Common side effects include no periods, abdominal pain, headaches, and anxiety. Other serious side effects include bone loss, blood clots, allergic reactions, depression, and liver problems. Use is not recommended during pregnancy as it may harm the baby. It works by decreasing the body's release of gonadotropins.
The brain makes up the largest portion of the central nervous system, and is often the main structure referred to when speaking of the nervous system. The brain is the major functional unit of the central nervous system. While the spinal cord has certain processing ability such as that of spinal locomotion and can process reflexes, the brain is the major processing unit of the nervous system.
The functional unit of the nervous tissue is the neuron, or nerve cell, which has a unique structure that is specialized to transmit signals called nerve impulses. A nerve cell consists a body and two or more extensions called dendrites and axons, which may be as long as a meter in humans.