Nervous System

Root Words

Neurons

Units of nervous system that transmits information in the form of electrochemical changes

Dendrites: Receive electrochemical signals

Dendrites: Receive electrochemical signals

Axons: Extensions that send information

Dendrites: Receive electrochemical signals

Axons: Extensions that send information

Synapse: The junction between two communicating neurons

Dendrites: Receive electrochemical signals

Axons: Extensions that send information

Synapse: The junction between two communicating neurons

Myelin Sheaths: Fatty coating around Axon that insulates and increases rate of transition

Central Nervous System (CNS)

Central Nervous System (CNS)

Consisting of Brain and Spinal cord

Peripheral Nervous System

(PNS)

Peripheral Nervous System

(PNS) Consists of peripheral nerves that sends message back to CNS

Peripheral Nervous System

(PNS) Consists of peripheral nerves that sends message back to CNS

2 parts:Somatic

Autonomic

Somatic Nervous System

Part of the PNS that is responsible for nearly all voluntary muscle movement

Somatic Nervous System

Part of the PNS that is responsible for nearly all voluntary muscle movement

Exception: Reflexes

Autonomic Nervous SystemPart of the PNS that regulates the functions of internal organs such as the heart, stomach and intestines.

Autonomic Nervous SystemPart of the PNS that regulates the functions of internal organs such as the heart, stomach and intestines.

2 parts: Sympathetic Nervous System

Parasympathetic Nervous System

Sympathetic Nervous SystemPart of the Autonomic system that is responsible for “Fight or Flight”

Works by increasing heart rate and blood pressure, and slows down unnecessary systems

Often animals will soil themselves when fighting or scared

Parasympathetic Nervous SystemPart of the Autonomic System that is responsible for “Rest and Digest”

Lowers blood pressure, heart rate and works to save energy

Multipolar Neurons

Contains many processes (dendrites) and only one axon. Found mostly in the brain and spinal cord

Bipolar NeuronsContains only two processes, one axon, one dendrite

Found in eyes, nose, ears

Unipolar NeuronsContains only one process.

Located just outside the brain or spinal cord.

Brain Teaser

A H I M N O T U V W

Which of the letters above does not belong with the rest?

N It is not a mirror-image of itself

Resting PotentialWhen a nerve cell is undisturbed, the membrane remains in a polarized state (Always negative inside)

Threshold Potential

Approximately -55 millivolts, a level, when reached, will result in an action potential, sending a neural signal.

Action PotentialSodium ions (NA +) and Potassium ions (K+) diffuse in and out of the neuron, creating a rapid sequence of depolarization and repolarization.

Anatomy of the BrainCerebrum : largest

part of human brain

- Responsible for:

- Thought

- Language

- Senses

- Memory

- Voluntary movement

Anatomy of the BrainCerebellum : at base of

brain

-Responsible for:

- Muscle coordination

- Balance

- Posture

Anatomy of the BrainBrain Stem :

connects brain to spinal cord

-Responsible for:

- Breathing

- Swallowing

- Heartbeat

- Blood pressure

Brain TeaserThere is a town where 5% of all the people living there

have unlisted phone numbers. If you selected 100 names at random from the town’s phone directory, on average, how many of these people would have unlisted phone numbers?

0 They would not be in the phone book if their number was unlisted

Problems of the Nervous System

Concussion

A temporary disturbance of the brain’s ability to function due to a hard blow to the head

Paralysis

A loss of sensation and movement of part of the body due to an injury of the spinal cord or brain

Parkinson’s Disease

The brain does not produce enough of the neurotransmitter that transmits messages from the brain to the muscles

Symptoms: tremors, rigid muscles, shuffling walk, and loss of facial expression

Red areas show where chemical is stored

Alzheimer’s Disease

A gradual shrinking of the neurons in the cerebrum

Symptoms: memory loss, emotional disturbances, inability to function on own, death

Epilepsy

Abnormal transmission of messages between the neurons in the brain

Symptoms: seizures