Chapter 7 The Human Body and the External World

The Nervous System

Write the WHITE Read the BLACK

WHAT DO YOU KNOW ABOUT THE NERVOUS SYSTEM?

Follow along on pg. 121 of workbook

the nervous system : Receives, processes, stores and transmits information (stimuli) from inside & outside of body

composed of the Central Nervous System (CNS)- brain and spinal cord and the Peripheral Nervous System (PNS)- nerves

What are the stimuli you would receive if this was you?

The Neuron a specialized nerve cell Receive and transmit information (info.).

Use pg. 203 of textbook to fill in the Anatomy of a Neuron on pg. 121 of workbook

Check your answers Dendrites Cell body Nucleus Axon Neuron Terminals

Neuron facts: transmits impulse from one neuron  to next until reaches target (e.g. brain or muscle) Like an electric current Consumes lots of O 2 (only last a few minutes without it) (why CPR is important) and glucose

Can live for more than 100 years (keep the same neurons your whole life-unless kill them with drugs) Cannot reproduce itself-not replaced if destroyed

= anything that can be perceived and then trigger a reaction Example: sun shining in your eyes = pupils close

Nerve impulse = an electrical signal transmitted by a neuron

Synapse = transition zone between 2 neurons (message passed to next nerve with chemicals)

Transmission of Impulses Dendrites = receive messages & change them to nerve impulses (travel at about 430 km/h) Nerve impulses transmitted along axons to terminals

Neurotransmitter released in synapse Impulse transmitted to next neuron

Nerve.mpg

Use pg. 204 of textbook to fill in the bottom of pg. 121 in workbook

Homework: pg. 122 of workbook

Peripheral Nervous System

 the PNS = connects CNS to different parts of the body  Has two types of nerves: sensory (in) and motor (out) nerves

Sensory Receptors Pick up stimuli = change to nerve impulses Specialized nerve cells e.g. Retina in eye

Sensory Nerves Transmit information via impulses from sensory receptors  CNS e.g. Optic nerve in eye

Motor nerves Transmit impulses from CNS to muscles or glands muscles = voluntary (pick up an object) or involuntary (pupils contract in bright light)

Did you know? Acupuncture has been practiced for 7000 years originating in China. Channels of energy run in regular patterns through the body. An obstruction in the movement of these energy rivers is like a dam that backs up the flow in one part of the body and restricts it in others. The acupuncture needles unblock the obstruction at the dams, and re- establish the regular flow.

Modern science explains this as: Needling the acupuncture points stimulates the nervous system to release chemicals in the muscles, spinal cord, and brain. These chemicals will either change the experience of pain, or they will trigger the release of other chemicals and hormones which influence the body’s own internal regulating system.

Kung fu panda

Use pg. 205 of textbook to fill in pg. 123 of workbook

Homework: pg. 124 of workbook, q 1-3

The Central Nervous System

The Central Nervous System =coordinates a major part of the nervous system

Composed of the parts of the CNS location in the cranium (skull) A large mass of nerve cells (more than 100 billion neurons) There are rare exceptions!!! The Brain

Here we have a case of “ Brainus peanutii minimalis”

Use pg. 207 of textbook to label the diagram on pg. 125 of the workbook

Brain model

The control central of voluntary movement, intelligence, and sensory interpretation Is the center of emotion and regulating body functions The Cerebrum

Outer =grey matter (cerebral cortex)= higher brain functions (plan, reason, logic) inner= white matter (myelin sheath of nerves)

RT/LT brain test

control center for balance and coordination The Cerebellum

controls involuntary movement as well as internal stimuli e.g. heartbeat, breathing, and blood pressure. The Brain Stem

 A nervous system organ that sends messages to & from brain.  Processes reflexes The Spinal Cord

Fill into pg. 126 top, of workbook meninges

31 pairs of nerves attached to spinal cord spinal cord = protected by small bones called vertebrae

Spinal cord model

Lab 62- Dissect brain (if Nancy can get them)

Reflex Rapid, involuntary reaction to a stimulus Involves sensory nerves, spinal cord, and motor nerves Brain only receives info. AFTER the reaction has occurred

Reflex arc The path taken by the nerve impulse during a reflex

Sensory Receptor (responds to a stimulus by producing a impulse) Sensory Neuron (axon conducts impulse) Integrating Center (Relay impulse from sensory to motor neurons) Motor Neuron (axon conducts impulse to effector) Effector (muscle that responds to a motor nerve impulse) Reflex Arc

Use pg of textbook to fill in pg. 126 of workbook

Lab 63- Reflexes

Discuss: pg. 229 of textbook Q 1-8

Homework: pg of workbook

Crash course Nervous system