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.
The reflex arc is the action unit of the nervous system. In this arc, a sense receptor initiates nerve impulses that travel by way of a sensory fiber to the central nervous system where integration takes place. Following this, nerve impulses travel by way of motor neurons to either a gland or muscle that then reacts.