Medical terms - Letter A (page 23) | MedicalVocabulary.org

Aorta, coarctation of the

A congenital constriction of the aorta, impeding the flow of blood below the level of the constriction and increasing blood pressure above the constriction. Symptoms may not be evident at birth but may develop as soon…
Aorta, descending

The descending aorta is the part of the aorta, the largest artery in the body, that runs down through the chest and the abdomen. The descending aorta starts after the arch of the aorta and ends by splitting into two…
Aorta, thoracic

The thoracic aorta is a section of the aorta, the largest artery in the body, within the chest. Specifically, the thoracic aorta is that part of the aorta that starts after the arch of the aorta and runs down to the…
Aortal

Pertaining to the aorta, the largest artery in the body. Aortal is not often encountered (except in The New York Times crossword). The preferred term is aortic.
Aortic

Pertaining to the aorta, the largest artery in the body. 'Aortic' is in common usage as, for example, in an abdominal aortic aneurysm. The term 'aortal' has the same meaning but is rarely encountered (except in The New…
Aortic aneurysm

An outpouching (a local widening) of the largest artery in the body, the aorta, involving that vessel in its course above the diaphragm (thoracic aortic aneurysm) or, more commonly, below the diaphragm (abdominal aortic…
Aortic arch

The second section of the aorta. The aorta first ascends, then bends, and then descends. The bend is the aortic arch. It gives off the brachiocephalic trunk, the left common carotid artery, and the left subclavian…
Aortic arch syndrome

1. Any disorder that causes occlusion of the arteries that arise from the aortic arch. 2. Synonym for Takayasu disease.3. The subclavian steal syndrome
Aortic atresia

Congenital absence of the normal valvular opening from the left ventricle of the heart into the aorta. Atresia here refers to the absence of a normal opening.
Aortic dissection

Aortic dissection: A progressive tear in the aorta. The inner lining (intima) of the aorta tears and blood surges through the tear, creating a new false channel and separating (dissecting) the middle layer (media) from…
Aortic insufficiency

Incomplete closure of the aortic valve resulting in aortic regurgitation, the return of blood from the aorta into the left ventricle of the heart
Aortic regurgitation

The return of blood from the aorta into the left ventricle of the heart due to aortic insufficiency, incomplete closure of the aortic valve
Aortic stenosis

Aortic stenosis: Narrowing (stenosis) of the heart valve between the left ventricle of the heart and the aorta. This narrowing impedes the delivery of blood through the aorta to the body and makes it tough for the heart…
Aortic valve

One of the four valves in the heart, this valve is situated at exit of the left ventricle of the heart where the aorta (the largest of all arteries) begins. The aortic valve lets blood from the left ventricle be pumped…
Aortic valve, bicuspid

Whereas the normal aortic valve in the heart has three flaps (cusps) that open and close, a bicuspid valve has only two. There may be no symptoms in childhood, but in time the valve may become stenotic (narrowed)…
Aortitis

Inflammation of the aorta. The causes of aortitis include syphilis or rheumatic fever
AP

AP is a versatile abbreviation. It serves in cardiology to abbreviate angina pectoris (AP) and arterial pressure (AP). In endocrinology, it stands for the anterior pituitary (AP). And in anatomy, AP means…
AP (anteroposterior)

In anatomy, AP stands for anteroposterior: from front-to-back. For example, an AP X-ray of the chest is taken from front-to-back. AP in this respect is the opposite of PA, which stands for posteroanterior: from…
AP, X-ray

An X-ray picture in which the beams pass from front-to-back (anteroposterior). As opposed to a PA (posteroanterior) film in which the rays pass through the body from back-to-front
APA

1. American Psychiatric Association. 2. American Psychological Association. 3. American Podiatry Association. 4. Antiphospholipid antibody. 5. Alkaline phosphatase activity
APC

APC has several very different meanings in medicine. See each of the following separate entries:1. APC (gene).2. APC (immunology).3. APC (medication)
APC (gene)

A major gene that is involved in causing colorectal cancer. APC is involved in both sporadic and familial forms of colorectal cancer. A mutation in the APC gene is the earliest detectable molecular abnormality in…
APC (immunology)

Antigen-presenting cell, a cell that can 'present' antigen in a form that T cells can recognize it. Among the APCs are B cells and cells of the monocyte lineage including macrophages
APC (medication)

Aspirin, phenacetin, and caffeine (a pill containing all three)
APECED (autoimmune polyendocrinopathy)

Laxative. Used both as a noun (an aperient is a laxative) and adjective (prunes are an aperient fruit). From the Latin "aperiens" meaning to uncover, open (in this case, the bowels)
Aperient

Laxative. Used both as a noun (an aperient is a laxative) and adjective (prunes are an aperient fruit). From the Latin 'aperiens' meaning to uncover, open (in this case, the bowels
Apert syndrome

A malformation syndrome characterized by a high short skull, underdevelopment of the midface, soft tissue and bony ('mitten glove') fusion of fingers and toes, fusion of the neck vertebrae, and varying degrees of…
Apert syndrome acrocephalosyndactyly

An inherited disorder causing abnormalities of the skull, face and hands and feet. There is premature closure of some of the sutures of the skull (craniosynostosis) resulting in an abnormally shaped head (which is…
Apex

From the Latin meaning summit, the apex is the tip of a pyramidal or rounded structure, like the lung or the heart. The apex of the lung is indeed its tip, its rounded most superior portion. The apex of the heart is…
Apgar

Abbreviation for the Apgar score, a practical method of evaluating the physical condition of a newborn infant shortly after delivery. The Apgar score is a number arrived at by scoring the heart rate, respiratory effort…
Apgar score

El ODYvAlign=top bgColor=#cccccc colSpan=2> vAlign=top width='100%' bgColor=#ffffff>Our Apgar score Main Article provides a comprehensive look at the who, what, when and how of Apgar score Apgar score: A practical…
Aphagia

Inability to eat. From the Greek prefix 'a-' meaning 'not' + 'phago' meaning 'to eat' + not to eat.
Aphakia

Absence or loss of the eye's natural crystalline lens, as after cataract removal. From a-, without + phacos, the Greek word for a lentil bean. The ancients thought (quite correctly) that the lens of the eye was shaped…
Aphasia

Aphasia: One in a group of speech disorders in which there is a defect or loss of the power of expression by speech, writing, or signs, or a defect or loss of the power of comprehension of spoken or written language…
Aphasia, acquired epileptiform

See Landau-Kleffner syndrome
Aphasia, amnesic

See Anomia
Aphasia, amnestic

See Anomia
Aphasia, anomic

See Anomia
Aphasia, nominal

See Anomia
Aphasia, primary progressive

See: Primary progressive aphasia
Apheresis

The process of removing a specific component from blood and returning the remaining components to the donor, in order to collect more of one particular part of the blood than could be separated from a unit of whole…
Aphonia

Inability to speak.
Aphrasia

The inability to speak or understand phrases
Aphthous ulcer

Aphthous ulcer: A small sensitive painful ulcer crater in the lining of the mouth. Commonly called a canker sore. Aphthous ulcers are one of the most common problems that occur in the mouth. About 20% of the population…
Apical

The adjective for apex, the tip of a pyramidal or rounded structure, like the lung or the heart. For example, an apical lung tumor is a tumor located at the top of the lung.
Apiphobia

Fear of bees. A phobia is an unreasonable sort of fear that can cause avoidance and panic. Phobias are a relatively common type of anxiety disorder. Phobias can be treated with cognitive behavioral therapy using…
APL

Abbreviation for acute promyelocytic leukemia, a malignancy of the bone marrow in which there is a deficiency of mature blood cells in the myeloid line of cells and an excess of immature cells called promyelocytes. APL…
Aplasia

Failure to develop. If something develops and then wastes away, that is atrophy.
Aplasia of the breast

Breast: A rare condition wherein the normal growth of the breast or nipple never takes place. They are congenitally absent. There is no sign whatsoever of the breast tissue, areola or nipple. There is nothing there…
Aplastic anemia

Anemia due to failure of the bone marrow to produce blood cells, including red and white blood cells as well as platelets. Aplastic anemia frequently occurs without a known cause. Known causes include exposure to…