Category: A

Splenic tissue found outside the main bulk of the organ, usually but not always within the peritoneal cavity. If the patient is asymptomatic, the accessory spleen may be found only as an incidental mass on an abdominal scan; alternatively, the condition may exacerbate certain illnesses (e.g., immune thrombocytopenic purpura).  

The spinous process of the sphenoid bone.  

Acute traumatic injury of the spinal cord. Signs and symptoms depend upon the vertebral level injured and degree of injury. Damage may occur both as a result of the initial injury and any inflammatory response or swelling that occurs in the next 48 to 72 hr. Therapy for this condition includes immobilization, high doses of…

A clear region in the cytoplasm close to the nucleus and usually containing a centriole or diplosome (a divided centriole).  

Defective speech due to muscular incoordination, usually the result of cerebellar disorder.  

Spectrum recorded after light rays have passed through a substance capable of absorbing some of the wavelengths passing through. This spectrum is specific for various chemicals.  

The property of mature B and T lymphocytes that enables them to respond to specific foreign antigens entering the body. Antigen specificity requires mature B and T cells that have been previously exposed to the antigen and, therefore, are able to recognize it again and respond by neutralizing or destroying it. The exact process by…

The area in the trachea, bronchi, and air passages containing air that does not reach the alveoli during inspiration and is not involved in gas exchange.  

Crackles and wheezes superimposed on the normal breath sounds; indicative of respiratory disease. Most adventitious lung sounds can be divided into continuous (wheezing) and discontinuous (crackles) according to acoustical characteristics.  

The lack of any sound heard over the chest of the patient during auscultation.