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.
A reflex arc is a neural pathway that controls a reflex action. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord.his characteristic allows reflex actions to occur relatively quickly by activating spinal motor neurons without the delay of routing signals through the brain, although the brain will receive sensory input while the reflex is carried out.