Nervous System
Made By: Michaela D. Kailee R. Emma B. and Lillian D.
Nervous System
The nervous system is made up of the brain, the spinal cord, and nerves. One of the most important systems in your body, the nervous system is your body's control system. It sends, receives, and processes nerve impulses throughout the body. These nerve impulses tell your muscles and organs what to do and how to respond to the environment. There are three parts of your nervous system that work together: the central nervous system, the peripheral nervous system, and the autonomic nervous system.
The Central Nervous System
The central nervous system (CNS) consists of the brain and spinal cord. It sends out nerve impulses and analyzes information from the sense organs, which tell your brain about things you see, hear, smell, taste and feel.
The Peripheral Nervous System
The peripheral nervous system (PNS) includes the craniospinal nerves that branch off from the brain and the spinal cord. It carries the nerve impulses from the central nervous system to the muscles and glands. The somatic nervous system is the part of the peripheral nervous system[1] associated with the voluntary control of body movements via skeletal muscles.
The Autonomic Nervous System
The autonomic nervous system (ANS) regulates involuntary action, such as heart beat and digestion.
Structure and Control Centers of the Brain
The brain has three main parts, the cerebrum, the cerebellum, and the brain stem.
The Cerebrum or cortex is the largest part of the human brain, associated with higher brain function such as thought and action.
The Cerebellum receives information from the sensory systems, the spinal cord, and other parts of the brain and then regulates motor movements.The cerebellum coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth, balanced muscular activity.
The Brain Stem has many basic functions, including regulation of heart rate, breathing, sleeping, and eating.
Stroke
A disease of the nervous system is a stroke. A stroke occurs when the flow of blood to the brain is disrupted, which can happen when there's a blockage in one of the brain's blood vessels or when one of these blood vessels ruptures. Blood carries oxygen to the brain, which controls all of the body's functions. Without oxygen-rich blood, the brain begins to shut down.
Structure of a Neuron
Neuron
A typical neuron is divided into three parts: the cell body, the dendrites and the axon. The cell body (green color), the center of the neuron, extends its processes called the axon and the dendrites to other cells. Dendrites typically branch profusely, getting thinner with each branching (blue color). The axon is thin but can reach enormous distances (violet color).
How a Nerve Impulse Travels
Nerve impulses have a domino effect. Each neuron receives an impulse and must pass it on to the next neuron and make sure the correct impulse continues on its path. Through a chain of chemical events, the dendrites (part of a neuron) pick up an impulse that's shuttled through the axon and transmitted to the next neuron. The entire impulse passes through a neuron in about seven milliseconds.
Nervous System Citations
"Your Body's Systems." Your Body's Systems. Fact Monster, Oct. 2013. Web. 15 Dec. 2014.
"SEER Training Modules." SEER Training:Introduction to the Nervous System. US Department of Health & Human Services, n.d. Web. 15 Dec. 2014.