Upon feeling a sharp pain, impulses from a sensory receptor in the skin pass along a sensory neuron to the central nervous system. -The neuron enters the spinal cord through the dorsal root. -When an impulse from the sensory neuron arrives in the synapse with a short relay neuron, a transmitter is released which causes an impulse to be sent along the relay neuron. -When the impulse reaches the synapse between the relay neuron and a motor neuron returning to the arm again and another transmitter chemical is released. -In this example the impulse travels in the hand muscles of the upper arm, causing them to contract and move your hand away sharply.
A reflex arc occurs when a person has an involuntary and fast response to a stimulus. These reactions are extremely important as they allow a person to respond to a threat quickly to minimize damage. The reflex arc that happened in this case would look something like this:
First, a receptor in the skin of a woman reacted to the stimulus of the bee sting.
Then, the sensory neuron communicates with the relay neuron, which allows the information to be passed to a motor neuron.
After, the motor neuron send electrical impulses to an effector.
Finally, the effector allows the muscles to contract, which enable the woman to move her hand away.
The answer should be A, as anorexia nervosa is when someone worries far too much about their weight and begin to eat far less, becoming severely underweight.
