The Nervous The Nervous SystemSystemJORDIE SMELLS LIKE FEET IN THE JORDIE SMELLS LIKE FEET IN THE SUMMER ON A HOT DAY BECAUSE HE SUMMER ON A HOT DAY BECAUSE HE LIKES TO EAT “HOTDOGS” ALL THE LIKES TO EAT “HOTDOGS” ALL THE TIME.TIME.

Organization of the bodyOrganization of the body

The levels of organizations in a The levels of organizations in a multicellular organism goes as follows:multicellular organism goes as follows:

Cells, tissues, organs and organ Cells, tissues, organs and organ systems.systems.

There are 11 organ systems that help There are 11 organ systems that help maintain homeostasis.maintain homeostasis.

HomeostasisHomeostasis

It means to keep things in balance.It means to keep things in balance. Homeostasis keeps internal conditions Homeostasis keeps internal conditions

relatively constant despite change to relatively constant despite change to external environments.external environments.

Feedback InhibitionFeedback Inhibition

The process in which the stimulus The process in which the stimulus produces a response that opposes the produces a response that opposes the original stimulus.original stimulus.

Systems controlled by feedback inhibition Systems controlled by feedback inhibition are generally fully automated and very are generally fully automated and very stable.stable.

Ex: Like a thermostat. Ex: Like a thermostat.

The Actual Nervous The Actual Nervous SystemSystem

The nervous system controls and The nervous system controls and coordinates function throughout the body coordinates function throughout the body and responds to internal and external and responds to internal and external stimuli. stimuli.

The messages carried by the nervous The messages carried by the nervous system are electrical signals called system are electrical signals called impulses.impulses.

These cells are called neurons. These cells are called neurons.

CONTINUEDCONTINUED

The largest part of a typical neuron is the cell The largest part of a typical neuron is the cell body, it contains the nucleus and much of the body, it contains the nucleus and much of the cytoplasm. cytoplasm.

The dendrites which are attached to the cell The dendrites which are attached to the cell body, carry impulses from the environment or body, carry impulses from the environment or other neurons to the cell body. other neurons to the cell body.

It is then carried away from the cell body It is then carried away from the cell body through a long fiber called the AXON. through a long fiber called the AXON.

CONTINUED AGAINCONTINUED AGAIN

The axon is surrounded by the myelin The axon is surrounded by the myelin sheath. sheath.

The myelin sheath basically increases The myelin sheath basically increases the speed at which a impulse can travel.the speed at which a impulse can travel.

The SynapseThe Synapse

The synapse is the location at which a The synapse is the location at which a neuron can transfer an impulse to neuron can transfer an impulse to another cell.another cell.

NEUROTRANSMITTERS are chemicals NEUROTRANSMITTERS are chemicals used by a neuron to transmit an impulse used by a neuron to transmit an impulse across a synapse to another cell. across a synapse to another cell.

Central Nervous SystemCentral Nervous System

It relays messages, processes information & It relays messages, processes information & analyzes information. analyzes information.

It consists of the brain and spinal cord. It consists of the brain and spinal cord. Cerebrospinal fluid bathes the brain and spinal Cerebrospinal fluid bathes the brain and spinal

cord and acts as a shock absorber to protect cord and acts as a shock absorber to protect the central nervous system!the central nervous system!

It allows for exchange of nutrients and waste It allows for exchange of nutrients and waste products between blood and nervous tissue. products between blood and nervous tissue.

The BrainThe Brain

Pinky and the Brain are awesome. Pinky and the Brain are awesome. The cerebrum is the largest part of the The cerebrum is the largest part of the

brain, its responsible for intelligence, brain, its responsible for intelligence, learning, and judgment. learning, and judgment.

Still part of the BrainStill part of the Brain

The cerebellum is the second largest part The cerebellum is the second largest part of the brain. of the brain.

It coordinates and balances the actions It coordinates and balances the actions of the muscles so the body can move of the muscles so the body can move efficiently. efficiently.

More Brain PartsMore Brain Parts

The Brain Stem connects the brain and The Brain Stem connects the brain and spinal cord. spinal cord.

It regulates the flow of information It regulates the flow of information between the brain and the rest of your between the brain and the rest of your body. body.

Blood pressure, heart rate, breathing & Blood pressure, heart rate, breathing & swallowing are controlled by the BRAIN swallowing are controlled by the BRAIN STEM! STEM!

The other part of the The other part of the central nervous systemcentral nervous system

The spinal cord is the main The spinal cord is the main communication link between the brain communication link between the brain and the rest of the body. and the rest of the body.

A reflex is a quick automatic response to A reflex is a quick automatic response to a stimulus such as SNEEZING and a stimulus such as SNEEZING and BLINKING. BLINKING.

I know you all blink.I know you all blink.

The Peripheral Nervous The Peripheral Nervous SystemSystem

It is divided up into the sensory division It is divided up into the sensory division and motor division.and motor division.

Sensory division takes care of the Sensory division takes care of the senses, such as smell, seeing, hearing, senses, such as smell, seeing, hearing, feeling and taste.feeling and taste.

Motor division takes care of movements, Motor division takes care of movements, such as thrusting and walking.such as thrusting and walking.

The Somatic and The Somatic and Autonomic SystemAutonomic System

The somatic system The somatic system is anything you have is anything you have conscious control conscious control over.over.

Such as, moving you Such as, moving you finger around, and finger around, and wiggling your tongue wiggling your tongue unbelievably fast.unbelievably fast.

The autonomic The autonomic system is anything system is anything you DON’T have you DON’T have conscious control conscious control over.over.

Such as breathing Such as breathing heavily and blinking.heavily and blinking.

The EyeThe Eye

It sees stuff.It sees stuff. Light enters the eye through the cornea, Light enters the eye through the cornea,

the cornea helps focus the light which the cornea helps focus the light which then passes through the chamber filled then passes through the chamber filled with fluid called the aqueous humor.with fluid called the aqueous humor.

At the back of this chamber is the iris, the At the back of this chamber is the iris, the color part of the eye with an opening color part of the eye with an opening called the pupil. called the pupil.

More Eye StuffMore Eye Stuff

There are two types of photo receptors.There are two types of photo receptors. Rods.Rods. Cones.Cones. Rods are extremely sensitive to light but Rods are extremely sensitive to light but

they do not distinguish different colors.they do not distinguish different colors. Cones are less sensitive then rods but Cones are less sensitive then rods but

they do respond to light of different colors they do respond to light of different colors producing color vision.producing color vision.

DrugsDrugs

Stimulates increase heart rate, blood Stimulates increase heart rate, blood pressure, in addition stimulates increase pressure, in addition stimulates increase the release of neurotransmitters at some the release of neurotransmitters at some synapse in the brain. synapse in the brain.

Depressants slow down heart rate, Depressants slow down heart rate, breathing rate, lower blood pressure, breathing rate, lower blood pressure, relax muscles and relieve tension.relax muscles and relieve tension.

More DrugsMore Drugs

COCAINE causes sudden release in the COCAINE causes sudden release in the brain of neurotransmitters called brain of neurotransmitters called dopamine.dopamine.

Opiates mimic natural chemicals in the Opiates mimic natural chemicals in the brain known as endorphins, which brain known as endorphins, which normally help to overcome sensations of normally help to overcome sensations of pain. pain.

THE ENDTHE END

By: Sassie and Sierra and then By: Sassie and Sierra and then Jordie.Jordie.