Science / Biology / Effector: In a closed system, the element that initiates an action in response to a signal from a sensor. In human systems, a muscle or gland often serves as an effector.


Science / Biology / Sensor: In a closed system, the element that detects change and signals the effector to initiate a response. MORE

Reflex Arc

Science / Biology / Reflex Arc: Pathway of neurons, effector(s) and sensory receptors that participate in a reflex. MORE

Motor Neurons

Science / Biology / Motor Neurons: Neurons that receive signals from interneurons and transfer the signals to effector cells that produce a response. Nerve cells connected to a muscle or gland. Sometimes also known as effector neurons. MORE


Science / Biology / Neurotransmitters: Chemicals released from the tip of an axon into the synaptic cleft when a nerve impulse arrives; may stimulate or inhibit the next neuron. The chemical that crosses the synaptic cleft and causes the t MORE