The nervous system directly stimulates endocrine glands to release hormones, which is referred to as neural stimuli. Hormones can also affect the nervous system; for example, mood swings are seen due to low estrogen level during menstruation.

The nervous system sends signals to the endocrine system for production and release of hormones such as during emergency conditions. The neural stimuli are sent to the adrenal glands that release epinephrine and norepinephrine. Similarly, blood glucose levels can increase during stress by sending a neural impulse to the pancreas to increase the production of glucagon. This increases blood sugar levels.

Similarly, when the level of luteinizing hormone is reduced in the body, commonly seen during menstruation, the signals are sent to the brain that causes bad mood or mood swings. Hormone such as dopamine also acts as neurotransmitter so can affect nerve impulse transmission.

Key Points

• The nervous system can regulate the secretion of enzymes from the endocrine gland by sending neural stimuli.

• The endocrine system and hormone levels in the blood can affect the nervous system.

• Some molecules like dopamine act both as a neurotransmitter and hormone.

Key Terms

dopamine: it is a neurohormone produced from the hypothalamus that can act as hormone as well as a neurotransmitter

neurotransmitter: chemicals which transmit signals across a chemical synapse from one neuron to another organ

epinephrine: (adrenaline) an amino acid-derived hormone secreted by the adrenal gland in response to stress

adrenal glands: glands located above the kidneys that secrete adrenaline

glucagon: a hormone secreted by the pancreas to cause cells to release glucose into the blood