medical terminology

[mohammad qasaimeh]

this topic will be specified for medical terminology in general

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[mohammad qasaimeh]

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the Pacemaker

Pacemaker: A system that sends electrical impulses to the heart in order to set the heart rhythm. The pacemaker can be the normal "natural" pacemaker of the heart or it can be an electronic device.
The natural pacemaker of the heart is the sinus node, one of the major elements in the cardiac conduction system, the system that controls the heart rate. This stunningly designed system generates electrical impulses and conducts them throughout the muscle of the heart, stimulating the heart to contract and pump blood.
The sinus node consists of a cluster of cells that are situated in the upper part of the wall of the right atrium (the right upper chamber of the heart). The electrical impulses are generated there. The sinus node is also called the sinoatrial node or, for short, the SA node.
The electrical signal generated by the sinus node moves from cell to cell down through the heart until it reaches the atrioventricular node (AV node), a cluster of cells situated in the center of the heart between the atria and ventricles. The AV node serves as a gate that slows the electrical current before the signal is permitted to pass down through to the ventricles. This delay ensures that the atria have a chance to fully contract before the ventricles are stimulated. After passing the AV node, the electrical current travels to the ventricles along special fibers embedded in the walls of the lower part of the heart. Although there are different types of artificial pacemakers, all are designed to treat bradycardia, a heart rate that is too slow. Some pacemakers function continuously and stimulate the heart at a fixed rate or at an increased rate during exercise. A pacemaker can also be programmed to detect an overly long pause between heartbeats, and then stimulate the heart. For more information, see Artificial pacemaker.
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[mohammad qasaimeh]

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Graves disease ( صرعونا فيه بالاميونتي )

Graves disease: Generalized diffuse overactivity ("toxicity") of the entire thyroid gland which becomes enlarged into a goiter. Graves disease is the most common cause of hyperthyroidism.

There are three components to Graves disease:

• Hyperthyroidism (the presence of too much thyroid hormone),
• Ophthalmopathy specifically involving exophthalmos (protrusion of the eyeballs),
• Dermopathy with skin lesions.

The ophthalmopathy can cause sensitivity to light and a feeling of "sand in the eyes." With further protrusion of the eyes, double vision and vision loss may occur. The ophthalmopathy tends to worsen with smoking. The dermopathy of Graves disease is a rare, painless, reddish lumpy skin rash that of Graves disease is an autoimmune process. It is caused by thyroid-stimulating antibodies which bind to and activate the thyrotropinreceptor on thyroid cells.

Graves disease can run in families. The rate of concordance for Graves disease is about 20% among monozygotic (identical) twins, and the rate is much lower among dizygotic (nonidentical) twins, indicating that genes make only a moderate contribution to the susceptibility to Graves disease. No single gene is known to cause the disease or to be necessary for its development. There are well-established associations with certain HLA types. Linkage analysis has identified gene loci on chromosomes 14q31, 20q11.2, and Xq21 that are associated with susceptibility to Graves disease.
Factors that can trigger the onset of Graves disease include stress, smoking, radiation to the neck, medications (such as interleukin-2 and interferon-alpha), and infectious organisms such as viruses.
The diagnosis of Graves disease is made by a characteristic thyroid scan (showing diffusely increase uptake), the characteristic triad of ophthalmopathy, dermopathy, and hyperthyroidism, or blood testing for TSI (thyroid stimulating immunoglobulin) the level of which is abnormally high.
Current treatments for the hyperthyroidism of Graves disease consist of antithyroid drugs, radioactiveiodine, and surgery. There is regional variation in which of these measures tends to be used -- for example, radioactive iodine is favored in North America and antithyroid drugs nearly everywhere else. The surgery, subtotal thyroidectomy, is designed to remove the majority of the overactive thyroid gland. The disease is named for Robert Graves who in 1835 first identified the association of goiter, palpitations, and exophthalmos. Graves disease is also commonly known as diffuse toxic goiter.
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[mohammad qasaimeh]

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Sphenopalatine neuralgia

Sphenopalatine neuralgia: A distinctive syndrome of headaches, better known today as cluster
headache. There are two main clinical patterns of cluster headache -- the episodic and the chronic:

• Episodic: This is the most common pattern of cluster headache. It is characterized by 1-3 short attacks of pain around the eyes per day, with these attacks clustered over a stretch of 1-2 months followed by a pain-free remission, a breathing spell. The average length of remission is a year.
• Chronic: Characterized by the absence of sustained periods of remission, chronic cluster headache may start with no past history of cluster headaches, or it may emerge several years after the patient has experienced an episodic pattern of cluster headaches.

The episodic and acute forms of cluster headache may transform into one another, so it seems most likely that they are merely different-appearing clinical patterns of one and the same disease.
Although the mechanisms underlying cluster headache and migraine may have a degree of commonality, cluster headache looks to be different and distinct as a disease from migraine. For example, propranolol is effective for migraine but not cluster headache while lithium benefits cluster headache syndrome but not migraine. Cluster headache has also gone by a bevy of other confusing names including ciliary neuralgia, erythroprosopalgia, histamine cephalalgia, migrainous neuralgia, Raeder's syndrome, and vidian neuralgia
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[mohammad qasaimeh]

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Hematoma: An abnormal localized collection of blood in which the blood is usually clotted or partially clotted and is usually situated within an organ or a soft tissue space, such as within a muscle.
A hematoma is caused by a break in the wall of a blood vessel. The break may be spontaneous, as in the case of an aneurysm, or caused by trauma.
The treatment of a hematoma depends on its ******** and size. Treatment can involve draining the accumulated blood. A hematoma in or near the brain is particularly dangerous.

The word "hematoma" came into usage around 1850. It was devised from Greek roots -- hemat-, referring to the blood + -oma, from soma meaning body = a bloody body, or a collection of blood. The many different kinds of hematomas are defined by ******** and include:

• epidural hematoma,
• extradural hematoma,
• intracerebral hematoma,
• intracranial hematoma,
• nasal septum hematoma,
• subcutaneous hematoma,
• subdural hematoma

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[mohammad qasaimeh]

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Stereotactic

Stereotactic: Stereotactic refers to precise positioning in three-dimensional space. For example, biopsies, surgery or radiation therapy can be done stereotactically.
In a stereotactic needle biopsy, the spot to be biopsied is located three-dimensionally, the information is entered into a computer, and the computer calculates the information and positions a needle to remove the biopsy sample.
In stereotactic surgery, a system of three-dimensional coordinates is used to locate the site to be operated on.
In stereotactic radiotherapy, a number of precisely aimed beams of ionizing radiation are aimed from diverse directions and meet at a specific point to deliver the radiation treatment to that point.
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[mohammad qasaimeh]

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Hay fever

Hay fever: A seasonal allergy to airborne particles characterized by itchy eyes, runny nose, nasal
congestion, sneezing, itchy throat, and excess mucus.
Hay fever is a misnomer because it is not caused by hay and it does not produce a fever. It is also known as allergic rhinitis or pollinosis.
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[mohammad qasaimeh]

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Tachycardia

Tachycardia: A rapid heart rate, usually defined as greater than 100 beats per minute. The tachycardias include sinus tachycardia, paroxysmal atrial tachycardia (PAT), and ventricular tachycardia.
Sinus tachycardia is due to rapid firing of a normal structure called the sinoatrial (sinus) node which is the natural pacemaker of the heart. Sinus tachycardia occurs in response to exercise, exertion, excitement, pain, fever, excessive thyroid hormone, low blood oxygen (hypoxia), stimulant drugs (such as caffeine and amphetamines), etc.
Paroxysmal atrial tachycardia (PAT) consists of bouts of rapid, regular heart beating originating in the atrium (upper chamber of the heart). Often due to abnormalities in the AV node "relay station" that lead to rapid firing of electrical impulses from the atrium which bypass the AV node under certain conditions. These conditions include alcohol excess, stress, caffeine, overactive thyroid or excessive thyroid hormone intake, and certain drugs. PAT is an example of an arrhythmia where the abnormality is in the electrical system of the heart, while the heart muscle and valves may be normal. Ventricular tachycardia is an abnormal heart rhythm that is rapid, regular and originates from an area of the ventricle, the lower chamber of the heart. Ventricular tachycardias are most commonly associated with heart attacks or scarring of the heart muscle from previous heart attacks and are life-threatening.
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[mohammad qasaimeh]

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Hyperventilation

Hyperventilation: Overbreathing. This can cause dizziness, lightheadedness, weakness, shortness of breath, a sense of unsteadiness, muscle spasms in the hands and feet, and tingling around the mouth and fingertips. All of these symptoms are the result of abnormally low levels of carbon dioxide in the blood caused by overbreathing.
Hyperventilation is often due to anxiety or panic. Other less common causes include stimulant use; excessive use of aspirin; pulmonary disease such as asthma, chronic obstructive pulmonary disease (COPD), and pulmonary embolism; infection such as pneumonia or sepsis; heart disease such as congestive heart failure or heart attack; pain; and ketoacidosis when diabetes is out of control.
Reassurance can help relax breathing. Breathing in and out of a paper bag (to increase the level of carbon dioxide in the blood) is no longer recommended (because the level of carbon dioxide can rise too high). The opposite of hyperventilation is hypoventilation (underventilation).
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[mohammad qasaimeh]

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Lumpectomy

Lumpectomy: The surgical removal of a small tumor (a lump) which may or may not be benign (or malignant). Lumpectomy has come to refer specially to the removal of a lump from the breast. The word "lumpectomy" is a hybrid term. "Lump" is of Middle English origin while "-ectomy" comes from two Greek roots "ek" (out) + "tome" (a cutting) = a cutting of. So a lumpectomy is literally "a cutting out of a lump."
A lumpectomy is as opposed to a mastectomy in which the breast is removed. It is a more conservative approach to breast tumor surgery.
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