Nervous System: Interactive Views and Information | Anatomy Guide
[Continued from above] . . . conditions inside and outside of the body and send this information to the CNS. Efferent nerves in the PNS carry signals from the control center to the muscles, glands, and organs to regulate their functions. Nervous TissueThe majority of the nervous system is tissue made up of two classes of cells: neurons and neuroglia. Neurons. Neurons, also known as nerve cells, communicate within the body by transmitting electrochemical signals. Brain The brain, a soft, wrinkled organ that weighs about 3 pounds, is located inside the cranial cavity, where the bones of the skull surround and protect it. Spinal CordThe spinal cord is a long, thin mass of bundled neurons that carries information through the vertebral cavity of the spine beginning at the medulla oblongata of the brain on its superior end and continuing inferiorly to the lumbar region of the spine. Afferent, Efferent, and Mixed Nerves. Dura mater. Sensory. Divisions of the Nervous System Sympathetic.
cells of the nervous system
Types of Neurons (Nerve Cells) The human body is made up of trillions of cells. Cells of the nervous system, called nerve cells or neurons, are specialized to carry "messages" through an electrochemical process. Neurons come in many different shapes and sizes. Neurons are similar to other cells in the body because: Neurons are surrounded by a cell membrane.Neurons have a nucleus that contains genes.Neurons contain cytoplasm, mitochondria and other organelles.Neurons carry out basic cellular processes such as protein synthesis and energy production. However, neurons differ from other cells in the body because: Neurons have specialize cell parts called dendrites and axons. The Neuron One way to classify neurons is by the number of extensions that extend from the neuron's cell body (soma). Bipolar neurons have two processes extending from the cell body (examples: retinal cells, olfactory epithelium cells). Pseudounipolar cells (example: dorsal root ganglion cells). What is inside of a neuron?
Enrichment: Activity
Discussion: The more frequently we are called on to do a certain task, the easier the task becomes. This is because our brain learns by doing. Each time we repeat a task, nerve cell connections in our brains are strengthened. This means that the brain doesn't have to figure out a problem from the beginning each time because it has already learned how to get to the answer. Materials: jigsaw puzzle of no more than 12 pieces (preferably one new to the class) clock with second hand Procedure: Time a volunteer doing the jigsaw puzzle and record the score on the board. How are the person's times different?
Explore the Brain
Advertisement. EnchantedLearning.com is a user-supported site. As a bonus, site members have access to a banner-ad-free version of the site, with print-friendly pages.Click here to learn more. (Already a member? THE FUNCTIONS OF THE BRAIN The human brain is a complex organ that allows us to think, move, feel, see, hear, taste, and smell. The brain produces electrical signals, which, together with chemical reactions, let the parts of the body communicate. The average human brain weighs about 3 pounds (1300-1400 g). At birth, the human brain weighs less than a pound (0.78-0.88 pounds or 350-400 g). The brain consists of gray matter (40%) and white matter (60%) contained within the skull. The brain has three main parts: the cerebrum, the cerebellum, and the brain stem (medulla). NOURISHMENT OF THE BRAIN Although the brain is only 2% of the body's weight, it uses 20% of the oxygen supply and gets 20% of the blood flow. Cerebrospinal fluid (CSF) surrounds the brain.
Your Lungs & Respiratory System
Listen Time for Talk Your lungs are important for breathing . . . and also for talking! Above the trachea (windpipe) is the larynx (say: LAIR-inks), which is sometimes called the voice box. The amount of air you blow out from your lungs determines how loud a sound will be and how long you can make the sound. Experiment with different sounds and the air it takes to make them — when you giggle, you let out your breath in short bits, but when you burp, you let swallowed air in your stomach out in one long one! Love Your Lungs Your lungs are amazing. Keeping your lungs looking and feeling healthy is a smart idea, and the best way to keep your lungs pink and healthy is not to smoke. Finally, cigarette smoke can damage the cells of the lungs so much that the healthy cells go away, only to be replaced by cancer cells. You can also show your love for your lungs by exercising! Reviewed by: Yamini Durani, MD Date reviewed: October 2012 Originally reviewed by: Laura Inselman, MD
The Constitution for Kids (4th-7th Grade)
This file is intended for students in grades 4 through 7. Other versions of this page are available: Want to change this page's colors? Choose a new skin! If you have any questions about any words or ideas on this page, please ask your parents or teachers for help. If there is anything that could be improved on this page, please let the Webmaster know! The Basics The Constitution is the highest law in the United States. The Constitution can be changed. History The Constitution was written in 1787. From May to September 1787 a group of men known as the Framers met. At that time there were only 13 states. After the Convention, the Constitution had to be approved. Amendments When the Constitution was written, the Framers knew their creation was not perfect. The Framers added an amendment process. Originally, some people did not want to ratify the Constitution. Soon, the new government started meeting. Other changes to the Constitution are discussed below. Slavery Women The Bill of Rights
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