Nervous System 6th Grade Health Mr. Springer

Nervous System Fast Facts The brain weighs about 3 pounds Gross Picture Alert!

Nervous System Fast Facts The brain contains about 10 billion cells that regulate: Your conscious acts Ex. Walking, talking, playing the piano Your involuntary functions Ex. Coughing, blinking, swallowing, breathing And your emotions Ex. Love, anger

Nervous System Fast Facts The nervous system requires oxygen to do it’s work. Ex. 15 seconds without oxygen will cause us to lose consciousness Ex. 4 minutes without oxygen will cause irreparable damage to the brain and even death

Nervous System Fast Facts The smallest neuron in the body is .004mm. The longest neuron in the body runs from the spinal cord to the big toe, and is over 1 meter long!

The Job Of The Nervous System Sends and interprets “messages” Allows the entire body, inside and out, to work together

Neurons (Nerve Cell)- specialized cells that carry information from the brain to the body and from the body to the brain The Cell body that houses the nucleus is known as the Soma. The finger-like projections at the base of the neuron are part of the axon and form the connections with dendrites or the part of the body being affected by the PNS.

Synapse: The location where one neuron meets with another cell (neuron, muscle, vein, etc.) and an electrical current is exchanged. This is how messages are sent from one neuron to the next, or from the end of the neuron (axon) to the muscle, or part of body that is being innervated (acted upon). Terminal buttons are at the base of the axon, and they form the connections. Think of a bus terminal, where you pay a fee to pass go. In the nervous system, a synapse is a junction that permits a neuron to pass an electrical or chemical signal to another cell. At a synapse, the plasma membrane of the signal-passing neuron (the presynaptic neuron) comes into close apposition with the membrane of the target (postsynaptic) cell. Both the presynaptic and postsynaptic sites contain extensive arrays of molecular machinery that link the two membranes together and carry out the signaling process. In many synapses, the presynaptic part is located on an axon, but some presynaptic sites are located on a dendrite or soma. There are two fundamentally different types of synapse:

Microscope images of nerves! Real life Microscope images of nerves!

Vocabulary Central Nervous System- includes the brain and spinal cord, it’s the body’s main control center Vertebrae protect the spinal cord. Vertebrae are part of the skeletal system.

Vocabulary Peripheral Nervous System- includes the nerves that connect the CNS to all parts of the body

Sensory Nerves & Motor Nerves You have two types of nerves: Sensory- carries messages from the sense receptors to the brain and spinal cord Motor- carries messages from the brain to the muscles, glands, and other body structures, resulting in actions So when you feel pain (such as in your finger tips) sense receptors in your skin send a message to your brain. The message starts in the neurons of your PNS and travels up to the CNS (spine and brain), where your brain translates the message and tells your body (you become conscious of the pain).

Parts Of The Brain Cerebrum- it’s the largest part of the brain, it controls your ability to think, memorize, and learn. It also receives messages for your senses (sight, hearing, smell, touch, and taste) Cerebellum- it controls balance, posture, and coordination. Medulla- it controls your involuntary muscle actions such as breathing. http://www.apparelyzed.com/broken-neck.html : This link describes the differences in fractures at certain spots in the Cervical spine (upper 7 vertebrae)… Remember the Lower 5 vertebrae are the lumbar, and the center 12 vertebrae are the thoracic vertebrae.

Cerebrum Cerebellum Medulla The medulla is part of your spinal cord. That is why, if you break your neck, you may damage this part of your brain. If this part of your brain is damaged (as a result of a high neck break) the result is death because organs shut down! Medulla

Problems With The Nervous System MS (Multiple Sclerosis)- degenerative disease in which the protective outer coating of nerves is damaged, thus the nerves no longer work properly Problems with thinking and memory 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. Symptoms Signs and symptoms of multiple sclerosis vary widely, depending on the location of affected nerve fibers. Multiple sclerosis signs and symptoms may include: Numbness or weakness in one or more limbs, which typically occurs on one side of your body at a time or the bottom half of your body Partial or complete loss of vision, usually in one eye at a time, often with pain during eye movement (optic neuritis) Double vision or blurring of vision Tingling or pain in parts of your body Electric-shock sensations that occur with certain head movements Tremor, lack of coordination or unsteady gait Fatigue Dizziness

Problems With The Nervous System Parkinson’s – Shaking and stiffness of the arms and legs. Epilepsy – Seizures, as a result of abnormal electrical activity in brain. Alzheimer’s – affects mostly older people, it is inflamed areas in the brain and death of neurons (atrophy). Leads to memory loss and dementia

Neck/Spine Injuries Can lead to paralysis (loss of feeling and mobility in parts of the body) FACT: The medulla is part of your spinal cord. If you break your neck, you may damage this part of your brain. If this part of your brain is damaged the result can be death because your organs shut down!

Brain Diagram Without Labels

Brain Diagram (W/Labels) http://www.edhelper.com/teachers/health_Brain_with_Labels.htm

Nervous System Diagram(W/O Labels) http://www.edhelper.com/teachers/health_Nervous_System.htm

Nervous System Diagram (W/Labels) http://www.edhelper.com/teachers/health_Nervous_System_with_Labels.htm

Review At this website, we will connect nerves from different body parts to the section of the spinal cord they connect to. Notice the parts of the brain that light up. (That section of the brain controls the body part) Click Here>>>>>> (other) Brain Games>>>>