The Nervous SystemBy: Alan Bui, Andrew Chen, and Terrance Ku

Neuron Structure

• Most organelles are found in the cell body• Axons are covered in

myelin sheaths• Axons branches end

in a synaptic terminal

FUN FACT!

If you were to line up all of the neurons in the body of one

person, that line's length would be about 965 kilometers long!

Glia

• Important for structural integrity of nervous system• More glia than

neurons• Many different

types

FUN FACT!

When a child is developing in the mother's womb, the child's neuron

population grows at a rate of 250,000 neurons per minute!

Depolarization and Repolarization

• Suggested in 1900• Electrons contribute very little to the charge of a membrane• Nerves conducting an impulse cannot be activated until the original

polarity of the membrane is restored

Graded and Action Potentials

Nerve Impulses

• Nerve cells respond to changes in pH• Small spaces between neurons and effectors are called synapses• Two kinds of synapses:• Electrical• Chemical

Direct and Indirect Synaptic Transmission

• Direct Synaptic Transmission:• Neurotransmitters cross synapse directly

• Indirect Synaptic Transmission:• Signal transduction pathway

Summation of Postsynaptic Potentials

Neurotransmitters

• Acetylcholine• Biogenic Amines• Amino Acids and Peptides• Gases

FUN FACT!

Only 4% of brain cells are used at once and the rest are kept in

reserve!

Parts of the Brain

FUN FACT!

When we fall in our dreams, it is an example of our minds trying to

recreate the sensations we attribute to our dreams to make

them more plausible.

Parts of the Brain

FUN FACT!

The right side of the brain controls the left side of the body, while the left side of the brain controls the

right side of the body!

Limbic System

Types of Nervous Systems

• Central Nervous System• Peripheral Nervous System• Somatic Nervous System• Autonomic Nervous System

Sympathetic System

• Responsible for fight or flight response in the body• Very fast communication• Sympathetic Receptors:• Alpha 1, Alpha 2, Beta 1, Beta 2

FUN FACT!

When people are scared and they excrete wastes in their pants, it is due to their sympathetic nervous system relaxing the bladder and

contracting the rectum!

Parasympathetic System

• Responsible for keeping the body in its rest state• Located in the vagus nerve• Stimulated by

parasympathomimetics and inhibited by parasympatholytics

Nervous System Diseases

• Schizophrenia• Depression• Parkinson’s Disease

ACTIVITY TIME!!!

• 3 scenarios will be given• Role play what would happen

between two neurons at the cellular level• Work together to complete the

required task at hand• HAVE FUN!

• Acetylcholine (1 person)• Receptor (1 person)• Ion Gates (2 people)• Cholinesterase (1 person)• Membrane (4 people)

SCENARIO 1

Simple Muscle Contraction

Scenario 2

Simple Muscle Relaxation

Scenario 3

INSECTICIDE SPRAY