| partial pressure | The pressure exerted by a single component of a mixture of gases, commonly expressed in mm Hg or torr; for a gas dissolved in a liquid, the partial pressure is that of a gas that would be in equilibrium with the dissolved gas. Formerly, symbolised by p, followed by the chemical symbol in capital letters (e.g., pCO2, pO2); now, in respiratory physiology, P, followed by subscripts denoting location and/or chemical species (e.g., PCO2, PO2, PaCO2). (05 Mar 2000) |
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| partial pressures | <chemistry> The independent pressure exerted by different gases in a mixture. (09 Jan 1998) |
| partial response | <oncology> A decrease of at least 50 percent in the sum of the measurements of all evaluable target lesions or tumours seen in a study. (16 Dec 1997) |
| partial sclerectasia | Partial protrusion of a portion of the sclera, typically seen in severe myopia. See: staphyloma. (05 Mar 2000) |
| partial seizure | <neurology> A brief temporary alteration in movement, sensation or autonomic nerve function caused by abnormal electrical activity in a localised area of the brain. Focal seizures (i.e. Partial or Jacksonian seizures) usually cause no change in awareness or alertness. An example of a focal (partial) seizure would be rhythmic muscle contractions in one area of the body: lip smacking, mouth movements, drooling, head turning, eye movements or seemingly purposeful movements (for example picking at clothes). Other presentations may be strictly sensory with abnormal numbness, tingling or a crawling sensation to the skin. More unusual symptoms include changes in speech, thought, personality, mood, sensation of deja vu or hallucinations. (27 Sep 1997) |
| partial-thickness burn | A burn involving the epidermis and dermis and usually forming blisters that may be superficial, or by deep dermal necrosis, followed by epithelial regeneration extending from the skin appendages. Synonym: partial-thickness burn. (05 Mar 2000) |
| partial-thickness flap | A flap of a portion of the skin, i.e., the epidermis and part of the dermis, or of part of the mucosa and submucosa, but not including the periosteum. Synonym: partial-thickness flap. (05 Mar 2000) |
| partial-thickness graft | A graft of portions of the skin, i.e., the epidermis and part of the dermis, or of part of the mucosa and submucosa, but not including the periosteum. Synonym: partial-thickness graft, split-skin graft. (05 Mar 2000) |
| partial thromboplastin time | Test of the intrinsic (factors viii, ix, xi, and xii) and common (fibrinogen, prothrombin, factors v and x) pathways of coagulation in which a mixture of plasma and phospholipid platelet substitute (e.g., crude cephalins, soybean phosphatides) is recalcified and the time required for the appearance of fibrin strands measured. Activation may be provided by contact with the glass tube or exposure to activators (e.g., ellagic acid, particulate silicates such as diatomaceous earth or kaolin) before addition of the calcium chloride. It is used as a screening test and to monitor heparin therapy. (12 Dec 1998) |
| partial volume | The actual volume occupied by one species of molecule or particle in a solution; the reciprocal of the density of the molecule. (05 Mar 2000) |
| removable partial denture | A partial denture which supplies teeth and associated structures on a partially edentulous jaw, and which can be readily removed from the mouth. Synonym: removable bridge. (05 Mar 2000) |
| complex partial seizure | <neurology> Seizures with elaborate and multiple sensory, motor, and/or psychic components. A common feature is the clouding of consciousness and amnesia for the event. Some clinical manifestations may include more complex behaviours like burst of anger, emotional outbursts, fear or automatisms. The EEG often reveals spike discharges in the temporal lobe during sleep. (05 Jan 1998) |
| hearing loss, partial | A condition in which the sense of hearing, although defective, is functional with or without a hearing aid. The hearing level for speech is approximately 40-70 decibels I.s.o. (international organization for standardization) or 30-60 db a.s.a. (american standards association). (12 Dec 1998) |
| simple partial seizure | A partial seizure that is not associated with impairment of consciousness. (05 Mar 2000) |
| hysterectomy, partial | The uterus is sugically removed but the cervix is left is left in place. Also called a subtotal hysterectomy. (12 Dec 1998) |