natremia The presence of sodium ions in the blood. Derived terms . dysnatremia; hypernatremia; hyponatremia; natremic; Translations
A reflex arc is a nerve pathway in the body of humans and some animals that connects certain muscle groups to others, without involving the brain. These sorts of pathways primarily control involuntary movements in response to some sort of stimulus.
More information about the simple reflex arc is shown in Figure (2), below. Following either simple reflex arc response, or processing by the brain, neural 'instructions' may be sent via a motor neurone to an effector (usually a muscle or gland). In this way, the effector is instructed to take action.