Melatonin receptors are found in the SCN and the pituitary gland of the brain, as well as in the ovaries, blood vessels, and intestinal tract. There is a high concentration of receptors in the SCN because this is where melatonin mediates the majority of its affects on circadian rhythm. The binding of melatonin to its receptors on the pituitary gland and the ovaries appears to play a role in regulating the release of reproductive hormones in females. For example, the timing, length, and frequency of menstrual cycles in women are influenced by melatonin.
The process by which the nervous system bypasses the brain to increase response time is called a A. feedback mechanism. B. contraction. C. reflex. D. hormonal response. The process by which the nervous system bypasses the brain to increase response time is called a REFLEX. Log in to see link for more information.
These are Fight or Flight responses. In these types of situations, your sympathetic nervous system is called into action - it uses energy - your blood pressure increases, your heart beats faster, and digestion slows down. Notice in the picture on the left that the sympathetic nervous system originates in the spinal cord. Specifically, the cell bodies of the first neuron (the preganglionic neuron) are located in the thoracic and lumbar spinal cord. Axons from these neurons project to a chain of ganglia located near the spinal cord.