Glossary Terms M-R (140.0K)

macrophage	A type of phagocytic cell found in the liver, spleen, lungs, bone marrow, and connective tissue. Macrophages play several roles in humoral and cellmediated immunity, including presenting the antigens to the lymphocytes involved in these defenses; also known as monocytes while in the bloodstream. (See page(s) 19)
macula densa	An area of the distal convoluted tubule that touches afferent and efferent arterioles. (See page(s) 34)
macular degeneration	A progressive disease that usually affects people over the age of 50. It occurs when the retina no longer receives an adequate blood supply. (See page(s) 33)
magnetic resonance imaging	A viewing technique that uses a powerful magnetic field to produce an image of internal body structures. (See page(s) 41)
maintenance contract	A contract that specifies when a piece of quipment will be cleaned, checked for worn parts, and repaired. (See page(s) 5)
major histocompatibility complex	A large proteincomplex that plays a role in T cell activation. (See page(s) 29)
malignant	A type of tumor or neoplasm that is invasive and destructive and that tends to metastasize; it is commonly known as cancerous. (See page(s) 29)
malleus	A small bone in the middle ear that is attached to the eardrum; also called the hammer. (See page(s) 39)
malpractice claim	A lawsuit brought by a patient against a physician for errors in diagnosis or treatment. (See page(s) 3)
maltase	An enzyme that digests sugars. (See page(s) 31)
mammary glands	Accessory organs of the female reproductive system that secrete milk after pregnancy. (See page(s) 35)
mammography	X-rayexamination of the breasts. (See page(s) 53)
managed care organization	A health-care business that, throughmergers and buyouts, can deliver health care more cost-effectively. (See page(s) 1)
mandible	A bone that forms the lower portion of the jaw. (See page(s) 25)
manipulation	The systematic movement of a patient’s body parts. (See page(s) 38)
marrow	A substance that is contained in the medullary cavity. In adults, it consists primarily of fat. (See page(s) 25)
massage therapist	An individual who is trained to use pressure, kneading, and stroking to promote muscle and full-body relaxation. (See page(s) 2)
mastoid process	A large bump on each temporal bone just behind each ear. It resembles a nipple, hence the name mastoid. (See page(s) 25)
Material Safety Data Sheet	A form that is required for all hazardous chemicals or other substances used in the laboratory and that contains information about the product’s name, ingredients, chemical characteristics, physical and health hazards, guidelines for safe handling, and procedures to be followed in the event of exposure. (See page(s) 8)
matrix	The basic format of an appointment book, established by blocking off times on the schedule during which the doctor is able to see patients. The material between the cells of connectivetissue. (See page(s) 12,23)
matter	Anything that takes up space and has weight. Liquids, solids, and gases are matter. (See page(s) 23)
maturation phase	The third phase of wound healing, in which scar tissue forms. (See page(s) 42)
maxillae	A bone that forms the upper portion of the jaw. (See page(s) 25)
Mayo stand	A movable stainless steel instrument tray on a stand. (See page(s) 42)
medial	A directional term that describes areas closer to the midline of the body. (See page(s) 23)
Medicaid	A federally funded health cost assistance program for low-income, blind, and disabled patients; families receiving aid to dependent children; foster children; and children with birth defects. (See page(s) 15)
medical asepsis	Measures taken to reduce the number of microorganisms, such as hand washing and wearing examination gloves, that do not necessarily eliminate microorganisms; also called clean technique. (See page(s) 42)
medical practice act	A law that defines the exact duties that physicians and other healthcare personnel may perform. (See page(s) 40)
Medicare	A national health insurance program for Americans aged 65 and older. (See page(s) 15)
Medicare+ Choice Plan	Medicare benefit in which beneficiaries can choose to enroll in one of three major types of plans instead of the Original Medicare Plan. (See page(s) 15)
Medigap	Private insurance that Medicare recipients can purchase to reduce the gap in coverage—the amount they would have to pay from their own pockets after receiving Medicare benefits. (See page(s) 15)
medullary cavity	The canal that runs through the center of the diaphysis. (See page(s) 25)
megakaryocytes	Cells within red blood marrow that give rise to platelets. (See page(s) 28)
meiosis	A type of cell division in which each new cell contains only one member of each chromosome pair. (See page(s) 23)
melanin	A pigment that is deposited throughout the layers of the epidermis. (See page(s) 24)
melanocyte	A cell type within the epidermis that makes the pigment melanin. (See page(s) 24)
melatonin	A hormone that helps to regulate circadian rhythms. (See page(s) 32)
membrane potential	The potential inside a cell relative to the fluid outside the cell. (See page(s) 27)
meninges	Membranes that protect the brain and spinal cord. (See page(s) 27)
meningitis	An inflammation of the meninges. (See page(s) 27)
meniscus	The curve in the air-to-liquid surface of a liquid specimen in a container. (See page(s) 37)
menopause	The termination of the menstrual cycle due to the normal aging of the ovaries. (See page(s) 35)
menses	The clinical term for menstrual flow. (See page(s) 35)
menstral cycle	The female reproductive cycle. It consists of regular changes in the uterine lining that lead to monthly bleeding. (See page(s) 35)
mensuration	The process of measuring. (See page(s) 38)
mesoderm	The primary germ layer that gives rise to connective tissue and some epithelial tissue. (See page(s) 35)
metabolism	The overall chemical functioning of the body, including all body processes that build small molecules into large ones (anabolism) and break down large molecules into small ones (catabolism). (See page(s) 23)
metacarpals	The bones that form the palms of the hand. (See page(s) 25)
metastasis	The transfer of abnormal cells to body sites far removed from the original tumor. (See page(s) 41)
metatarsals	The bones  that form the front of the foot. (See page(s) 25)
microbiology	The study of microorganisms. (See page(s) 46)
microfiche	in rectangular sheets. (See page(s) 5)
microfilm	A roll of film stored on a reel and imprinted with information on a reduced scale to minimize storage space requirements. (See page(s) 5)
microorganism	A simple form of life, commonly made up of a single cell and so small that it can be seen only with a microscope. (See page(s) 19)
micropipette	A small pipette that holds a small, precise volume of fluid; used to collect capillary blood. (See page(s) 48)
microvilli	Structures found in the lining of the small intestine. They greatly increase the surface area of the small intestine so it can absorb many nutrients. (See page(s) 31)
micturition	The  process of urination. (See page(s) 34)
midsagittal	Anatomical term that refers to the plane that runs lengthwise down the midline of the body, dividing it into equal left and right halves. (See page(s) 23)
minerals	Natural,inorganic substances the body needs to help build and maintain body tissues and carry on life functions. (See page(s) 49)
minutes	A report of what happened and what was discussed and decided at a meeting. (See page(s) 12)
mirroring	Restating in your own words what a person is saying. (See page(s) 36)
misdemeanor	A less serious crime such as theft under a certain dollar amount or disturbing the peace. A misdemeanor is punishable by fines or imprisonment. (See page(s) 3)
mitosis	A type of cell division that produces ordinary body, or somatic, cells; each new cell receives a complete set of paired chromosomes. (See page(s) 23)
mitral valve	See bicuspid valve. (See page(s) 28)
mobility aids	Devices that improve one’s ability to move from one place to another; also called mobility assistive devices. (See page(s) 43)
modeling	The process of teaching the patient a new skill by having the patient observe and imitate it. (See page(s) 14)
modem	A device used to transfer information from one computer to another through telephone lines. (See page(s) 6)
modified-block letter style	A letter format similar to full-block style, except that the dateline, complimentary closing, signature block, and notations are aligned and begin at the center of the page or slightly to the right of center. (See page(s) 7)
modified-wave schedule	A scheduling system similar to the wave system, with patients arriving at planned intervals during the hour, allowing time to catch up before the next hour begins. (See page(s) 12)
modifier	One or more two-digit codes assigned to the fivedigit main code to show that some special circumstance applied to the service or procedure that the physician performed. (See page(s) 16)
molars	Back teeth that are flat and are designed to grind food. (See page(s) 31)
mold	Fungi that grow into large, fuzzy, multicelled organisms that produce spores. (See page(s) 46)
molecule	The smallest unit into which an element can be divided and still retain its properties; it is formed when atoms bond together. (See page(s) 23)
money order	A certificate of guaranteed payment, whichmay be purchased from a bank, a post office, or some convenience stores. (See page(s) 18)
monocytes	A large white blood cell with an oval or horseshoe-shaped nucleus that defends the body by phagocytosis; develops into a macrophage when it moves from blood into other tissues. (See page(s) 28)
monosaccharide	A type of carbohydrate that is a simple sugar. (See page(s) 31)
mons pubis	A fatty area that overlies the public bone. (See page(s) 35)
moral values	Values or types of behavior that serve as a basis for ethical conduct and are formed through the influence of the family, culture, or society. (See page(s) 3)
mordant	A substance, such as iodine, that can intensify or deepen the response a specimen  has to a stain. (See page(s) 46)
morphology	The study of the shape or form of objects. (See page(s) 48)
morula	A zygote that has undergone cleavage and results in a ball of cells. (See page(s) 35)
motherboard	The main circuit board of a computer that controls the other components in the system. (See page(s) 6)
motor	Efferent neurons that carry information from the central nervous system to the effectors. (See page(s) 27)
mucocutaneous exposure	Exposure to a pathogen through mucous membranes. (See page(s) 21)
mucosa	The innermost  layer of the wall of the alimentary canal. (See page(s) 31)
mucous cells	Cells that are found in the salivary glands and the lining of the stomach and that secrete mucous. (See page(s) 31)
MUGA scan	A radiologic procedure that evaluates the condition of the heart’s myocardium; it involves injection of radioisotopes that concentrate in the myocardium, followed by the use of a gamma camera to measure ventricular contractions to evaluate the patient’s heart wall. (See page(s) 53)
multimedia	More than one medium, such as in graphics, sound, and text used to convey information. (See page(s) 6)
multitasking	Running two or more computer software programs  simultaneously. (See page(s) 6)
multi-unit smooth muscle	A type of smooth muscle that is found in the iris of the eye and in the walls of blood vessels. (See page(s) 26)
murmur	An abnormal heart sound heard when the ventricles contract and blood leaks back into the atria. (See page(s) 28)
muscle tissue	A tissue type that is specialized to shorten and elongate. (See page(s) 23)
muscle fatigue	A condition caused by a buildup of lactic acid. (See page(s) 26)
muscle fiber	Muscle cells that are called fibers because of their long lengths. (See page(s) 26)
muscular dystrophy	A group of inherited disorders characterized by a loss of muscle tissue and by muscle weakness. (See page(s) 26)
mutation	An error that sometimes occurs when DNA is duplicated. When it occurs, it is passed to descendent cells and may or may not affect them in harmful Aways. (See page(s) 23)
myasthenia gravis	An autoimmune disorder that is characterized by muscle weakness. (See page(s) 26)
myelin	A fatty substance that insulates the axon and allows it to send nerve impulses quickly. (See page(s) 27)
myelography	An x-ray visualization of the spinal cord after the injection of a radioactive contrast medium or air into the spinal subarachnoid space (between the second and innermost of three membranes that cover the spinal cord). This test can reveal tumors, cysts, spinal stenosis, or herniated disks. (See page(s) 41)
myocardial infarction	A heart attack that occurs when the blood flow to the heart is reduced as a result of blockage in the coronary arteries or their branches. (See page(s) 28)
myocardium	The middle and thickest layer of the heart. It is made primarily of cardiac muscle. (See page(s) 28)
myofibrils	Long structures that fill the sarcoplasm of a muscle fiber. (See page(s) 26)
myoglobin	A pigment contained in muscle cells that stores extra oxygen. (See page(s) 26)
myoglobinuria	The presence of myoglobin in the urine; can be caused by injured or damaged muscle tissue. (See page(s) 47)
myometrium	The middle, thick muscular layer of the uterus. (See page(s) 35)
myopia	A condition that occurs when light entering the eye is focused in front of the retina; commonly called nearsightedness. (See page(s) 33)
myxedema	A severe type of hypothyroidism that is most common in women over the age of 50. (See page(s) 32)
nail bed	The layer beneath each nail. (See page(s) 24)
narcotic	A popular term for an opioid and term of choice in government agencies; see opioid. (See page(s) 50)
nasal	Relating to the nose. The nasal bones fuse to form the bridge of the nose. (See page(s) 25)
nasal conchae	Structures that extend from the lateral walls of the nasal cavity. (See page(s) 30)
nasal mucosa	The lining of the nose.
nasal septum	A structure that divides the nasal cavity into a left and right portion. (See page(s) 30)
nasolacrimal duct	A structure located on the medial aspect of each eyeball. These ducts drain tears into the nose. (See page(s) 33)
nasopharynx	The portion of the pharynx behind the nasal cavity. (See page(s) 31)
natural killer	Non-B and non-T lymphocytes. NK cells kill cancer cellsand virus-infected cells without previous exposure to the antigen. (See page(s) 29)
needle biopsy	A procedure in which a needle and syringe are used to aspirate (withdraw by suction) fluid or tissue cells. (See page(s) 42)
negligence	A medical professional’s failure to perform an essential action or performance of an improper action that directly results in the harm of a patient. (See page(s) 3)
negotiable	Legally transferable from one person to another. (See page(s) 18)
neonatal period	The first four weeks of the postnatal period of an offspring. (See page(s) 35)
neonate	An infant during the first four weeks of life. (See page(s) 35)
nephrologist	A specialist who studies, diagnoses, and manages diseases of the kidney. (See page(s) 2)
nephrons	Microscopic structures in the kidneys that filter blood and form urine. (See page(s) 34)
nerve fiber	A structure that extends from the cell body. It consists of two types: axons and dendrites. (See page(s) 27)
nerve impulse	Electrochemical messages transmitted from neurons to other neurons and effectors. (See page(s) 27)
nervous tissue	A tissue type located in the brain, spinal cord, and peripheral nerves. (See page(s) 23)
net earnings	Takehome pay, calculated by subtracting total deductions from grossearnings. (See page(s) 18)
network	A system that links several computers together. (See page(s) 6)
networking	Making contacts with relatives, friends, and acquaintances that may have information about how to find a job in your field. (See page(s) 54)
neuralgia	A medical condition characterized by severe pain along the distribution of a nerve. (See page(s) 27)
neuroglial cell	Non-neuronal type of nervous tissue that is smaller and more abundant than neurons. Neuroglial cells support neurons. (See page(s) 27)
neurologist	A specialist who diagnoses and treats disorders and diseases of the nervous system,including the brain, spinal cord, and nerves. (See page(s) 2)
neuron	A nerve cell; it carries nerve impulses between the brain or spinal cord and other parts of the body. (See page(s) 23)
neurotransmitter	A chemical within the vesicles of the synaptic knob that is released into the postsynaptic structures when a nerve impulse reaches the synaptic knob. (See page(s) 27)
neutrophil	A type of granular leukocyte that aids in phagocytosis by attacking bacterial invaders; also responsible for the release of pyrogens. (See page(s) 28)
new patient	Patient that, for CPT reporting purposes, has not received professional services from the physician within the past three years. (See page(s) 16)
nocturia	Excessive nighttime urination. (See page(s) 47)
noncompliant	The term used to describe a patient who does not follow the medical advice given. (See page(s) 9)
noninvasive	Referring to procedures that do not require inserting devices, breaking the skin, or monitoring to the degree needed with invasive procedures. (See page(s) 53)
nonsteroidal hormone	A type of hormone made of amino acids and proteins. (See page(s) 32)
norepinephrine	A neurotransmitter released by sympathetic neurons onto organs and glands for fight-or-flight (stressful) situations. (See page(s) 26)
normal flora	Beneficial bacteria found in the body that create a barrier against pathogens by producing substances that may harm invaders and using up the resources pathogens need to live. (See page(s) 19)
no-show	A patient who does not call to cancel and does not come to an appointment. (See page(s) 12)
nosocomial infection	An infection contracted in a hospital. (See page(s) 20)
Notice of Privacy Practices	A document that informs patients of their rights as outlined under HIPAA. (See page(s) 3)
nuclear medicine	The use of radionuclides, or radioisotopes(radioactive elements or their compounds), to evaluate the bone,brain, lungs, kidneys, liver, pancreas,thyroid, and spleen; also known as radionuclide imaging. (See page(s) 53)
nucleases	Pancreatic enzymes that digest nucleic acids. (See page(s) 31)
nucleus	The control center of a cell; contains the chromosomes that direct cellularprocesses. (See page(s) 23)
numeric filing system	A filing system that organizes files by numbers instead of names. Each patient is assigned a number in the order in which she joins the practice. (See page(s) 10)
O and P specimen	An ova and parasites specimen, or a stool sample, that is examined for the presence of certain forms of protozoans or parasites, including their eggs (ova). (See page(s) 46)
objective	Pertaining to data that is readily apparent and measurable, such as vital signs, test results, or physical examination findings. (See page(s) 9)
objectives	The set of magnifying lenses contained in the nosepiece of a compound microscope. (See page(s) 45)
occipital	Relating to the back of the head. The occipital bone forms the back of the skull. (See page(s) 25)
occult blood	Blood contained in some other substance, not visible to the naked eye. (See page(s) 22)
ocular	An eyepiece of a microscope. (See page(s) 45)
oil-immersion objective	A microscope objective that is designed to be lowered into a drop of immersion oil placed directly above the prepared specimen under examination, eliminating the air space between the microscope slide and the objective and producing a much sharper, brighter image. (See page(s) 45)
ointment	A form of topical drug; also known as a salve. (See page(s) 51)
Older Americans Act of 1965	A U.S. law that guarantees certain benefits to elderly citizens, including health care, retirement income, and protection against abuse. (See page(s) 13)
olfactory	Relating to the sense of smell. (See page(s) 33)
oliguria	Insufficient production (or volume) of urine. (See page(s) 47)
oncologist	A specialist who identifies tumors and treats patients who have cancer. (See page(s) 2)
onychectomy	The removal of a fingernail or toenail. (See page(s) 42)
oocyte	The immature egg. (See page(s) 35)
oogenesis	The process of egg cell formation. (See page(s) 35)
open-book account	An account that is open to charges made occasionally as needed. (See page(s) 17)
open hours scheduling	A system of scheduling in which patients arrive at the doctor’s office at their convenience and are seen on a first-come, firstserved basis. (See page(s) 12)
open posture	A position that conveys a feeling of receptiveness and friendliness; facing another person with arms comfortably at the sides or in the lap. (See page(s) 4)
ophthalmologist	A medical doctor who is an eye specialist. (See page(s) 39)
ophthalmoscope	A hand-held instrument with a light; used to view inner eye structures. (See page(s) 41)
opioid	A natural or synthetic drug that produces opium-like effects. (See page(s) 50)
optic chiasm	A structure located at the base of the brain where parts of the optic nerves cross. It carries visual information to the brain. (See page(s) 32)
optical microscope	A microscope that uses light, concentrated through a condenser and focused through the object being examined, to project an image. (See page(s) 45)
opportunistic infection	Infection by microorganisms that can cause disease only when a host’s resistance is low. (See page(s) 19)
optometrist	A trained and licensed vision specialist who is not a physician. (See page(s) 39)
orbicularis oculi	The muscle in the eyelid responsible for blinking. (See page(s) 33)
orbit	The eye socket, which forms a protective shell around the eye. (See page(s) 39)
organ	Structure formed by the organization of two or more different tissue types that carries out specific functions. (See page(s) 23)
organelle	A structure within a cell that performs a specific function. (See page(s) 23)
organic	Pertaining to matter that contains carbon and hydrogen. (See page(s) 23)
organism	A whole living being that is formed from organ systems. (See page(s) 23)
organ system	A system that consists of organs that join together to carry out vital functions. (See page(s) 23)
origin	An attachment site of a skeletal muscle that does not move when a muscle contracts. (See page(s) 26)
Original Medicare Plan	The Medicare feefor- service plan that allows the beneficiary to choose any licensed physician certified by Medicare. (See page(s) 15)
oropharynx	The portion of the pharynx behind the oral cavity. (See page(s) 31)
orthopedist	A specialist who diagnoses and treats diseases and disorders of the muscles and bones. (See page(s) 2)
OSHA	A set of regulations designed to save lives, prevent injuries,and protect the health of workers in the United States. (See page(s) 1)
osmosis	The diffusion of water across a semipermeable membrane such as a cell membrane. (See page(s) 23)
ossification	The process of bone growth. (See page(s) 25)
osteoblast	Boneforming cells that turn membrane into bone. They use excess blood calcium to build new bone. (See page(s) 25)
osteoclast	Bonedissolving cells. When bone is dissolved, calcium is released into the bloodstream. (See page(s) 25)
osteocyte	A cell of osseous tissue; also called a bone cell. (See page(s) 25)
osteon	Elongated cylinders that run up and down the long axis of bone. (See page(s) 25)
osteopathic manipulative medicine	A system of handson techniques that help relieve pain, restore motion, support the body’s natural functions, and influence the body’s structure. Osteopathic physicians study OMM in addition to medical courses. (See page(s) 2)
osteoporosis	An endocrine and metabolic disorder of the musculoskeletal system, more common in women than in men, characterized by hunched-over posture. (See page(s) 40)
osteosarcoma	A type of bone cancer that originates from osteoblasts, the cells that make bony tissue. (See page(s) 25)
otologist	A medical doctor who specializes in the health of the ear. (See page(s) 39)
otorhinolaryngologist	A specialist who diagnoses and treats diseases of the ear, nose, and throat. (See page(s) 2)
out guide	A marker made of stiff material and used as a placeholder when a file is taken out of a filing system. (See page(s) 10)
oval window	The beginning of the inner ear. (See page(s) 33)
overbooking	Scheduling appointments for more patients than can reasonably be seen in the time allowed. (See page(s) 12)
ovulation	The process by which the ovaries release one ovum (egg) approximately every 28 days. (See page(s) 35)
oxygen debt	A condition that develops when skeletal muscles are used strenuously for a minute or two. (See page(s) 26)
oxyhemoglobin	Hemoglobin that is bound to oxygen. It is bright red in color. (See page(s) 28)
oxytocin OT	A hormone that causes contraction of the uterus during childbirth and the ejection of milk from mammary glands during breast-feeding. (See page(s) 32)
packed red blood cells	Red blood cells that collect at the bottom of a centrifuged blood sample. (See page(s) 48)
palate	The roof of the mouth. (See page(s) 31)
palatine	Bones that form the anterior potion of the roof of the mouth and the palate.
palatine tonsils	Two masses of lymphatic tissue located at the back of the throat. (See page(s) 31)
palpation	A type of touch used by health-care providers to determine characteristics such as texture, temperature, shape, and the presence of movement. (See page(s) 38)
palpatory method	Systolic blood pressure measured by using the sense of touch. This measurement provides a necessary preliminary approximation of the systolic blood pressure to ensure an adequate level of inflation when the actual auscultatory measurement is made. (See page(s) 37)
palpitations	Unusually rapid, strong, or irregular pulsations of the heart. (See page(s) 44)
pancreatic amylase	An enzyme that digests carbohydrates. (See page(s) 31)
pancreatic lipase	An enzyme that digests lipids. (See page(s) 31)
panel	Tests frequently ordered together that are organ or disease oriented. (See page(s) 16)
papillae	The “bumps” of the tongue in which the taste buds are found. (See page(s) 33)
paranasal sinuses	Air-filled spaces within skull bones that open into the nasal cavity. (See page(s) 30)
parasite	An organism that lives on or in another organism and relies on it for nourishment or some other advantage to the detriment of the host organism. (See page(s) 46)
parasympathetic	A division of the autonomic nervous system that prepares the body for rest and digestion. (See page(s) 27)
parathyroid hormone	A hormone that helps regulate calcium levels in the bloodstream. (See page(s) 35)
parenteral nutrition	Nutrition obtained when specially prepared nutrients are injected directly into patients’ veins rather than taken by mouth. (See page(s) 49)
paresthesias	Abnormal sensations ranging from burning to tingling. (See page(s) 27)
parietal	Bones that form most of the top and sides of the skull. (See page(s) 25)
parietal cells	Stomach cells that secrete hydrochloric acid, which is necessary to convert pepsinogen to pepsin Parietal cells also secrete intrinsic factor,which is necessary for vitamin B12 absorption. (See page(s) 31)
parietal pericardium	The layer on top of the visceral pericardium. (See page(s) 28)
parotid glands	The largest of the salivary glands. The parotid glands are located beneath the skin just in front of the ears. (See page(s) 31)
participating physicians	Physicians who enroll in managed care plans. They have contracts with MCOs that stipulate their fees. (See page(s) 15)
passive listening	Hearing what a person has to say without responding in any way; contrast with active listening. (See page(s) 4)
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