STUDY JAMS:
http://studyjams.scholastic.com/studyjams/jams/science/human-body/nervous-system.htm Nervous System •A pathway in which your brain sends and receives information about what is happening in and around the body •Main organs are the brain, spinal cord, and nerves (made up of nerve cells or neurons) •Consists of two systems: 1.Central Nervous System 2.Peripheral Nervous System Central Nervous System •Made up of the brain and spinal cord •The brain is protected by the skull. •The brain controls all body functions by sending and receiving messages up and down the spinal cord through the nerves. Peripheral Nervous System •Carries messages to and from parts of the body to the central nervous system through nerves •Carries out orders from the brain •Made up of two systems: 1.Somatic Nervous System 2.Autonomic Nervous System Somatic Nervous System •Sends information through peripheral nerves to your central nervous system •These messages are coming from all your senses. •Sends messages back to the senses in order to respond •Example: putting your hand on something hot and causing it to pull away Autonomic Nervous System •Makes sure processes in your body work automatically •You don’t have to think about these things. 1.Breathing 2.Digesting 3.Heart beating Brain •Part of the central nervous system •Soft spongy mass of nerve cells and supportive tissue •3 main parts that work together but have special functions 1.Cerebrum (red, green, yellow, blue) 2.Cerebellum (purple) 3.Brain Stem (gray) Cerebrum •Largest part of the brain •Uses information from our senses to tell us what is going on and how to respond •Divided into four lobes – 1. Frontal – reasoning, planning 2. Parietal –movement, balance 3. Occipital – visual processing 4. Temporal – auditory, memory Brainstem •Connects brain to spinal cord •Controls hunger and thirst •Also, the most basic body functions, such as body temperature, blood pressure and breathing Spinal Cord •Important structure between the brain and the body •40-50cm long, 1-1.5cm wide •Forms 31 pairs of spinal nerves •Contains motor and sensory nerve fibers sending information to and from all parts of the body Neurons (Nerve Cells) •Specialized cells that carry messages through an electrochemical process •Brain has 100 billion neurons •Messages are carried to and from the central and peripheral nervous systems through nerves (a bundle of neurons). Anatomy of a Neuron •Soma or cell body •Dendrites – brings electrical signals towards the soma •Axon – takes information away from the soma •Myelin Sheath - covers the axon and works like an insulator to keep the signal inside the cell Synapse •A gap that separates the axon of one neuron and the dendrite of the next neuron •The message carried by neurons is called a nerve impulse. •Neurons communicate through an electrochemical process. Sensory Neuron (A) •Nerve that carries impulses to the brain or spinal cord to a muscle or gland Interneuron (B) •Connector Motor Neuron (C) •A nerve that carries impulses from the brain or spinal cord to a muscle or gland Reflex •An involuntary response to something, which happens quickly •Protects your body from harm, like putting your hand on a hot stove •Sneezing and blinking •The doctor might check your knee jerk reaction for reflex health. Neurological Disorders •Multiple sclerosis •Alzheimer’s disease •Parkinson’s disease •Epilepsy •Stroke •Dementia •Head Trauma All can affect memory and ability to perform daily activities. Comments are closed.
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Erik E. Mason
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