fi yuo cna raed tihs, yuo hvae a sgtrane mnid too Cna yuo raed tihs? i cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid, aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it dseno't mtaetr in waht oerdr the ltteres in a wrod are, the olny iproamtnt tihng is taht the frsit and lsat ltteer be in the rghit pclae. • The rset can be a taotl mses and you can sitll raed it whotuit a pboerlm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Azanmig huh? yaeh and I awlyas tghuhot slpeling was ipmorantt! Introduction to Health Science The Nervous System (Regulatory System) What is the nervous system composed of? • Brain • Spinal Cord • Nerves • Sense Organs • Receptors Fun facts first! What’s it made of? • 77% Water • 10-12% Lipids • 8% Protein • 1% Carbs • 2% Soluble Organics • 1% Inorganic Salt There are… • 100 Billion Neurons in the Human Brain About The same amount… • Of Stars in the Sky The left hemisphere has… • 186 million more neurons than the right hemisphere. 750-1000ml of blood flow… • through the brain every minute. • This is about 3 full soda cans! The brain can stay alive… • 4-6 minutes without oxygen! The slowest neurons in the brain… • travel at 260 MPH. • As “slow” as today’s fastest car! (Clocked at 253 MPH) More electrical impulses… • Are generated in one day by a single human brain than all the telephones in the world. The human brain has… • 70,000 thoughts in an average day. FUNCTIONS OF THE BRAIN (or noodle) The Basic Functions of the Nervous System • Sensation – The ability of the nerves to detect stimuli, such as pressure, temperature changes, taste, smell or light, and send a message in the form of impulses to the brain and spinal cord. Integration • The nervous system receives and interprets sensory stimuli from the body and determines an appropriate response to those stimuli. Movement • The ability of the brain to send impulses through motor nerves to muscles and glands to cause movement or secretion of hormones. Left vs. right • Logical • Creativity • Mathematical • Imagination • Linguistic • Speech • Artists • Dreamers • Visual Spatial The Brain • The brain is responsible for analyzing information, processing information and relaying messages to the rest of the body. It is the main control center of the body. • Along with the spinal cord, it forms the body’s Central Nervous System or CNS. • The brain is composed of three main parts: – Cerebrum – Cerebellum – Brain Stem Brain Structures and Functions • Cerebrum – The cerebrum is the largest part of the brain. It has two distinct halves called hemispheres. The cerebrum has many folds and grooves to increase the number of nerves found in the brain. • The cerebrum is divided into four lobes. – – – – Frontal Lobe Parietal Lobe Temporal Lobe Occipital Lobe The Basic Structures of the Nervous System • Frontal Lobe – The frontal lobe controls skeletal muscle movement, interprets the sense of smell, is responsible for our personalities, and our ability to learn, think, problem solve and concentrate. • Parietal Lobe – The parietal lobe interprets many of our senses including taste, touch, temperature, and pain. • Occipital Lobe – The occipital lobe interprets the sense of sight. • Temporal Lobe – The temporal lobe interprets the senses of balance and hearing. It also contains structures (such as the hippocampus) which store memory. Cerebellum • The cerebellum is the second largest part of the brain. In fact, cerebellum means the “little cerebrum.” It is located at the back of the head below the cerebrum. • It functions to coordinate the muscular movements and helps the muscles move gracefully and efficiently. It also helps with the body’s ability to balance. Brainstem • The brain stem is located below the cerebellum and connects the spinal cord to the brain. • The brain stem is composed of two structures – the medulla oblongata and the pons. – The medulla oblongata is continuous with the spinal cord and helps to regulate the heart beat, blood pressure, breathing, swallowing, hiccupping, and vomiting. It also relays nerve impulses between the brain and the spinal cord. – The pons is a small bulge above the medulla oblongata. It is important to help us regulate the rate and depth of breathing. How does the brain communicate with the rest of the body? The Spinal Cord • Along with the brain, it is part of the Central Nervous System. • It is the major communication link between the brain and the rest of the body. • It can process many reflexes – unconscious, automatic responses to stimuli. • There are 31 pairs of spinal nerves which branch from the spinal cord to control such processes as breathing, arm movement, and leg movement. Cerebrospinal Fluid • CSF is a clear, watery fluid which bathes the brain and the spinal cord to protect it by acting as a shock absorber. • CSF allows for the exchange of nutrients and waste products between the blood and the nervous tissue. • CSF circulates between the two layers of the meninges, through the center of the spinal cord, and through large openings in the brain (ventricles). Meninges • A set of three layers of connective tissue that enclose the brain and spinal cord. They are located under the skull and attach directly to the brain. • Meninges help to provide a small amount of protection to the brain and spinal cord. • Cerebrospinal fluid circulates between two layer of the meninges. neurons Nerves • Nerves (neurons) are the basic units of structure and function for the nervous system. • Nerves are capable of sending electrical messages called impulses. • There are two main types of nerves: – Sensory nerves – Motor nerves Sensory Neurons • Specialized to detect changes and carry impulses to the brain and spinal cord from the sense organs. • Example: pressure or heat Motor neurons • detect changes and carry impulses away from the brain and spinal cord that signal muscle contractions… Nerve Structure • There are three basic parts of a neuron: – Dendrites • Short, branchlike extensions which conduct electrical signals toward the cell body. – Cell Body • Contains large nucleus and other cellular organelles. – Axon • Extends from the cell body. Responsible for carrying nerve impulses to other neurons, muscles or glands. CYK Please put your notes away and your thinking cap on. Rules: • Use your motor neurons (raise your hand) if you think you know the answer! • If you get it right then I will feed your sensory organs. Part of the nervous system that starts with a “B” #1 Name that Lobe interprets many of our senses #2 The spinal cord has how many paired spinal Nerves? #3 Name that Neuron: (Senses heat) #4 Part of the nervous system that starts with an “N” #5 Clear liquid that acts as a shock absorber to protect the brain #6 Name the part that connects the brain to the spinal cord #7 Known to as the “little cerebrum”: #8 Nervous System DISEASES AND DISORDERS Describe Diseases Disorders of the Nervous System • Meningitis – Meningitis is an infection that causes the inflammation of the brain and spinal cord coverings. Most common forms are bacterial or viral. – Symptoms: fever, chills, headache, nausea, vomiting, stiff neck – Treatment: Antibiotics for bacterial meningitis Epilepsy • Epilepsy is a brain disorder involving repeated seizures of any kind. Seizures are episodes of disturbed brain function that cause changes in attention or•behavior. Symptoms: • Loss of consciousness • Staring spells • Violent convulsions. • Treatment: • Varies depending on the cause. • May be controlled by medications. Concussion • Post traumatic impairment of neural function caused by a direct blow to the head resulting in bruising of the brain. – Symptoms may include headache, loss of consciousness, ringing of the ears, nausea, irritability, confusion, disorientation, dizziness, amnesia or difficulty concentrating. – Treatment may include removal from play, rest avoiding re-injury, medications for pain, physical therapy and relaxation. Stroke • Stroke, also known as a CVA or cerebrovascular accident, occurs when there is an interruption of the blood supply to any part of the brain. • Symptoms appear suddenly and can include weakness or paralysis of an extremity, numbness, vision changes, slurred speech, difficulty swallowing and loss of memory • It is important to get immediate care to reduce permanent complications. Physical therapy and/or occupational therapy may be needed.