Reflexes

• Reflex arc: A series of neurons that respond to a stimulus and carry the response back to the stimulus
• Reflex arc steps: stimulus, receptor, sensory neuron, relay neuron, motor neuron, effector, response
• Receptor: a cell that is able to respond and transmit a signal to a sensory nerve
• Sensory neuron: carries information from the receptors to the CNS
• Relay neuron: A neuron that connects and passes impulses from sensory neurons to motor neurons.
• Motor neuron: A neuron that transmits impulses from the CNS to effectors
• Effector: an organ or a gland that carries out the response
• Impulse: a sudden strong and unreflective urge or desire to act, can only travel in one direction
• Neurons: a specialised cell, they are elongated to allow impulses to travel long distances in the body
• A neuron is made up of dendrites, cell body, nucleus, myelin sheath along an axon
• Dendrite: receives information from other cells
• Cell Body: contains the nucleus which controls all activities within the cell
• Synapse: where two neurones meet, there is a gap between them called synaptic cleft
• The synapse allows communication between neurones by releasing chemicals into the synaptic cleft that cross over to the next neurone
• Myelin Sheath: insulates the axon so it conducts electrical signals faster