The Nervous System Miss Charney Northville Central School Miss Charney Northville Central School

Nervous System Functions F Receives information about what is happening to your body F Stimulus - change or signal that makes the body react F Directs the way in which your body responds to the information F Response - what your body does in a reaction F Receives information about what is happening to your body F Stimulus - change or signal that makes the body react F Directs the way in which your body responds to the information F Response - what your body does in a reaction

Neurons F Cells that carry information through your nervous system F Nucleus - directs the actions of the neuron F Dendrites - carry impulses toward the neuron’s cell body (can have many) F Axon - carries impulses away from the cell body (can have only one) F Cells that carry information through your nervous system F Nucleus - directs the actions of the neuron F Dendrites - carry impulses toward the neuron’s cell body (can have many) F Axon - carries impulses away from the cell body (can have only one)

Types of Neurons F Motor Neuron: sends impulses to a muscle or gland F Sensory Neuron: picks up stimuli from the internal or external environment and converts the stimulus into a nerve impulse F Motor Neuron: sends impulses to a muscle or gland F Sensory Neuron: picks up stimuli from the internal or external environment and converts the stimulus into a nerve impulse

How An Impulse Travels F Synapse: the junction where one neuron can transfer an impulse to another

How An Impulse Travels

1. Nerve impulses begin when receptors pick up stimuli from the environment 2. Receptors trigger nerve impulses in sensory neurons 3. Nerve impulses pass to interneurons in the brain 4. Your brain interprets the impulses 5. Impulses travel along thousands of motor neurons 6. Motor neurons send the impulses to muscles, which carry out the response 1. Nerve impulses begin when receptors pick up stimuli from the environment 2. Receptors trigger nerve impulses in sensory neurons 3. Nerve impulses pass to interneurons in the brain 4. Your brain interprets the impulses 5. Impulses travel along thousands of motor neurons 6. Motor neurons send the impulses to muscles, which carry out the response

Parts of the Nervous System

Central Nervous System F Control center of the body F Brain: located in the skull, is the part of the CNS that controls most functions in the body F Spinal Cord: thick column of nervous tissue the links the brain to most of the nerves in the peripheral nervous system F Control center of the body F Brain: located in the skull, is the part of the CNS that controls most functions in the body F Spinal Cord: thick column of nervous tissue the links the brain to most of the nerves in the peripheral nervous system

Parts of the Brain F Cerebrum: largest part of the brain F Interprets input from the senses, controls movement, and carries out complex mental processes such as learning and remembering F Left half - mathematical skills & logical thinking F Right half - creativity & artistic ability F Cerebrum: largest part of the brain F Interprets input from the senses, controls movement, and carries out complex mental processes such as learning and remembering F Left half - mathematical skills & logical thinking F Right half - creativity & artistic ability

Parts of the Brain F Cerebellum: second largest part of the brain F Coordinates actions of your muscles and helps you to keep balance F Cerebellum: second largest part of the brain F Coordinates actions of your muscles and helps you to keep balance

Parts of the Brain F Brain Stem: between the cerebellum and the spinal cord F Controls your body’s involuntary actions such as breathing and heart rate F Brain Stem: between the cerebellum and the spinal cord F Controls your body’s involuntary actions such as breathing and heart rate

Peripheral Nervous System F network of nerves branching out from the CNS and connect to body F Somatic Nervous System: control voluntary actions such as using a fork or tying your shoes F Automatic Nervous System: control involuntary actions F network of nerves branching out from the CNS and connect to body F Somatic Nervous System: control voluntary actions such as using a fork or tying your shoes F Automatic Nervous System: control involuntary actions

Reflexes F Automatic response that occurs very rapidly and without conscious control F Reflex Pathway: 1. Sensory neurons in your fingertip detect a pain stimulus 2. Nerve impulses travel to your spinal cord 3. Nerve impulses return to motor neurons in your hand, and you pull your hand away 4. As you pull your hand away, nerve impulses travel to your brain. You feel the pain F Automatic response that occurs very rapidly and without conscious control F Reflex Pathway: 1. Sensory neurons in your fingertip detect a pain stimulus 2. Nerve impulses travel to your spinal cord 3. Nerve impulses return to motor neurons in your hand, and you pull your hand away 4. As you pull your hand away, nerve impulses travel to your brain. You feel the pain