Term used to described a study in which either the investigator or the participant, but not both of them, is unaware of the nature of the treatment the participant is receiving. Also called single-masked.
- Single-payer health care
A system of health care characterized by universal and comprehensive coverage. Single-payer health care is similar to the health services provided by Medicare in the US. The government pays for care that is delivered in the private (mostly not-for-profit) sector. Doctors are in private practice and are paid on a fee-for-service basis from government funds. […]
- Sinoatrial node
The heart’s natural pacemaker, one of the major elements in the cardiac conduction system, the system that controls the heart rate. Abbreviated SA node. The SA node consists of a cluster of cells that are situated in the upper part of the wall of the heart’s right atrium, where the electrical impulses are generated. An […]
Curving in and out; in a serpentine, wavy form; winding. From the Latin noun “sinus,” which means “curve, fold, or hollow’ and also was borrowed directly to designate the “and out; in a serpentine, wavy form; winding.
Sinusitis. 2. A channel permitting the passage of blood or lymph fluid that is not a blood or lymphatic vessel, such as the sinuses of the placenta. 3. A tract or fistula leading to a cavity which may be filled with pus. The word was borrowed from the Latin noun “sinus,” which means “curve, fold, […]
- Sinus arrhythmia
The normal increase in heart rate that occurs during inspiration (when you breathe in). This is a natural response and is more accentuated in children than adults. The “sinus” refers to the natural pacemaker of the heart which is called the sinoatrial (or sinus) node. It is located in the wall of the right atrium […]