|
macula |
small, highly
sensitive located in the center of the retina responsible for near and
fine detail vision |
|
macule |
small area of
skin different in color to the majority of the body, but flush with the
surrounding skin |
|
malignant |
cancerous
tumor or other disease state that has a debilitating, unremitting course |
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medial |
inclining
toward the center or midline of the body; opposite of lateral |
|
mediastinoscopy |
insertion of
a tube into the chest, to view the organs in the mediastinum, or the
area between the lungs (including the heart and its veins and arteries,
the trachea, the esophagus, the bronchi, and lymph nodes). An incision
is made at the base of the neck above the breastbone to insert the tube. |
|
melanocytes |
cells
intermingled with the basal cells in the bottom layer of the epidermis
that produce pigment globules known as melanin |
|
melanoma |
skin cancer
that originates in a melanocyte |
|
melena |
blood in the
stool, typically loosely formed or liquid |
|
meninges |
the three
laminated ultrathin membranes surrounding the brain |
|
meningitis |
inflammation
or infection of the meninges |
|
menopause |
period that
marks the permanent cessation of menstrual activity, usually occurring
between the ages of 40 and 58 |
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|
metastasis |
spread of
disease from one organ or part to another |
|
metastasize |
to spread
from one part of the body to another, as in cancer |
|
metastatic |
pertaining to
metastasis; cancer that has spread to either the lymph nodes (regionally
metastatic) or organs, e.g., lung, liver, adrenal glands, bone, or brain
(distant metastasis) |
|
metatarsals |
five bones
that run from the center of the foot to the beginning of the toes
|
|
metered-dose inhaler (MDI) |
most common
device for administering quick-relief asthma medications, consisting of
a tube-shaped mouthpiece connected to a canister that projects a
measured amount of medication when actuated by the user |
|
mg |
milligram |
|
midline |
invisible
reference line that runs longitudinally and divides any body or object
in half |
|
migraine |
headache
characterized by throbbing, one-sided pain, that may be associated with
nausea, vomiting, and aura (sensory disturbances) |
|
mitral valve |
one-way valve
that allows blood to pass from the left atrium into the left ventricle
and normally prohibits its reentry |
|
mixed incontinence |
stress and
urge incontinence occurring simultaneously |
|
mL |
milliliter |
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motor neuron cells |
cells located
in the spinal cord that give rise to nerves that supply the muscles |
|
MRA (magnetic resonance angiography) |
test in which
an MRI scanner is used to focus on structures within which blood flows,
such as the arteries in the neck, brain, and lungs |
|
MRI (magnetic resonance imaging) |
diagnostic
test that uses electromagnetic energy to produce soft-tissue images of
the central nervous and musculoskeletal systems |
|
multi-infarct dementia |
dementia that
is caused by the cumulative affect of multiple strokes |
|
multiple sclerosis (MS) |
chronic
neurological disorder that affects the central nervous system, i.e., the
brain and spinal cord |
|
muscular dystrophy |
congenital
(hereditary) disorder resulting in muscular weakness and dysfunction
|
|
myasthenia gravis |
disorder
affecting the space between the nerve and the muscle (neuromuscular
junction) that results in transient motor weakness of the face and limbs
|
|
myelin |
outer lipid
(fatty) layer that covers nerves and nervous system pathways in the
brain and spinal cord |
|
myelosuppressive |
therapy that
diminishes white blood cell count |
|
myocardial infarction |
medical
emergency that occurs when a blood clot forms suddenly in a coronary
artery and blocks blood flow to an area of the heart; heart attack |
|
myopathy |
disease of
muscular dysfunction, usually causing weakness and atrophy |
|
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