Activator
 Cell phones never work in horror movies. Imagine an attempt to
reduce cell phone use in class by the teacher locking the door and
pulling out all sorts of torture devices.That would be kind a crazy.
And then the teacher walks right up to you and asks…
 Which organs do you think are absolutely
necessary in order for you to keep living?
The Nervous System
Wait… WHAT IS HE DOING WITH THAT
MOUSE TRAP!
Today’s class will be Nerve Wracking
 The nervous system is used by your body for a lot of things.
 But before we can get to the system, we need to first
understand the individual unit. The neuron.
 Pg 962
Ask me about the synapse
Copy these notes
 There are three kinds of neurons:
Sensory neurons, interneurons, and motor neurons.
 The sensory neuron creates an impulse that travels to an
interneuron in the spine or brain.
 The interneuron then sends an impulse to a motor neuron.
 The motor neuron then signals its muscle to act.
 This whole pathway is called an Arc Reflex
Action Potential
Organization of the Nervous System
 There are two major divisions
 The Central Nervous System: (CNS) brain and spinal
cord
 The Peripheral Nervous System: (PNS) the sensory
neurons and motor neurons
 Responsible for transmitting electrical messages throughout
the body.
 Nerve: a bundle of several neuron axons
The Brain
 Over 100 billion neurons
 Cerebrum: the largest part of the
brain. Location of thought
processes.
 Cerebellum: controls balance,
posture, motor skills.
 Medulla oblongata: breathing and
heart rate.
 Hypothalampus: body tempurature,
thirst, hunger.
The peripheral nervous system
The somatic nervous
system
The autonomic nervous
system
 Voluntary
 Involuntary
 Relays information to and
 Relays information to
from skin and mucles
internal organs
Spooky links
 http://youtu.be/8-dZnp66t1Y
 www.youtube.com/watch?v=dxQmOR_QLfQ
 www.youtube.com/watch?v=2YZJt_Bw3eo