As the brain grows in the developing fetus, new neurons are created at the rate of 250,000 per minuteThe adult brain has 100 billion neurons and weighs about 3 pounds (2% body weight)Average number of neurons in an octopus brain: 300 millionA nerve impulse travels about 300 mphYou cannot tickle yourself. You can’t trick the cerebellum, it knows when you are attempting to tickle yourselfThere are more nerve cells in the human brain than there are stars in the Milky WayThe Greeks thought the heart was the location of intelligence and thought.The Egyptians didn’t think much of the brain either, it was scrambled and sucked out brains through the nostrils and threw them away.
Nerv/o or neur/o nerveCrani/o craniumCerebr/o cerebrum (largest part of brain)Cortic/o cortex (outer regions)Somat/o bodyGustat/o sense of tasteTempor/o temple (side of head)Audit/o sense of hearingOlfact/o sense of smellingOccipit/oocciput (back of head)Thalam/o thalamusSpin/o spineCerebell/o cerebellum (posterior part of brain)Meningi/o meninges line the brain and spinal cordDur/o dura materCyt/o cellVag/o wandering (vagus nerve)Gloss/o tongueOpt/o eye, visionVentricul/o ventricle (lower chambers in heart, chamber in brain)Myel/o spinal cordHemi- one halfHyper- above, more than normalEpi- upon, abovePara- beside, apart from, 2 parts of a pair, abnormalAffer/o bring toward centerEffer/o go out from center
The nervous system of the human being is responsible for sending, receiving, and processing nerve impulses throughout the body. All the organs and muscles inside your body rely upon these nerve impulses to function. It could be considered as the master control unit inside your body. Sense organs provide the nervous system with information about the environment by means of such senses as sight, hearing, smell, taste, tough, pressure, and pain. Nerves are connected throughout the whole body to the brain. They carry the information throughout the body in the form of electrochemical signals called impulses. These impulses travel from the brain and spinal cord to the nerves located throughout the body. For example, if we touch something, impulses travel through the nerve network to the brain at a rate of 350 feet per second. It is largely made up of specialized cells called neurons. Each of these neuron has a cell body, or cyton, which contains the nucleus and organelles. It takes the corporation of three system to carry out the mission of the nervous system . They are the central, the peripheral, and the autonomic nervous systems. The central nervous system has the responsibility for issuing nerve impulses and analyzing sensory data, and includes the brain and spinal cord. The peripheral nervous system is responsible for carrying these nerve impulses to and from the body. The autonomic nervous system is composed of the sympathetic and parasympathetic systems and is responsible for regulating and coordinating the functions of vital structures in the body.
Acetylcholine has many functions: It is responsible for much of the stimulation of muscles, including the muscles of the gastro-intestinal system. It is also found in sensory neurons and in the autonomic nervous system, and has a part in scheduling REM (dream) sleep. Dopamine is an inhibitory neurotransmitter, meaning that when it finds its way to its receptor sites, it blocks the tendency of that neuron to fire. Dopamine is strongly associated with reward mechanisms in the brain. Drugs like cocaine, opium, heroin, and alcohol increase the levels of dopamine, as does nicotine. If it feels good, dopamine neurons are probably involved! Endorphin Endorphin is short for "endogenous morphine." It is structurally very similar to the opioids (opium, morphine, heroin, etc.) and has similar functions: Inhibitory, it is involved in pain reduction and pleasure, and the opioid drugs work by attaching to endorphin's receptor sites. It is also the neurotransmitter that allows bears and other animals to hibernate.Epinephrine Adrenaline. Fight or flight. Epinephrine is an excitatory neurotransmitter, that is derived from norepinephrine. Epinephrine controls mental focus and attention.Norepinephrineis strongly associated with bringing our nervous systems into "high alert." It is prevalent in the sympathetic nervous system, and it increases our heart rate and our blood pressure. Our adrenal glands release it into the blood stream. It is also important for forming memories.Stress tends to deplete our store of adrenalin, while exercise tends to increase it. Serotonin is an inhibitory neurotransmitter that has been found to be intimately involved in emotion and mood. Too little serotonin has been shown to lead to depression, problems with anger control, obsessive-compulsive disorder, and suicide. Prozac and other recent drugs help people with depression by preventing the neurons from "vacuuming" up excess seratonin, so that there is more left floating around in the synapses. It is interesting that a little warm milk before bedtime also increases the levels of seratonin. Serotonin is a derivative of tryptophan, which is found in milk. The "warm" part is just for comfort! GABA is also usually an inhibitory neurotransmitter. GABA acts like a brake to the excitatory neurotransmitters that lead to anxiety. People with too little GABA tend to suffer from anxiety disorders, and drugs like Valium work by enhancing the effects of GABA. Lots of other drugs influence GABA receptors, including alcohol and barbituates. If GABA is lacking in certain parts of the brain, epilepsy results.
CVA: often preceded by TIA, weakness and loss of sensation due to temporary lack of oxygenated blood to brain cells. Can be caused by clot or arteriosclerosis and result in death of brain cells. Can affect either side of the brain and resulting opposite side of the bodyConcussion: injury to brain that can cause loss of consciousness caused by shaking or jarring. Does not include hemorrhaging.Dementia: Dementia isn't a specific disease. Instead, it describes a group of symptoms affecting intellectual and social abilities severely enough to interfere with daily functioning. It's caused by conditions or changes in the brain. Different types of dementia exist, depending on the cause. Alzheimer's disease is the most common type. Memory loss generally occurs in dementia, but memory loss alone doesn't mean you have dementia. Dementia indicates problems with at least two brain functions, such as memory loss along with impaired judgment or language. Dementia can make you confused and unable to remember people and names. You may also experience changes in personality and social behavior. Epilepsy: Epilepsy is a disorder that results from the generation of electrical signals inside the brain, causing recurring seizures. Seizure symptoms vary. Some people with epilepsy simply stare blankly for a few seconds during a seizure, while others have full-fledged convulsions. About one in 100 people in the United States will experience an unprovoked seizure in their lifetime. However, a solitary seizure doesn't mean you have epilepsy. At least two unprovoked seizures are required for an epilepsy diagnosis. Even mild seizures may require treatment, because they can be dangerous during activities like driving or swimming. Treatment — which generally includes medications and sometimes surgery — usually eliminates or reduces the frequency and intensity of seizures. Many children with epilepsy even outgrow the condition with age. Meningitis: Meningitis is an inflammation of the membranes (meninges) and cerebrospinal fluid surrounding your brain and spinal cord, usually due to the spread of an infection. The swelling associated with meningitis often triggers the "hallmark" symptoms of this condition, including headache, fever and a stiff neck. Most cases of meningitis are caused by a viral infection, but bacterial and fungal infections also can lead to meningitis. Depending on the cause of the infection, meningitis can resolve on its own in a couple of weeks — or it can be a life-threatening emergency.Mutliple Sclerosis: Multiple sclerosis (MS) is a potentially debilitating disease in which your body's immune system eats away at the protective sheath that covers your nerves. This interferes with the communication between your brain and the rest of your body. Ultimately, this may result in deterioration of the nerves themselves, a process that's not reversible. Symptoms vary widely, depending on the amount of damage and which particular nerves are affected. People with severe cases of multiple sclerosis may lose the ability to walk or speak. Multiple sclerosis can be difficult to diagnose early in the course of the disease, because symptoms often come and go — sometimes disappearing for months. Although multiple sclerosis can occur at any age, it most often begins in people between the ages of 20 and 40. Women are more likely to develop multiple sclerosis than are men.Cerebral Palsy: is a general term for a group of disorders that appear during the first few years of life and affect a child's ability to coordinate body movements. Cerebral palsy can cause muscles to be weak and floppy, or rigid and stiff. Most cases of cerebral palsy are believed to be caused by problems that occur before the baby is born, although some cases have been linked to brain injuries or infections during the first few months or years of life. Doctors can't always determine the root cause of the brain damage that results in cerebral palsy. Potential causes include: Infections (rubella, varicella, cytomegalovirus,Toxoplasmosis, Syphilis.Infant illnesses that have been linked to cerebral palsy include: Meningitis. Viral encephalitis, Congenital abnormalities, Strokes, Lack of oxygen, Severe jaundice
