Retinal artery occlusion Health Dictionary

The way that the TEETH ?t together when the jaws close. Also the closing or obstruction of a duct, hollow organ, or blood vessel.... occlusion

This artery arises from the brachial artery at the level of the neck of the radius. It passes down the forearm to the wrist, where it is easily palpated laterally. It then winds around the wrist to the palm of the hand to supply the ?ngers. (See ARTERIES.)... radial artery

A branch of the external carotid artery that is the main vessel supplying blood to the temple and scalp.... temporal artery

A blood vessel that carries blood away from the heart. Systemic arteries carry blood pumped from the left ventricle of the heart to all parts of the body except the lungs. The largest systemic artery is the aorta, which emerges from the left ventricle; other major systemic arteries branch off from the aorta. The pulmonary arteries carry blood from the right ventricle to the lungs.

Arteries are tubes with thick, elastic, muscular walls able to withstand the high pressure of blood flow. The structure of arteries helps to even out the peaks and troughs of blood pressure caused by the heartbeat, so that the blood is kept flowing at a relatively constant pressure. (See also arteries, disorders of.)... artery

The artery that runs down the inner side of the upper arm, between the armpit and the elbow.... brachial artery

Any of the main arteries of the neck and head. There are 2 common carotid arteries (left and right), each of which divides into 2 main branches (internal and external).

The left carotid arises from the aorta and runs up the neck on the left side of the trachea (windpipe). The right carotid arises from the subclavian artery (which branches off the aorta) and follows a similar route on the right side of the

neck. Just above the level of the larynx (voice-box), each carotid artery divides to form an external carotid artery and an internal carotid artery. The external arteries have multiple branches that supply most tissues in the face, scalp, mouth, and jaws; the internal arteries enter the skull to supply the brain and eyes. At the base of the brain, branches of the 2 internal carotids and the basilar artery join to form a ring of vessels called the circle of Willis. Narrowing of these vessels may be associated with transient ischaemic attack (TIA); obstruction of them causes a stroke. carpal tunnel syndrome Numbness, tingling, and pain in the thumb, index finger, and middle fingers caused by compression of the median nerve at the wrist. Symptoms may be worse at night. The condition results from pressure on the nerve where it passes into the hand via a gap (the “carpal tunnel’’) under a ligament at the front of the wrist. It is common among keyboard users. It also occurs without obvious cause in middleaged women, and is associated with pregnancy, initial use of oral contraceptives, premenstrual syndrome, rheumatoid arthritis, myxoedema, and acromegaly.

The condition often disappears without treatment.

Persistent symptoms may be treated with a corticosteroid drug injected under the ligament, or the ligament may be cut to relieve pressure on the nerve.... carotid artery

A major blood vessel that supplies oxygenated blood to the leg. The femoral artery is formed in the pelvis from the iliac artery (the terminal branch of the aorta). It then runs from the groin, down in front of the thigh, and passes behind the knee to become the popliteal artery, which branches again to supply the lower leg.... femoral artery

Narrowing of the coronary arteries, which supply blood to the heart, leading to damage or malfunction of the heart. The most common heart disorders due to coronary artery disease are angina pectoris and myocardial infarction (heart attack). The usual cause of narrowing of the arteries is atherosclerosis, in which fatty plaques develop on the artery linings. The vessel can become totally blocked if a blood clot forms or lodges in the narrowed area. Atherosclerosis has many interrelated causes including smoking, a high-fat diet, lack of exercise, being overweight, and raised blood cholesterol levels. Other factors include a genetic predisposition and diseases such as diabetes mellitus and hypertension.

The first symptom of coronary artery disease is frequently the chest pain of angina. Treatment is with drugs such as glyceryl trinitrate and other nitrate drugs, beta-blockers, calcium channel blockers, potassium channel activators, and vasodilator drugs. If drug treatment fails to relieve the symptoms, or there is extensive narrowing of the coronary

arteries, blood flow may be improved by balloon angioplasty or coronary artery bypass surgery.... coronary artery disease

Separation of the retina from the outer layers at the back of the eye. Detachment may follow an eye injury but usually occurs spontaneously. It is usually preceded by a retinal tear, and is more common in highly myopic (shortsighted) people and in people who have had cataract surgery.

The detachment is painless. The first symptom is either bright flashes of light at the edge of the field of vision, accompanied by floaters, or a black “drape” obscuring vision.

Urgent treatment is required and usually involves surgical repair of the underlying tear. If the macula (site of central vision) has not been detached, the results can be excellent.... retinal detachment

Blockage of a vein carrying blood away from the retina.

It usually results from thrombosis in the affected vein, and is more common in people who have glaucoma.

Retinal vein occlusion may cause visual disturbances, glaucoma, or blindness.... retinal vein occlusion

When coronary arteries, narrowed by disease, cannot supply the heart muscle with su?cient blood, the cardiac circulation may be improved by grafting a section of vein from the leg to bypass the obstruction. Around 10,000 people in the United Kingdom have this operation annually and the results are usually good. It is a major procedure that lasts several hours and requires the heart to be stopped temporarily, with blood circulation and oxygenation taken over by a HEART-LUNG MACHINE.... coronary artery vein bypass grafting (cavbg)

A narrowed or blocked coronary artery (see ARTERIES) can compromise the blood supply to the heart muscle (see HEART, DISEASES OF). A supportive tube or stent passed into each affected artery can restore the blood supply. The stent has a HEPARIN coating to stop blood clots from forming. Since it was ?rst performed in 1987, intracoronary stents have cut the reblockage rate from one in three patients who have had coronary ANGIOPLASTY to fewer than one in ten in cases where a stent was used with angioplasty.... intracoronary artery stenting

See: BLEEDING. ... eyes  - retinal haemorrhage

Either of the 2 main arteries that supply the tissues of the heart with oxygen-rich blood. These are

known as the left and right main coronary arteries and arise directly from the aorta. The term coronary artery is also applied to any of the arteries that branch off from the main coronary arteries, such as the left circumflex artery and the left anterior descending artery. Blockage of a coronary artery as a result of atherosclerosis can lead to myocardial infarction.

(See also coronary artery disease.)... coronary artery

A major heart operation to bypass narrowed or blocked coronary arteries using additional blood vessels (such as a mammary artery) to improve blood flow to the heart muscle. This operation is used when symptoms of coronary artery disease have not been relieved by drugs or balloon angioplasty.

Before surgery, sites of blockage in the arteries are identified using angiography. In some cases, minimally invasive surgery can be used, avoiding the need to stop the heart and use a heart–lung machine during the operation. The long term outlook after a bypass is good, but the grafted vessels may also eventually become blocked by atherosclerosis.... coronary artery bypass

Bleeding into the retina from 1 or more blood vessels, due to diabetes mellitus, hypertension, or retinal vein occlusion. When the macula

(site of central vision) is involved, vision is severely impaired.

Peripheral haemorrhages may be detected only when the eye is examined with an ophthalmoscope.... retinal haemorrhage

The development of a split in the retina, usually caused by degeneration.

A tear is more common in people with severe myopia.

A retinal tear may also be caused by a severe eye injury.

Retinal detachment usually follows a retinal tear.

If a retinal tear is found before there is any detachment, the hole is sealed by laser treatment or cryopexy (application of extreme cold).... retinal tear

(ARN) severe inflammation and necrosis of the retina associated with inflammation and blockage of retinal blood vessels, haemorrhage and death of retinal tissue, and retinal detachment. It may affect both eyes (bilateral acute retinal necrosis, BARN), and visual prognosis is poor. ARN is thought to be due to viral infection.... acute retinal necrosis

an artery in the base of the brain, formed by the union of the two vertebral arteries. It extends from the lower to the upper border of the pons Varolii and then divides to form the two posterior cerebral arteries.... basilar artery

see innominate artery.... brachiocephalic artery

(carotid stenosis) narrowing of the carotid artery, which reduces the supply of blood to the brain and is a cause of strokes. It is treated by surgical excision or bypass of the narrowed segment (see also endarterectomy) or by inserting a *stent into the carotid artery.... carotid artery stenosis

(CTO) a complete arterial blockage (usually coronary) that has been present for at least three months. Fibrosis and calcification at the site of occlusion are well established by this time, making *percutaneous coronary intervention to open the artery much more difficult.... chronic total occlusion

(CABG) *coronary revascularization in which a segment of a coronary artery narrowed by atheroma is bypassed by an *autologous section of healthy saphenous vein or internal mammary artery at *thoracotomy. The improved blood flow resulting from one or more such grafts relieves *angina pectoris and reduces the risk of *myocardial infarction. Recently developed techniques of *minimally invasive surgery have enabled the operation to be performed without the need for thoracotomy.... coronary artery bypass graft

the terminal branch of an artery, which does not communicate with other branches. The tissue it supplies is therefore probably completely dependent on it for its blood supply.... end artery

the combination of major acne, *pilonidal sinus, chronic scalp *folliculitis, and *hidradenitis suppurativa.... follicular occlusion tetrad

a fetal artery lying in the *hyaloid canal of the eye and supplying the lens.... hyaloid artery

(brachiocephalic artery) a short artery originating as the first large branch of the *aortic arch, passing upwards to the right, and ending at the lower neck near the right sternoclavicular joint. Here it divides into the right common carotid and the right subclavian arteries.... innominate artery

the artery that conveys blood from the heart to the lungs for oxygenation: the only artery in the body containing deoxygenated blood. It leaves the right ventricle and passes upwards for 5 cm before dividing into two, one branch going to each lung. Within the lungs each pulmonary artery divides into many fine branches, which end in capillaries in the alveolar walls. See also pulmonary circulation.... pulmonary artery

either of two large arteries arising from the abdominal aorta and supplying the kidneys. Each renal artery divides into an anterior and a posterior branch before entering the kidney.... renal artery

1. (retinene) n. the aldehyde of retinol (*vitamin A). See also rhodopsin. 2. adj. see retina.... retinal

separation of the retina from its insertion at the ora serrata (the anterior margin of the retina, lying just posterior to the ciliary body). This acts as a retinal tear and causes a *retinal detachment.... retinal dialysis

either of two arteries that originate from the abdominal aorta and travel downwards to supply the testes.... spermatic artery

(SPA) a surgical procedure to identify and occlude the sphenopalatine artery in the nose using endoscopic surgery. It is used in the treatment of severe epistaxis (nosebleed).... sphenopalatine artery ligation

either of two arteries supplying blood to the neck and arms. The right subclavian artery branches from the innominate artery; the left subclavian arises directly from the aortic arch.... subclavian artery

blocking of the Fallopian tubes. This is achieved by surgery as a means of *sterilization; it is also a result of *pelvic inflammatory disease.... tubal occlusion

a branch of the brachial artery arising at the elbow and running deep within the muscles of the medial side of the forearm. It passes into the palm of the hand, where it unites with the arch of the radial artery and gives off branches to the hand and fingers.... ulnar artery

a method of embolizing the uterine artery under radiodiagnostic control (see embolization). It has been successful in controlling postpartum haemorrhage and can also be used in treating fibroids, correcting arterial or venous malformations of the genital tract, and terminating abdominal and cervical pregnancies.... uterine artery embolization