calcification - Process by which organic tissue becomes hardened by a deposit of calcium salts within its substance.
calcium crystal- Mineral components that facilitate the healing and repair process of bones.
calor - The heat aspect of the inflammatory phase.
caloric testing - A method of testing the integrity of the inner ear (balance) apparatus by injecting warm or cold water into the ear and by recording the duration of the nystagmus this produces.
calvaria - The cranium, or more specifically, the skull cap.ﾠ The roof of the skull.
canal, canaliculus - Narrow, cylindrical passage or channel. A general term to describe a variety of small channels.
cancellous bone - Bone substance made of thin intersecting lamellae, usually found internal to compact bone.
capillary - A minute blood vessel which connects an arteriole and venule, forming a network in nearly all parts of the body and effecting a transition from arterial to venous blood flow.
capsula or capsule - General term for a cartilaginous, fibrous, or membranous structure that envelops another structure, organ, or part. The articular capsule envelops the joint. It consists of two parts: a fibrous capsule and a synovial membrane (capsule). When the term joint capsule is used, it is usually the fibrous part that is meant. The synovial membrane is a vascular connective tissue membrane that lines the entire joint cavity, although it does not cover the articular cartilage. The synovial membrane produces synovial fluid that lubricates the joint. It is the synovial membrane (capsule) in the joint that becomes inflamed with arthritis.
capsular ligaments - Ligaments with saclike envelopes, which enclose the cavity of a synovial joint by attaching to the circumference of the articular end of each involved bone. Also called joint or synovial capsule.
carcinogen - Any substance which produces cancer.
carcinoma - A malignant new growth (cancer) that tends to infiltrate surrounding tissue and give rise to metastases.
carotid arteries - Arteries carrying blood to the head. The common carotid artery originates from the brachiocephalic trunk and the aortic arch, goes through the neck, and distributes through its branches, the internal and external carotid arteries. The internal carotid arteriesﾒ branches distribute into the middle ear, brain, pituitary gland, orbit, and choroid plexus. The external carotid artery via its branches distributes into the neck, face, and skull and is called the facial artery.
carotid system - A system of blood circulation to certain parts of the brain deriving from the internal carotid arteries.
cartilage - Specialized type of connective tissue that supports and aids in movement at joints.
cartilaginous joint - Classified as to structure, this joint has no joint cavity and is joined by hyaline cartilage or a fibrocartilaginous disk. As to movement, they are usually amphiarthroses (Gr. amphi, both sides + arthroses, joint), allowing little or none. The two types are the synchondroses (Gr. synchrondosis, ﾓa growing into one cartilageﾔ) that permits growth and the symphyses (Gr. symphusis, growing together, natural junction), which have shock-absorbing intervertebral discs.
cauda - General term for a structure resembling such a continuation.
caudad - Directed toward the tail.
cauda equina - In the human spine, it is made up of a bundle of neural tissue, connective tissue, pia mater, and neuron cells, and starts below the end of the spinal cord, beyond the L2 vertebra in the adult vertebral canal. It derives from the useless remnant of the spinal cord that was in the tail of the embryo. Where it begins, it is made up of remainders of neural tissue, connective tissue, pia mater, and neuroglial tissue. At its lower end, it becomes a thin, fibrous strand descending among the nerve rootlets of the cauda equina. It leaves the lower end of the dural sac, passes through the sacral hiatus, blends with the upper end of the anococcygeal ligament, and ends by inserting into the back of the coccyx. Known as the filum terminale, this tail or tail-like appendage has no functional use.
caudal - Suggesting a position more toward the cauda or tail rather than some specified point of reference. In human anatomy, it means the same as inferior.
caudate nucleus - An elongated, arched mass of gray matter that is adjacent to the lateral ventricle of the brain throughout its entire extent and consists of a head, body, and tail. The caudate nucleus, lentiform nucleus, and putamen compose the corpus striatum, which is located in front of the thalamus.
cavitation - A physio-chemical process resulting in the production of microscopic explosions of gas within the brain following rapid acceleration of the brain inside the skull.
cellular pleomorphism - Assumption by cells of various distinct forms. Also, the property of crystalizing in two or more forms.
central cord lesion syndrome - A condition usually caused by forceful hyperextension of the neck, especially in old people who have osteoarthritis or spinal canal stenosis. It is characterized by weakness or paralysis of the upper extremities, and to a lesser degree, the lower extremities. The patient may have urinary retention and inability to control defecation. However, some sensation of the sphincter may be preserved. The younger the person is, the better the prognosis. Usually, the leg, the bowel and the bladder function return first.
central dysarthria - Impairment of ability to enunciate words, characterized by an omission, addition, or transposition of syllables.
central fissure (Rolandic fissure) - A fissure is a deep fold in the cerebral cortex which involves the entire thickness of the brain wall. The central fissure is the deep fold between the frontal and parietal lobes.
central nervous system - The brain and spinal cord.
centrolateral - See paracentral. Synonyms: paracentral, paramedian.
cephalad - Directed toward the head.
cephalic - Pertaining to the head.
cerebellar fits - Episodes of decerebrate rigidity usually associated with large midline cerebellar masses.
cerebellum - A structure lying in between the undersurface of the occipital lobe and the brain stem, largely concerned with the regulation and control of the muscular tone, coordination, movement, posture, and gait.
cerebral angiogram - A procedure of visualization of blood vessels of the brain, using x-rays taken after injection of radiopaque material into the arterial blood stream.
cerebral anoxia - A condition in which the cells of the brain do not have (or cannot utilize) sufficient oxygen to perform normal functions.
cerebral atrophy - A wasting away or diminution in the size of cells or tissue structures of the brain.
cerebral blood flow - The rate of blood flow through the brain, which may be measured by various techniques and determined for various regions of the brain.
cerebral cortex - The thin surface layer of gray matter (nerve cell bodies) that forms the outer surface of the cerebrum.
cerebral edema - Any extracerebral condition that increases cerebral blood volume, such as a low blood content (hypoxia) and a high carbon dioxide content (hypercapnia).
cerebral embolism - A sudden blocking or obstruction of an artery or vein by a clot which has been brought to the position of blockage by the current of blood flow.
cerebral hemisphere - The large structure representing either half of the cerebrum.
cerebral hemorrhage - Bleeding of a blood vessel within the cerebrum.
cerebral infarct - An area of coagulation necrosis in a cerebral vessel which obstructs circulation and results in pathological changes in the area deprived of blood supply.
cerebral lateralization - The concept that left and right sides of the brain have different but overlapping and integrated functions determining certain personality traits, creativity, and other qualities.
cerebral palsy - Impaired muscular power and coordination as a result of brain damage, usually occurring at, before, or shortly after birth.
cerebral vascular accident (CVA or stroke) - An embolism, infarct, or hemorrhage of a cerebral vessel.
cerebral vascular insufficiency - Lack of a sufficient supply of blood (which can be due to many factors) for the brain to perform its normal functions.
cerebrospinal fluid - The fluid contained within the cerebral ventricles, subarachnoid sinus, and the central canal of the spinal cord. It acts as a water cushion to protect the brain and spinal cord from shock.
cerebrum - The paired cerebral hemispheres.
cervical - Pertaining to the neck.
cervical area - The section of the spine that allows movement of the head and permits the nerves of the spinal cord to pass through it, going from the head to the rest of the body.
cervical disc disease - Continuation of the chemical process of aging starting within the nucleus pulposus that results in annular tearing, acute disc herniation, or diffuse cervical spondylosis. A natural process, often asymptomatic, it proceeds at different rates in different people.
cervical spondylosis - This degenerative joint disease affects the cervical vertebrae, their intervertebral discs, and their surrounding ligaments and connective tissue. It is usually related to osteoarthritis. Sometimes it comes with pain or paresthesia radiating down the arms, as a result of pressure on the nerve roots.
cervical vertebrae - Seven small neck bones between the skull and thoracic vertebrae that support the head and allow it to move.
cervicothoracic junction - Where the spine of the neck and the chest meet.
chance-type fracture - The so-called seat belt injury, a horizontal avulsion injury of the intervertebral body as a result of flexion about an axis, in front of the anterior longitudinal ligament. The entire vertebra is pulled apart by a strong tensile force.
chiasm - A crossing or decussation of parts. The optic chiasm refers to the crossing of fibers of the optic nerve, forming the optic tract, that lies on the ventra surface of the brain.
chondrification - The formation of cartilage; transformation into cartilage.
chondroblast - A specialized cartilage connective tissue cell.
chondrocyte - In the cartilage matrix, there is a small pit or hollow cavity called a lacuna. A chondrocyte is a mature cartilage cell firmly fixed there.
chondroid - Resembling cartilage.
chondromalacia facetae - Softening of the articular cartilage, mostly in the knee.
chordoma - A malignant tumor which arises from the embryonic remains of the notochord.
chorea - Involuntary, jerking, irregular writhing movements usually of limbs, often indicative of CNS disease.
choreiform movements - Movements that occur in the various forms of chorea which consist of rapid, highly complex, jerky movements that appear to be well coordinated but are performed involuntary and go on continuously in a variety of expressions.
choreoathetotic movements - Movements of both a choreic and athetoid nature. Athetosis is marked by ceaseless occurrence of slow, sinuous, writhing movements that are involuntary and may be particularly severe in the hands.
choroid plexus - A highly vascularized fold of the pia matter in the third, fourth, and lateral ventricles that secretes the cerebrospinal fluid.
chromosome - DNA material that carries the genetic information or basic plan for the development of the fetus. Each sperm cell and each egg contain a single set of twenty-three chromosomes.
chronic - Long-standing (months or years) but not necessarily irreversible. Symptoms may be mild or severe.
cicatrix - The new tissue formed in the healing of a wound.
cingulate gyrus - A convolution (gyrus) which is arch-shaped and closely adjacent to the surface of the corpus collosum, from which is it separated by the callosal sulcus.
Circle of Willis - A circular system of cerebral arteries formed principally by the internal carotid, the anterior and posterior cerebral arteries, and the posterior communicating arteries.
cisterna magna - Enlarged subarachnoid space between the undersurface of the cerebellum and the posterior surface of the medulla oblongata and continuous with the subarachnoid space. It can be tapped by means of a needle inserted through the atlanto-occipital membrane (cisternal puncture). Also called cerebromedullary cistern.
cisternography - Radiographic visualization of the basal cisterns of the brain after injection of a contrast substance.
clinical stability - The spineﾒs ability, under physiologic loads, to confine patterns of displacement in order not to damage or irritate the spinal cord, cauda equina, or nerve roots and, in addition, to prevent disabling deformity or pain because of structural changes.
clonus - Alternate muscular contraction and relaxation in rapid succession.
coccygeal ligament - Very strong triangular or inverted Y-shaped band that covers the anterior and superior portions of the hip joint. It arises by its apex from the anterior inferior iliac spine and is inserted by its base into the intertrochanteric line of the femur.
coccygeal plexus - Coccygeal nerve plus communications from nerves S4 and S5.
coccyx - At the end of the vertebral column and below the sacrum, three to five vertebrae are called the coccyx, commonly known as the tailbone.
cognitive - Having to do with functions of knowing, including reasoning ability, memory retrieval, and perception.
cognitive/intellectual development - Refers to the process wherein an individual acquires both the intellectual and executive functions, and manner of reasoning which characterize the species. In humans, this process moves from a state of essentially no capacity to reason (even at the simple level of understanding of cause and effect) to the eventual acquisition of the ability to think and reason abstractly.
cogwheeling - A phenomenon that occurs among patients with Parkinson's disease in which a muscle, when passively stretched, develops a degree of hypertonicity and resistance, occurring in the form of irregular jerkiness of movement.
collagen - The protein substance of white (collagenous) fibers of connective tissue.
collateral sprouting - Intact axons located near damaged areas may sprout to reestablish connections with, and in place of damaged areas; cannot be assured that the new connections function exactly as their damaged neighbors did.
colloid cyst - A cyst that occurs particularly in the third ventricle and contains jelly-like material.
coma - A state of unconsciousness wherein the person is incapable of responding to internal or external stimuli.
comminuted fracture - A fracture that is often the result of a combination of external force on the axis and of flexion force from the side. Usually, a fracture has torn away at the crosswise ligament (avulsion fracture) plus one-sided frontal and posterior arch fractures have occurred. Comminuted fractures are the least likely to unite, and therefore, function is affected afterward.
common peroneal nerve - Sensory and motor nerve that originates in the sciatic nerve in the lower part of the thigh. Its branches supply the short head of the biceps femoris muscle while it is still incorporated with the sciatic nerve. It gives off the lateral sural cutaneous nerve and peroneal communicating branch as it descends into the popliteal fossa. It supplies the knee and superior ribiofibular joints and tibialis anterior muscle, and divides into superficial and deep peroneal nerves.
communicating hydrocephalus - Hydrocephalus is a condition in which there is an abnormal accumulation of cerebral spinal fluid within the skull. Communicating hydrocephalus is a condition in which there is no obstruction in the ventricular system and cerebrospinal fluid is able to pass out of the brain but is not re-absorbed.
compensation neurosis - An outdated term sometimes (erroneously) confused with traumatic neurosis and referring to a set of ill-defined symptoms that arise in the context of a potential for benefit deriving from an accident.
compression - Literally, squeezing together; used to indicate the physical change the body undergoes when an external force decreases its volume and increases its density. In embryology, it refers to the abbreviation or curtailing of some stage or stages during development.
compressive extension lesion - Occurs when the skull is knocked backward and downward against the backbone. A man on a construction job who nearly gets his block knocked off by a ﾓheadache ballﾔ that is dropped on him will have this type of injury.
compressive flexion lesion - A kind of trauma that often results from head-on collisions and falls from roofs.
compromise - Word used by surgeons when what they find during a physical examination indicates pressure on the nerve root. Often it is due to pathologically changed spaces in the vertebral canal, especially a herniated disc or degenerative bony overgrowth.
computerized axial tomography (CAT scan) - An x-ray technique which photographs serial "slices" of tissue, producing detailed scanning.
concave - Having a rounded, somewhat depressed surface like the hollowed, inner surface of a piece of a sphere.
concussion - A reversible paralysis of nervous functions following brain trauma, usually involving a transient loss of consciousness and/or a transient state of confusion.
condyle - Knuckle-shaped projection on a bone, either knoblike or convex.
confabulation - The involuntary production of a false or pseudomemory to cover a fundamental defect of memory; arises from brain tissue impairment.
connnective tissue - Supportive and connective tissue consisting of fibers, ground substance, cells, and some extracellular fluid; the most abundant type of tissue.
confusion - A state wherein thinking lacks clarity, direction, and the ability to attend and concentrate.
congenital lesions - Lesions present at or dating from birth.
constructional dyspraxia - Impaired ability to deal with spatial relationships either in a two- or three-dimensional framework. This symptom is commonly manifested by impaired ability to copy simple shapes, such as a cross.
contact - When disc material and the neural structures have no intervening epidural fat between them or noticeable displacement or disfiguration of the nerve roots or thecal sac, the imaging report will refer to the relationship using this term. Synonym: abut.
contained - This word has slightly different meanings according the author involved. Basically, it directs attention to the outer anatomic boundary confining the disc herniation. However, different posterior boundaries may be decided upon, according to the author (either the outer annular layers or the posterior longitudinal ligament or both). Some use contained to show a herniated disc has ruptured through the outer annular layer but is confined by the posterior longitudinal ligament (subligamentous). Others suggest, and it seems more acceptable, for it to be confined by the outer border of the annulus (subannular).
contained disc - In a discogram, when the dye injected into the disc remains inside the annulus fibrosus of the suspected disc, as shown on X-ray, the disc is then referred to as a ﾓcontained disc.ﾔ If the dye goes outside the annulus fibrosus, then the fissure has gone all the way through the outer wall of the disc.
contractility - Capacity for becoming short in response to a suitable stimulus.
contraction - The shrinkage and spontaneous closing that takes place in open skin wounds. Contraction pulls normal tissue into the open area to achieve coverage.
contracture - When a scar shrinks, the loss of tissue mobility is known as contracture. The term is also used when fixed high resistance is noted as a muscle is stretched, passively, caused either by fibrosis of the tissues supporting the muscles or joints or disorders of the fibers of the muscle.
contralateral - Pertaining to opposite sides of the body.
contrecoup - Phenomenon employed to explain the location of brain damage which occurs on the side or pole of the brain opposite the impact.
contusions - Microscopic or visible hemorrhages into tissue; a bruise. Following head injury, contusions occur more often in frontal and temporal poles of the brain.
conus terminalis - The cone-shaped lower-most end of the spinal cord, at the level of the upper lumbar vertebrae where it tapers very abruptly, and from which a slender fibrous strand (the cauda) descends among the nerve rootlets; called also terminal cone of the spinal cord.
conversion disorder (conversion hysteria) - A psychiatric condition in which aberrant bodily functioning arises from psychologic conflict or need. Coded 300.11.
coronal view - Indicates a plane as seen from the front, if you cut across the head from one ear to the other (dividing the front from the back). Cuts made parallel to that would be called coronal cuts. Coronal means, also, pertaining to the crown of the head. Coronal view is of a section passing through the body at right angles to the median plane (midsagittal). You can remember this by visualizing a king from the front, with the downward cuts from ear to ear not disturbing, from your viewpoint, the outline of his crown.
coronalis - Coronal; denotes a structure situated in the direction of the coronal suture.
corpectomy - Surgical removal of a vertebral body of the spine.
cortex - The outer layer of an organ or part.
cortical - Pertaining to the outer layer of an organ or the body structure, as distinguished from the internal substance.
costa - Rib.
costo-central ligaments - Ligaments (both capsular and interarticular) that join the ribsﾒ heads to the vertebral bodies.
costo-transverse ligaments - Ligaments (anterior, middle, posterior, and capsular) that link the necks and tubercles (small elevations) of the ribs to the transverse processes.
costotransversectomy - The surgical removal of the portion of the rib (costa) that is attached to the transverse process, which is also removed.
costovertebrae - The vertebrae in the spine that correspond to the ribs.
cranial nerves - Twelve very important nerves which originate in the midbrain and which innervate structures in the head, neck and some body organs.
cremasteric cutaneous reflexes - Stimulation of the skin on the front and inner side of the thigh retracts the testis on the same side. The presence of this reflex reflects integrity of the first lumbar nerve segment of the spinal canal or its root; absence indicates damage of the first lumbar nerve segment or its root or lesion of the corticospinal tract.
cruciform ligament of atlantis - Ligament in the form of a cross, of which the transverse ligament of the atlas forms the horizontal bar, and the longitudinal fascicles, the vertical bar of the cross.
INDEX: To go directly to a section, click on a letter below.
