seizure, complex partial A form of partial seizure during which the person loses awareness. The patient does not actually become unconscious, and he or she may carry out actions as complex as walking, talking, or driving. The patient may have physical, sensory, and thought disturbances. When the seizure ends, the patient has no memory of…
seizure, atonic A seizure in which the person suddenly loses muscle tone and cannot sit or stand upright. Also known as drop attack and drop seizure.
seizure, absence A seizure that takes the form of a staring spell: The person suddenly seems to be “absent.” There is a brief loss of awareness, which can be accompanied by blinking or mouth twitching. Absence seizures have a very characteristic appearance on an EEG. Also known as petit mal seizure.
seizure Uncontrolled electrical activity in the brain that may produce a physical convulsion, minor physical signs, thought disturbances, or a combination of symptoms. The type of symptoms and seizures experienced depend on where the abnormal electrical activity takes place in the brain, what its root cause is, and such factors as the patient’s age and…
Segawa dystonia See dopa-responsive dystonia.
sedimentation rate A blood test that detects and monitors inflammation in the body. Abbreviated sed rate. The sed rate measures the rate at which red blood cells in a test tube separate from blood serum over time, becoming sediment at the bottom of the test tube. The sed rate increases as inflammation increases. The sed…
sedative A drug that calms a patient, easing agitation and permitting sleep. Sedatives generally work by modulating signals within the central nervous system. If sedatives are misused or accidentally combined, as in the case of combining prescription sedatives with alcohol, they can dangerously depress important signals that are needed to maintain heart and lung function….
section 1 In anatomy, a slice of tissue. A biopsy obtained via surgery is usually sectioned (sliced), and these sections are inspected under a microscope. 2 In obstetrics, short for caesarean section. 3 In surgery, the division of tissue during an operation.
secretin A hormone that is made by glands in the small intestine whose primary function is the stimulation of pancreatic secretion. Secretin is often administered as part of the endoscopy process. Commercially available secretin is either porcine (from pigs) or a synthesized form of human secretin.
secondhand smoke Smoke that comes from the burning end of a cigarette or that is exhaled by smokers. Inhalation of secondhand smoke is called involuntary or passive smoking. It can cause the same illnesses, including lung cancer, that actually smoking cigarettes causes. Also known as environmental tobacco smoke (ETS).
second stage of labor The part of labor that lasts from the full dilatation of the cervix until the baby is completely out of the birth canal. Also known as the stage of expulsion. See also labor.
second cranial nerve See optic nerve.