The Nervous System. ussystem
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Transcript of The Nervous System. ussystem
The Nervous System
http://www.brainpop.com/health/nervoussystem/nervoussystem/
The basic component of the nervous system is a neuron.
Neuron-conducting cells that constitute the brain, spinal column, and nerves, consisting of a nucleated cell body with one or more dendrites and a single axon. Also called nerve cell.
Neurons have 3 basic parts to themCell Body [soma]AxonDendrites
http://www.brainpop.com/health/nervoussystem/neurons/
The nervous system has two basic functions.
It gathers information It interprets information
This information comes from inside the body and from the world outside the body. The nervous system responds to this information as needed.
The way your body interacts with the world is through :
Stimulus Response
Stimulus-something that excites or causes a physical response in an organism.
Response-A reaction to a specific stimulus.
The Brain
http://www.brainpop.com/health/nervoussystem/brain/
The Brain
The nervous system has two parts.
Central nervous systemPeripheral nervous system
The Central Nervous System
Central or CNS- Consists of the brain and spinal cord
SpinalCord
Brain
Peripheral- nerves connecting CNS to muscles and organs
Central Nervous System
Peripheral Nervous System
The CNS processes and responds to all of the messages coming form the peripheral nervous system. Normally, information is transferred from the PNS to the CNS and Back. However, in some cases the PNS causes a response without involving the CNS.
PNS
The PNS has two types of nerves: Somatic and Autonomic nerves.
Somatic-control conscious movement.
Autonomic-control involuntary movements.
Autonomic System
Two divisions: sympathetic Parasympatheitic
Control involuntary functions heartbeat blood pressure respiration perspiration digestion
Can be influenced by thought and emotion
The brain can be divided into 3 regions
medullaCerebellumCerebrum
Cerebrum -is the thinking part of the brain and it controls your voluntary muscles.
Cerebellum -It controls balance, movement, and coordination (how your muscles work together).
Medulla -is to control your involuntary muscles the ones that work automatically, without you even thinking about it, also sorts through the millions of messages that the brain and the rest of the body send back and forth.
Peripheral Nervous System
2 kinds of neurons connect CNS to the body sensory motor
SpinalCord
Brain
Nerves
Motor - CNS to muscles and organs: a nerve cell neuron that sends nerve impulses from the spinal cord or brainstem away from the central nervous system toward a muscle or gland
Sensory - sends nerve impulses from the sense organs (sensory receptors) to the CNS.
Muscle
MotorNeuron
Interneuron
Skin receptors
SensoryNeuron
Brain
The senses provide information about the outside environment to the nervous system.
There are five senses:
SightTouchHearingTasteSmell
5 senses
The senses of sight, touch and hearing involve processing physical information from the environment.
The senses of smell and taste involve processing chemical information.
5 senses
Let’s look each one and explore the nerve responsible for helping navigate our world.
Optic nerve
Optic nerve- the second pair of cranial nerves whose nerve fibers transmit visual light signals from the eye to the brain.
http://www.brainpop.com/health/senses/eyes/
Auditory nerve
Auditory nerve-nerve connecting inner ear to brain: a nerve that conveys impulses relating to hearing and balance from the inner ear to the brain
Olfactory nerve
Olfactory nerve- nerves consisting of sensory fibers that conduct to the brain the impulses from the mucous membranes of the nose.
taste
Taste buds-Oval-shaped clusters of cells located on the tongue and lining of the mouth that contain special nerve endings that help give rise to the sense of taste.
http://www.brainpop.com/health/senses/taste/
skin
Is made up of different layers. Let’s look at 2 of them.
DermisEpidermis
Dermis
Dermis -the dense inner layer of skin beneath the epidermis, composed of connective tissue, blood and lymph vessels, sweat glands, hair follicles, and an elaborate sensory nerve network.
Epidermis
Epidermis-the outer layer of the skin covering the exterior body surface of vertebrates.
Light to Dark
There are many different skin tones. From the very light to the very dark. Let’s look at what causes us to have different skin color.
Melanin
Melanin-Insoluble naturally occurring dark pigments found in skin, hair, fur, and feathers. Responsible for the color of your skin.
Melanin protects the body by absorbing ultraviolet radiation from the sun.
The End