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 basic functional unit of the brain is the neuron, a special cell that sends electrochemical signals to other neurons (across a synaptic gap) and thereby creates those patterns that make up what we think of as the mind. The complexity of the task requires a fairly inconceivable 100 billion neurons, interconnected via trillions of synapses. A single firing neuron might communicate to thousands of others in a single moment. No computer comes close to the complexity of these communicating bits of organic matter. What's more, for each neuron there are some 10 to 50 glial cells providing structural support, protection, resources and more.