, caused by myocardial ischemia.
anterior (ventral): Toward the front; the opposite of posterior, or dorsal.
anterior pituitary: Adenohypophysis.
antibody: An Immunoglobin (Ig), a specialized protein secreted by B lymphocytes which is responsible for humoral immunity.
antigen: A molecule that can induce the production of antibodies and react in a specific manner with antibodies.
anus: The terminal opening of the GI tract.
aorta: The major systemic vessel of the arterial system of the body, emerging from the left ventricle.
apex: The tip or pointed end of a conical structure.
aphasia: Defects in speech, writing, or in the comprehension of spoken or written language caused by brain damage or disease.
appendix: A short pouch that attaches to the cecum that is a part of a large bowel.
arachnoid mater: The web-like middle covering (meninx) of the central nervous system.
arteriole: The smallest branches of an artery that lead to a capillary.
arteriosclerosis: Any one of a group of diseases characterized by thickening and hardening of the artery wall and the narrowing of its lumen.
arteriovenous anastomoses: Direct connections between arteries and veins that bypass capillary beds.
artery: A blood vessel that carries blood away from the heart.
atherosclerosis: A common type of arteriosclerosis found in medium and larger arteries in which raised
areas within the tunica intima are formed from smooth muscle cells, cholesterol, and other lipids. These plaques occlude arteries and serve as sites for the formation of thrombi.
atrium: Either of the two superior chambers of the heart that receive venous blood.
atrophy: A gradual wasting away or decrease in the size of a tissue or an organ.
auditory: Pertaining to the structures of the ear associated with hearing.
autonomic nervous system (ANS): The sympathetic and parasympathetic portions of the nervous system that function to control the actions of the visceral organs and skin.
axilla: The depressed hollow commonly called the armpit.
axon: The elongated process of a nerve cell that transmits an impulse away from the cell body of a neuron.
B
basal metabolic rate (BMR): The rate of metabolism (expressed as oxygen consumption or heat production) under resting or basal conditions.
basal nucleus (basal ganglion): A mass of nerve cell bodies located deep within a cerebral hemisphere.
benign: Not a threat to life or long-term health, not malignant.
bifurcate: Forked; divided into two branches.
bile: A liver secretion that is stored and concentrated in the gallbladder and released through the common bile duct into the duodenum. It is essential for the absorption of fats.
bilirubin: Bile pigment derived from the breakdown of the heme portion of hemoglobin.
blood-brain barrier (BBB): A specialized mechanism that inhibits the passage of certain materials from the blood into brain tissue and cerebrospinal fluid.
brachial plexus: A network of nerve fibers that arise from spinal nerves C5-C8 and T1 which supply the upper extremities.
bradycardia: A slow cardiac rate; fewer than 60 beats per minute.
brain stem: The portion of the brain consisting of the medulla oblongata, pons, and midbrain.
bronchus: A branch of the trachea that leads to a lung.
C
cancer: A tumor characterized by abnormally rapid cell division and the loss of specialized tissue characteristics, usually refers to malignant tumors.
capillary: A microscopic blood vessel that connects an arteriole and a venule; the functional unit of the circulatory system.
cardiac output: The volume of blood pumped per minute by either the right or left ventricle.
cardiogenic shock: Shock that results from low cardiac output in heart disease.
catabolism: The metabolic breakdown of complex molecules into simpler ones, often resulting in a release of energy.
catecholamines: A group of molecules including epinephrine, norepinephrine, L-dopa, and related molecules with effects similar to those produced by activation of the sympathetic nervous system.
cauda equine: The lower end of the spinal cord where the roots of spinal nerves have a tail-like appearance.
cell: The structural and functional unit of an organism; the smallest structure capable of performing all the functions necessary for life.
cell-mediated immunity: Immunological defense provided by T cell lymphocytes that come within close proximity of their victim cells (as opposed to humoral immunity provided by the secretion of antibodies by plasma cells).
central nervous system (CNS): Part of the nervous system consisting of the brain and the spinal cord.
cerebellum: The portion of the brain concerned with the coordination of skeletal muscle contraction.
cerebrospinal fluid (CSF): A fluid produced by the choroid plexus in the ventricles of the brain. It fills the ventricles and surrounds the central nervous system in association with the meninges.
cerebrum: The largest portion of the brain, composed of the right and left hemispheres.
cervical: Pertaining to the neck or a necklike portion of an organ.
cervix: The narrow necklike portion of an organ.
chemotaxis: The movement of an organism or a cell, such as a leukocyte, toward a chemical stimulus.
chiasma: A crossing of nerve tracts from one side of the CNS to the other.
cholesterol: A 27-carbon steroid that serves as the precursor of steroid hormones.
cholinergic: Denoting nerve endings that liberate acetylcholine as a neurotransmitter, such as those of the parasympathetic system.
choroid plexus: A mass of vascular capillaries from which cerebrospinal fluid is secreted into the ventricles of the brain.
chromosomes: Structures in the nucleus that contain the genes for genetic expression.
cilia: Microscopic hairlike processes that move in a wavelike manner on the exposed surfaces of certain epithelial cells.
circadian rhythms: Physiological changes that repeat at about 24-hour intervals. These are often synchronized with changes in the external environment, such as the day-night cycles.
circle of Willis (cerebral arterial circle): an arterial polygon as the internal carotid and vertebral systems anastomose around the optic chiasm and infundibulum of the pituitary stalk.
cirrhosis: Liver disease characterized by loss of normal microscopic structure, which is replaced by fibrosis and nodular regeneration.
collateral: A small side branch of a blood vessel or nerve fiber.
colon : Large intestine.
congenital: Present at the time of birth.
congestive heart failure: The heart fails to pump blood at a rate commensurate with the requirements of the metabolizing tissues as a result of heart disease or hypertension. This condition is associated with breathlessness, excessive tiredness and edema.
connective tissue: It is a binding and supportive tissue with abundant matrix.
contralateral: Taking place or originating in a corresponding part on the opposite side of the body.
conus medullaris: The inferior, tapering portion of the spinal cord.
cornea: The transparent, convex, anterior portion of the outer layer of the eyeball.
coronal plane (frontal plane): A vertical plane that divides the body into anterior (ventral) and posterior (dorsal) portions.
coronary circulation: The arterial and venous blood circulation to the wall of the heart.
corpus callosum: A large tract of white matter within the brain that connects the right and left cerebral hemispheres.
cortex: 1.The outer layer of an internal organ or body structure, as of the kidney or adrenal gland. 2. The convoluted layer of gray matter that covers the surface of each cerebral hemisphere.
corticosteroids: Steroid hormones of the adrenal cortex, consisting of glucocorticoids (such as hydrocortisone) and mineralocorticoids (such as aldosterone).
cranial: Pertaining to the cranium.
cranial nerves: One of 12 pairs of nerves that arise from the brain.
cranium: The bones of the skull that enclose or support the brain and the organs of sight, hearing, and balance.
Cushing's syndrome: Symptoms caused by the hypersecretion of adrenal steroid hormones as a result of tumors of the adrenal cortex or ACTH secreting tumors of the anterior pituitary.
cyanosis: A bluish discoloration of the skin or mucous membranes due to insufficient oxygen in the blood.
cytology: The science dealing with the study of cells.
cytoplasm: In a cell, the cell substance between the cell membrane and the nucleus, containing the cytosol, organelles, cytoskeleton, and various particles.
D
decussation: A crossing of nerve fibers from one side of the CNS to the other.
defecation: The elimination of feces from the rectum through the anal canal and out the anus.
dendrite: A nerve cell short process that transmits impulses toward a neuron cell body.
dermis: The second, or deep, layer of skin beneath the epidermis.
diabetes insipidus: A condition in which inadequate amounts of antidiuretic hormone (ADH) are secreted by the posterior pituitary. It results in the inadequate reabsorption of water by the kidney tubules; thus, in the excretion of a large volume of dilute urine.
diabetes mellitus: The appearance of glucose in the urine due to the presence of high plasma glucose concentrations, even in the fasting state. This disease is caused by either lack of sufficient insulin secretion or inadequate responsiveness of the target tissues to the effects of insulin.
diaphragm: A sheetlike dome of muscle and connective tissue that separates the thoracic and abdominal cavities.
diaphysis: The shaft of a long bone.
diarrhea: Abnormal frequency of defecation accompanied by abnormal liquidity of the feces.
diastole: The sequence of the cardiac cycle during which a heart chamber wall is relaxed.
diencephalon: A major region of the brain that includes the third ventricle, thalamus, hypothalamus, and pituitary gland.
digestion: The process by which larger molecules of food substance are broken down mechanically and chemically into smaller molecules that can be absorbed.
distal: Away from the midline or origin; the opposite of proximal.
diuretic: An agent that promotes the excretion of urine, thereby lowering blood volume and pressure.
DNA (Deoxyribonucleic acid): composed of nucleotide bases and deoxyribose sugar. It is found in all living cells and contains the genetic code.
dorsal: Pertaining to the back or posterior portion of a body part; the opposite of ventral; also called posterior.
dorsiflexion: Movement at the ankle as the dorsum of the foot is elevated.
duodenum: The first portion of the small intestine that leads from the pylorus of the stomach to the jejunum.
dura mater: The outermost meninx covers the central nervous system.
dyspnea: Difficulty in breathing.
E
ECG: Electrocardiogram.
edema: An excessive accumulation of fluid in the body tissues.
efferent: Conveying away from the center of an organ or structure.
efferent neuron: Motor neuron.
electrocardiogram: A recording of the electrical activity that accompanies the cardiac cycle; ECG or EKG.
electroencephalogram (EEG): A recording of the brainwave patterns or electrical impulses of the brain from electrodes placed on the scalp.
electromyogram: A recording of the electrical impulses or activity of skeletal muscles using surface electrodes; EMG.
embryology: The study of prenatal development from conception through the eighth week in utero.
emphysema: A lung disease in which the alveoli are destroyed and the remaining alveoli become larger. It results in decreased vital capacity and increased airway resistance.
endocardium: The endothelial lining of the heart chambers and valves.
endocrine gland: A ductless, hormone-producing gland that is part of the endocrine system.
endogenous: Denoting a product or process arising from within the body (as opposed to exogenous products or influences from external sources).
endorphins: A group of endogenous opiate molecules that may act as a natural analgesic.
endothelium: The layer of epithelial tissue that forms the thin inner lining of blood vessels and heart chambers.
enteric: The term referring to the small intestine.
enzyme: A protein catalyst that increases the rate of specific chemical reactions.
eosinophil: A type of white blood cell characterized by the presence of cytoplasmic granules that become stained by acidic eosin dye.v epidermis: The outermost layer of the skin, composed of several stratified squamous epithelial layers.
epidural space: A space between the spinal dura mater and the bone of the vertebral canal.
epiphysis: The end segment of a long bone, separated from the diaphysis early in life by an epiphyseal plate but later becoming part of the larger bone.
epithelial tissue: One of the four basic tissue types; the type of tissue that covers or lines all exposed body surfaces
erythrocyte: A red blood cell.
esophagus: A tubular portion of the GI tract that leads from the pharynx to the stomach as it passes through the thoracic cavity.
essential amino acids: Those eight amino acids in adults or nine amino acids in children that cannot be made by the human body; therefore, they must be obtained in the diet.
estrogens: Any of several female sex hormones secreted from the ovarian (graafian) follicle.
etiology: The study of cause, especially of disease, including the origin and what pathogens, if any, are involved.
eustachian canal: Auditory tube.
exocrine gland: A gland that secretes its product to an epithelial surface, directly or through ducts.
expiration: The process of expelling air from the lungs through breathing out; also called exhalation.
extension: A movement that increases the angle between parts of a joint.
external: Located on or toward the surface.
extrinsic: Pertaining to an outside or external origin.
F
falx cerebri: A fold of dura mater which extends between the right and left cerebral hemispheres.
fascia: A tough sheet of fibrous tissue binding the skin to underlying muscles or supporting and separating muscles.
fasciculus: A small bundle of muscle or nerve fibers.
feces (gaita): Material expelled from the large bowel during defecation, composed of undigested food residue, bacteria, and secretions; also called stool.
fertilization: The fusion of an ovum and spermatozoon.
fetus: An unborn human after 8 weeks of development.
fibrillation: A condition of rapid, irregular, and uncoordinated contraction of muscle fibers. If it occurs in the ventricles of the heart resulting in the inability of the myocardium to contract as a unit and pump blood, it can be fatal.
fibrin: The insoluble protein formed from fibrinogen by the enzymatic action of thrombin during the process of blood clot formation.
filum terminale: A fibrous, threadlike continuation of the pia mater, extending inferiorly from the terminal end of the spinal cord to the coccyx.
fissure: A groove or narrow cleft that separates two parts, such as the cerebral hemispheres of the brain.
flexion: A movement that decreases the angle between parts of a joint.
foramen, pl. foramina: An opening in an anatomical structure, usually in a bone, for the passage of a blood vessel or a nerve.
fossa: A depressed area, usually on a bone.
fourth ventricle: A cavity filled with cerebrospinal fluid which is located in the brain stem between the cerebellum and the medulla oblongata and the pons.
frontal: 1.the bone of the skull forming forehead. 2. A plane through the body, dividing the body into anterior and posterior portions; also called the coronal plane.
G
gallbladder: A pouchlike organ attached to the underside of the liver in which bile secreted by the liver is stored and concentrated.
ganglion: An aggregation of nerve cell bodies occurring outside the central nervous system.
gastrointestinal tract (GI tract): The portion of the digestive tract that includes the stomach, the small and large intestines.
gigantism: Abnormal body growth as a result of the excessive secretion of growth hormone.
gland: An organ that produces a specific substance or secretion.
glomerular filtration rate (GFR): The volume of filtrate produced per minute by both kidneys.
glomerulonephritis: Inflammation of the renal glomeruli, associated with fluid retention, edema, hypertension, and the appearance of protein in the urine.
glomerulus: A coiled tuft of capillaries surrounded by the glomerular capsule that filtrates urine from the blood.
glucocorticoid (corticosteroid): A steroid hormone secreted by the adrenal cortex which affects the metabolism of carbohydrates and to a lesser extend proteins and fats. It also has anti-inflammatory and immunosuppressive effects. Hydrocortisone (cortisol) is the major glucocorticoid in humans.
glycolysis: A complex biological process that occurs to convert glucose into pyruvic acid in order to provide energy for each living cell.
glycosuria: The excretion of an abnormal amount of glucose in the urine.
gonad: A reproductive organ, testis or ovary, that produces gametes and sex hormones.
gray matter: The major component of the central nervous system composed of nerve cell bodies and their dendrites (mostly unmyelinated nerve tissue).
growth hormone: A hormone secreted by the anterior pituitary that stimulates growth of the body that influences the metabolism of protein, carbohydrate, and fat throughout life.
gyrus: A convoluted elevation or ridge.
H
hay fever: A seasonal type of allergic rhinitis caused by pollen; it is characterized by itching and tearing of the eyes, swelling of the nasal mucosa, attacks of sneezing, and asthma.
heart murmur: An extra or unusual auscultatory sound heard during a heartbeat as a result of structural defects of the valves or septum.
hematocrit: The ratio of packed red blood cells to total blood volume in a centrifuged sample of blood, expressed as a percentage.
heme: The iron-containing red pigment that, together with the protein globin, forms hemoglobin.
hemoglobin: The iron-containing oxygen-transport metalloprotein in the red blood cells that transports oxygen.
hemopoiesis (hematopoiesis): The production of red blood cells.
heparin: A mucopolysaccharide that prevents clots in the blood vessels.
hepatitis: Inflammation of the liver.
hiatus: An opening or fissure; a foramen.
high-density lipoproteins (HDLs): The carrier protein for lipids, such as cholesterol, that appear to offer some protection from atherosclerosis.
hilum (hilus): A concave or depressed area where vessels or nerves enter or exit an organ.
histamine: A compound that stimulates vasodilation and increases capillary permeability. It is responsible for many of the symptoms of inflammation and allergy.
histology: Microscopic anatomy of the structure and function of tissues.
homeostasis: The dynamic constancy of the internal environment, the maintenance of which is the principal function of physiological regulatory mechanisms.
horizontal (transverse) plane: A directional plane that divides the body, organ, or appendage into superior and inferior or proximal and distal portions.
hormone: A chemical substance produced in an endocrine gland and secreted into the bloodstream to cause an effect in a specific target organ.
humoral immunity (antibody-mediated immunity): The form of acquired immunity in which antibody molecules are secreted in response to antigenic stimulation (as opposed to cell mediated immunity).
hyaline membrane disease (respiratory distress syndrome): A disease affecting premature infants who lack pulmonary surfactant. It is characterized by collapse of the alveoli (atelectasis) and pulmonary edema.
hydrocortisone (cortisol): The principal corticosteroid hormone secreted by the adrenal cortex, with glucocorticoid action.
hydrophilic: Having an affinity for water.
hydrophobic: Denoting a substance that repels and that is repelled by water.
hypercapnia: Excessive concentration of carbon dioxide in the blood.
hyperglycemia: An abnormally increased concentration of glucose in the blood.
hyperplasia: An increase in organ size due to an increase in cell numbers as a result of mitotic cell division (in contrast to hypertrophy).
hypersensitivity: abnormal immune response that may be immediate (due to antibodies of the IgE class) or delayed (due to cell-mediated immunity).
hypertension: Elevated or excessive blood pressure.
hypertonic: Denoting a solution with a greater solute concentration and thus a greater osmotic pressure than plasma.
hypertrophy: Growth of an organ due to an increase in the size of its cells (in contrast to hyperplasia).
hyperventilation: A high rate and depth of breathing that results in a decrease in the blood carbon dioxide concentration to below normal.
hypothalamus: A portion of the forebrain within the diencephalon that lies below the thalamus, where it functions as an autonomic nerve center and regulates the pituitary gland.
hypovolemic shock: A rapid fall in blood pressure as a result of diminished blood volume.
hypoxemia: A low oxygen concentration of the arterial blood.
I
immunization: The process of increasing one's resistance to pathogens.
immunoglobulins: Subclasses of the gamma globulin fraction of plasma proteins that have antibody functions, providing humoral immunity.
inferior vena cava: A large systemic vein that collects blood from the body regions inferior to the level of the heart and returns it to the right atrium.
inguinal: Pertaining to the groin region.
inspiration: The act of breathing air into the alveoli of the lungs; also called inhalation.
insulin: A polypeptide hormone secreted by the beta cells of the pancreatic islets that promotes the cellular uptake of blood glucose and, therefore, lowers the blood glucose concentration. Insulin deficiency results in hyperglycemia and diabetes mellitus (type 2 diabetes). A condition in which the pancreas produces little or no insulin results in type 1 diabetes.
interferons: A group of small proteins that inhibit the multiplication of viruses inside host cells and that also have antitumor properties.
internal: Toward the center, away from the surface of the body.
intervertebral disc: A pad of fibrocartilage located between the bodies of adjacent vertebrae.
intrinsic: Situated within or pertaining to internal origin.
in vitro: Occurring outside the body, in a test tube or other artificial environment.
in vivo: Occurring within the body.
ipsilateral: On the same side (as opposed to contralateral).
ischemia: A rate of blood flow to an organ that is inadequate to supply sufficient oxygen and maintain aerobic respiration in that organ.
isthmus: A narrow neck or portion of tissue connecting two structures.
J
jaundice: A condition characterized by high blood bilirubin levels and staining of the tissues with bilirubin, which imparts a yellow color to the skin and mucous membranes.
jejunum: The middle portion of the small intestine, located between the duodenum and the ileum.
K
ketoacidosis: A type of metabolic acidosis resulting from the excessive production of ketone bodies, as in diabetes mellitus.
Krebs cycle: A cyclic metabolic pathway in the matrix of mitochondria by which the acetic acid part of acetyl coenzyme (CoA) is oxidized and substrates are provided for reactions that are coupled to the formation of adenosine triphosphate (ATP).
L
lacrimal gland: A tear-secreting gland, located on the superior lateral portion of the eyeball underneath the upper eyelid.
lactation: The production and secretion of milk by the mammary glands.
large intestine: The last major portion of the GI tract, consisting of the cecum, colon, rectum, and anal canal.
larynx: The structure located between the pharynx and trachea that houses the vocal cords; commonly called the voice box.
lateral: Pertaining to the side; farther from the midplane.
lateral ventricle: A cavity within the cerebral hemisphere of the brain that is filled with cerebrospinal fluid.
lesion: A wounded or damaged area.
leukocyte: A white blood cell.
ligament: A tough cord or fibrous band of connective tissue that binds bone to bone to strengthen and provide flexibility to a joint. It also may support viscera.
low-density lipoproteins (LDLs): Plasma proteins that transport triglycerides and cholesterol. They are believed to contribute to arteriosclerosis.
lower extremity: A lower appendage, including the hip, thigh, knee, leg, and foot.
lumbar: Pertaining to the region of the loins.
lumen: The space within a tubular structure through which a substance passes.
lymph: A clear, plasma like fluid that flows through lymphatic vessels.
lymphatic system: The lymphatic vessels and lymph nodes.
lymphocyte: A type of white blood cell which usually constitutes about 20% to 25% of the white blood cell count.
M
macrophage: A wandering phagocytic cell.
malignant: Threatening to life; virulent. Of a tumor, cancerous, tending to metastasize.
matrix: The intercellular substance of a tissue.
meatus: A passageway or opening into a structure.
medial: Toward or closer to the midplane of the body.
mediastinum: The partition in the center of the thorax between the two pleural cavities. The heart is situated within.
medulla: The center portion of an organ.
medulla oblongata: A portion of the brain stem located between the spinal cord and the pons.
meninges: A group of three fibrous membranes covering the central nervous system, composed of the dura mater, arachnoid mater, and pia mater.
mesencephalon: The midbrain, which contains the corpora quadrigemina and the cerebral peduncles.
metabolism: The sum total of the chemical changes that occur within a cell.
arteriole: Passes through a capillary network and empties into a venule.
metastasis: The spread of a disease from one organ or body part to another.
midsagittal: A plane that divides the body into equal right and left halves; also called the median plane or midplane.
mitosis: The process of cell division that results in two identical daughter cells containing the same number of chromosomes.
mitral valve: The left atrioventricular heart valve; also called the bicuspid valve.
mucosa: A mucous membrane that lines cavities and tracts the opening to the exterior.
myelin sheath: A sheath surrounding axons formed by successive wrappings of a neuroglial cell membrane.
myocardium: The cardiac muscle layer of the heart.
N
nasopharynx: The first or uppermost chamber of the pharynx, positioned posterior to the nasal cavity and extending down to the soft palate.
necrosis: Cellular death or tissue death due to disease or trauma.
neonatal: The stage of life from birth to the end of 4 weeks.
neoplasm: A new, abnormal growth of tissue, as in a tumor.
nerve: A bundle of nerve fibers outside the central nervous system.
neuron: The structural and functional unit of the nervous system, composed of a cell body, dendrites, and an axon; also called a nerve cell.
nucleus: A spheroid body within a cell that contains the genetic factors of the cell.
nystagmus: Involuntary oscillary movements of the eye.
O
olfactory: Pertaining to the sense of smell.
oncotic pressure: The colloid osmotic pressure of solutions produced by proteins. In plasma, it serves to counterbalance the outward filtration of fluid from capillaries due to hydrostatic pressure.
optic: Pertaining to the eye.
orifice: An opening into a body cavity or tube.
osseous tissue: Bone tissue.
osteomalacia: Softening of bones due to a deficiency of vitamin D and calcium.
osteoporosis: Demineralization of bone, seen most commonly in postmenopausal women and patients who are inactive or paralyzed.
ovary: The female gonad in which ova and certain sexual hormones are produced.
P
palmar: Pertaining to the palm of the hand.
palpation: Examining the body by touching and feeling.
papillae: Small, nipple like projections.
paranasal sinus: An air chamber lined with a mucous membrane that communicates with the nasal cavity.
parathyroids: Small endocrine glands embedded on the posterior surface of the thyroid glands that are concerned with calcium metabolism.
parietal: Pertaining to a wall of an organ or cavity.
parotid gland: One of the paired salivary glands located on the side of the face over the masseter muscle just anterior to the ear and connected to the oral cavity through a salivary duct.
pathogen: Any disease-producing microorganism or substance.
pelvis: A basin like bony structure formed by the sacrum and ossa coxae.
pericardium: A protective serous membrane that surrounds the heart.
periosteum: A fibrous connective tissue covering the outer surface of bone.
peripheral nervous system: The nerves and ganglia of the nervous system that lie outside of the brain and spinal cord; PNS.
peristalsis: Rhythmic contractions of smooth muscle in the walls of various tubular organs by which the contents are forced onward.
peritoneum: The serous membrane that lines the abdominal cavity and covers the abdominal visceral organs.
phalanx (pl. phalanges): A bone of a finger or toe.
pharynx: The organ of the digestive system and respiratory system located at the back of the oral and nasal cavities that extends to the larynx anteriorly and to the esophagus posteriorly; also called the throat.
pineal gland: A small cone-shaped gland located in the roof of the third ventricle.
pituitary gland: A small, pea-shaped endocrine gland situated on the interior surface of the diencephalonic region of the brain consisting of anterior and posterior lobes; also called the hypophysis.
plantar: Pertaining to the sole of the foot.
plasma: The fluid, extracellular portion of circulating blood.
plasma cells: Cells derived from B lymphocytes that produce and secrete large amounts of antibodies. They are responsible for humoral immunity.
platelets: Small fragments of specific bone marrow cells that function in blood coagulation; also called thrombocytes.
plexus: A network of interlaced nerves or vessels.
polyuria: Excretion of an excessively large volume of urine in a given period.
pons: The portion of the brain stem just above the medulla oblongata and anterior to the cerebellum.
posterior: Toward the back; also called dorsal.
prone: Lying face-down.
proximal: Closer to the midplane of the body or to the origin of an appendage; the opposite of distal.
pulmonary: Pertaining to the lungs.
pyrogen: A fever-producing substance.
R
radionuclide scanning: A procedure using an IV radioactive substance that generates a color video image, with areas of intense color representing high tissue activity and areas of less intense color representing low tissue activity; used to study the activity of a tissue or organ (brain, heart, lungs, liver).
ramus: A branch of a bone, artery, or nerve.
renal: Pertaining to the kidney.
respiration: The exchange of gases between the external environment and the cells of an organism.
retina: The principal portion of the internal tunic of the eyeball that contains the photoreceptors.
rotation: The movement of a bone around its own longitudinal axis.
S
sagittal plane: A vertical plane, running parallel to the midsagittal plane, that divides the body into unequal right and left portions.
salivary gland: An accessory digestive gland that secretes saliva into the oral cavity.
septum: A membranous or fleshy wall dividing two cavities.
serum: Blood plasma with the clotting elements removed.
shock: As it relates to the cardiovascular system, this term refers to a rapid, uncontrolled fall in blood pressure, which in some cases becomes irreversible and leads to death.
sinus: A cavity or hollow space within a body organ, such as a bone.
somatic: Pertaining to the nonvisceral parts of the body.
spinal cord: The portion of the central nervous system that extends downward from the brain stem through the vertebral canal.
squamous: Flat or scalelike.
steroid: A lipid, derived from cholesterol, that has three 6-sided carbon rings and one 5-sided carbon ring. These form the steroid hormones of the adrenal cortex and gonads.
Stratified: Arranged in layers, or strata.
subarachnoid space: The space within the meninges, between the arachnoid mater and pia mater, where cerebrospinal fluid flows.
sulcus: A shallow impression or groove.
superficial: Toward or near the surface.
superior: Toward the upper part of a structure or toward the head; also called cephalic.
superior vena cava: A large systemic vein that collects blood from regions of the body superior to the heart and returns it to the right atrium.
systemic: Relating to the entire organism rather than to individual parts.
T
tachycardia: An excessively rapid heart rate, usually in excess of 100 beats per minute (in contrast to bradycardia, in which the heart rate is very slow).
tactile: Pertaining to the sense of touch.
tendon: A band of dense regular connective tissue that attaches muscle to bone.
thorax: The chest.
thrombocyte: A blood platelet.
thrombus: A blood clot produced by the formation of fibrin threads around a platelet plug.
trachea: The airway leading from the larynx to the bronchi composed of cartilaginous rings and a ciliated mucosal lining of the lumen; commonly called the windpipe.
transverse plane: A plane that divides the body into superior and inferior portions; also called a horizontal, or cross-sectional, plane.
trunk: The thorax and abdomen.
U
urea: The chief nitrogenous waste product of protein catabolism in the urine; formed in the liver from amino acids.
ureter: A tube that transports urine from the kidney to the urinary bladder.
urethra: A tube that transports urine from the urinary bladder to the outside of the body.
uterus: A hollow, muscular organ in which a fetus develops. It is located within the female pelvis between the urinary bladder and the rectum; commonly called the womb.
V
vacuole: A small space or cavity within the cytoplasm of a cell.
vasoconstriction: Narrowing of the lumen of blood vessels due to contraction of the smooth muscles in their walls.
vasodilation: Widening of the lumen of blood vessels due to relaxation of the smooth muscles in their walls.
vein: A blood vessel that conveys blood toward the heart.
vena cava: One of two large vessels that return deoxygenated blood to the right atrium of the heart.
ventilation: Breathing; the process of moving air into and out of the lungs.
ventral: Toward the front or facing surface; the opposite of dorsal.
ventricle: A cavity within an organ; especially those cavities in the brain that contain cerebrospinal fluid and those in the heart that contain blood to be pumped from the heart.
venule: A small vessel that carries venous blood from capillaries to a vein.
vertebral canal: The tube-like cavity extending through the vertebral column that contains the spinal cord; also called the spinal canal.
virulent: Pathogenic; able to cause disease.
viscera: The organs within the abdominal or thoracic cavities.
W
white matter: Bundles of myelinated axons located in the central nervous system.
Z
zygote: A fertilized egg cell formed by the union of a sperm cell and an ovum.