For this IBDP Biology blog post, we will be understanding the basic function and definition for the reflex arc and the main components of neurobiology, let's go!
The terms stimulus, response and reflex
Stimulus: a change in either the internal or external environment that is detected by a receptor and elicits a response
Response: a change in an organism, produced by a stimulus
Reflex: a rapid, unconscious response to a stimulus
Explaining the role of receptors, sensory & motor neurons
Receptors : to detect a stimulus; sensory cells, or nerve endings of sensory neurons
Sensory neurons: receive messages from receptors across synapses from sensory cells or from nerve endings of sensory neurons. Transmit message to CNS
Relay neurons: receive messages from sensory neurons across synapses. Transmit messages to motor neurons that cause an appropriate response
Motor neurons: receive messages from relay neurons across synapses. Transmit messages to effector organs
Effectors: receive messages from motor neurons. Produce a response such as muscles contract (or relax) ,glands secrete
Reflex Arc
The order is : Stimulus -> Receptor -> Sensory -> CNS -> Motor -> Effector -> Response
That's all the main definitions! Good job!
References:
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.researchgate.net%2Ffigure%2FReflex-arc-It-consists-of-a-receptor-a-sensory-neuron-a-reflex-center-spinal-cord-a_fig1_263858109&psig=AOvVaw0mlTsi6EcOV6PIPvo9BxrO&ust=1627285312198000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCJiDxqrc_fECFQAAAAAdAAAAABAD
Drafted by Venetia (Biology)