Salutations. Glad you're here. In this lecture, we will begin our exploration of medical terminology as it relates to the nervous system. Let's get started. Don't be nervous, it's going to be fine. Our knowledge perception and response to the world around us are all due to the nervous system. The nervous system also coordinates the activities of the body. It receives sensory information from both inside and outside of the body, and then interprets the information and decides what to do with it. Fun fact, the fastest signal transmission in the body occurs in the alpha motor neurons within the spinal cord. They transmit a signal at 268 miles per hour. The slowest signal transmission is within the skin, at one mile per hour. Let's begin by looking at the basic purposes and anatomy of the nervous system. But first, let's look at this adorable baby sea lion. One primary purpose of the nervous system is to coordinate the body systems and allow them to communicate with each other for a common goal, like this telephone switchboard. The sensory system, like our eyes, ears, nose, and skin, detects information from the outside environment and sends it to the brain via nerves. Nerves can be thought of as wires that connect the sensory organs to the brain. The brain makes sense of the information and determines what it will do with the information. This action plan is then sent out to the other organ systems via nerves. The branch of medicine that deals with the nerves and organs of the nervous system is neurology. The nervous system is also involved in how we behave and respond to the environment around us. When an event happens to us, we react with our emotions and express our opinions and beliefs. Most of us have many feels, however, my husband hates talking about feelings and says he only has two: hungry and sleepy. There are two different medical specialties that deal with problems in our perceptions, emotions, and behavior: psychiatry and psychology. The nervous system is divided into two parts: the central and peripheral nervous systems. The central nervous system is made up of the brain and the spinal cord. The peripheral nervous system is made up of the nerves that send information to and from the central nervous system. There are two main divisions of action : voluntary and involuntary. Recall that the central nervous system is made up of the brain and spinal cord. We will look at new word roots pertaining to the central nervous system next. The cerebrum is what we traditionally call the brain, and is sectioned into lobes. The cerebrum can also be divided into left and right hemispheres. There are multiple word roots that all mean brain, they include cerebral and encephalo. You can see them in words like cerebrospinal and encephalitis. The cerebrum can be further subdivided into lobes or specialized areas of the brain. The word root for lobe is lobo. Lobo is also Spanish for wolf, totally unrelated. You're welcome. The cerebellum is at the base of the cerebrum and controls things like coordination of movements. I like to say that the cerebrum allows you to walk, but the cerebellum allows you to dance. Cerebello is our root that means cerebellum, and can be seen in the word cerebellar, which means pertaining to the cerebellum. Fun fact, although it only accounts for about 10 percent of the brain's volume, the cerebellum contains over 50 percent of all of the brain's neurons. There are two word roots for head: cephalo, and cranio. Cranio can also be used to mean skull as shown here. You can see them in the words microcephaly and cranial orthosis. The opposite of microcephaly is macrocephaly, which is what happened to your ex when they got discovered by that talent agency. So far, we have roots for the brain portion of the CNS, but not the spinal cord. Not fair. Don't worry, we're now making it right. Myelo means spinal cord. There, now everyone has been acknowledged. I mentioned earlier that a specialist in the nervous system is called a neurologist. The root, neuro, is pretty common and means nerve. A group of nerve cell bodies or a nerve bundle is called a ganglia, used in the other root seen here, ganglio. Now for a 10-second brain break. In the previous section, we focused on neurology word roots. The following section, we'll focus on the psyche, which is Greek for mind. Our first word roots related to the psyche are phreno and psycho, which both mean mind. Phreno can be seen in Schizophrenia, and Psycho in the term psychic or psychology. The root esthesio means feeling or sensation. I'm sure you've heard this one used in terms like anesthesia, which is, of course, a drug that creates a lack of sensation as in during a surgical procedure. They also use anesthesia for dental procedures that allow the patient to remain conscious. Sleep has three-word roots: somno, somnio, and hypno. You've probably seen them in words like insomnia or the inability to sleep, and hypnosis, which is a condition of sleep. Meaning knowledge, gnosio has already been used quite a bit in the course and I bet you didn't even acknowledge it. Acknowledge it because gnosio means knowledge. We use it every time we say the word diagnosis. Although the focus has been on new word roots, there are also some suffixes specific to the psyche. Our first suffix is phobia, which means an excessive fear or sensitivity. It can be seen in botanophobia or a fear of plants, and ombrophobia or a fear of rain. Another suffix related to the psyche is mania or an excessive desire. Other manias include kleptomania and, the buzzword around my house, pyromania Don't worry, we have four fire extinguishers seriously and we know they fired you. Finally, these suffixes are also commonly used in neurology. Paresis means a slight or partial paralysis. Plegia means paralysis, and can be seen in the word hemiplegia or paralysis of one side of the body. Asthenia means weakness as seen in myasthenia gravis, which is a weakening of the skeletal muscles, particularly in the face. As with all good things, this lecture too must come to an end. Thanks for exploring introductory terms and roots related to the nervous system with me. See you next time.
