Neuroanatomy – Anatomy of the Nervous System

Neuroanatomy – Anatomy of the Nervous System

The nervous system is composed of nerve cells (known as neurons). Nerves are composed of bundles of neurons surrounded by an insulating layer, rather like an electrical cable. Nerves work by conducting electrical signals up and down the nervous system in order to release substances known as neurotransmitters to transmit information.

The nervous system is composed of nerves arranged in a highly organized fashion. There two main components of the nervous system are the central nervous system (CNS) and the peripheral nervous system (PNS).

The CNS consists of the brain and spinal cord. Parkinson’s Disease, epilepsy, dementia, and multiple sclerosis are among the neurological conditions affecting this part of the nervous system. Psychiatric conditions are also problems of the CNS.

The PNS also consists of two parts – the somatic nervous system and the autonomic nervous system. The somatic nervous system includes the motor nerves (the nerves that cause movement) and the sensory nerves (the nerves that carry most sensations). This is the part of the nervous system you control consciously all the time.

The autonomic nervous system includes the sympathetic and parasympathetic nerves. As their name implies, these nerves control all the automatic functions of the body. You do not need to remember to beat your heart, digest your food, breathe, sweat, etc. The autonomic nervous system does this in the background. This part of the peripheral nervous system is only controllable indirectly.

Peripheral neuropathies, radiculopathies, and plexopathies are some conditions that can affect either the somatic, autonomic, or both nervous systems. There are also many medical conditions, such as diabetes, peripheral artery disease, infections, and malnutrition that can affect these nerves.

Conditions of the PNS can cause many problems including dysesthesias (painful or unpleasant sensations), paresthesias (abnormal sensations), numbness or sensory loss, and muscle weakness. They can also cause syncope (loss of consciousness), incontinence (loss of control of the bladder or rectum), digestive problems, and sexual dysfunction among other things.

Treatment includes systemic medications administered orally, intravenously, or even intrathecally (within the CNS), nerve blocks, and neurostimulation.