Grey, White Matter- Brain Ventricles

Grey, White Matter- Brain Ventricles

Learning Objectives:

1. SW learn the differences between grey vs white matter

2. SW learn the ventricles of the brain

3. SW look at the cross section of the spinal chord!

Multiple Choice

If you are having trouble with your BALANCE and COORDINATION, which part of your brain should be checked?

• cerebrum

• cerebellum

• brain stem

• spinal cord

Multiple Choice

This part of the brain is the center of conscious thought. It controls our voluntary muscle movements like running and talking as well as our senses (hearing and tasting).

• cerebrum

• brain stem

• cerebellum

Multiple Choice

What is the function of the nervous system?

• to control and coordinate body functions and systems.

• to protect the body from harm.

• to identify pain and begin healing.

• to break down food.

Multiple Choice

Which part of the brain coordinates the actions of muscles and helps you maintain balance?

• brain stem

• cerebrum

• cerebellum

Multiple Choice

The nervous system_________

• receives information about what is going on in your body as well as what is going on around you.

• tells your body how to react to the information it receives.

• helps your body maintain homeostasis.

• all of the above.

Multiple Choice

The nervous system_________

• receives information about what is going on in your body as well as what is going on around you.

• tells your body how to react to the information it receives.

• helps your body maintain homeostasis.

• all of the above.

Nerve Cell

Nerve cells carry messages one way. Most nerve cells have a special cell that wraps around them that insulates them and helps the neuron to carry the message up to 250 mph! (300 meters/second)

The cell responsible for insulating the CNS neurons is known as the oligodendrocyte. 

Cells that have the oligodendrocytes wrapped around them are called white neurons and they make up the white matter of the CNS

Grey vs White Matter

The cortex of the brain is the outer layer of the brain. It is composed of neurons that are not wrapped or insulated and cell bodies of neurons. 

Neurons that do not have the insulating wrap (also known as myelin sheath) are referred to as gray neurons. Grey neurons carry messages much slower. 

They carry messages from 1-4 mph….much slower that the white neurons! 

The cortex of the brain is where choice making occurs! It really is much like voting. Neurons ‘vote’ and from the voting a choice is made. 

Brain Ventricles!

There are four ventricles of the brain: two lateral that meet on the midline, here the third ventricle can be found, and the fourth just beneath the third.

Spinal Cord

The spinal cord is much like an interstate that connects the brain to the body. It receives sensory input from the body and delivers motor output to specific areas of the body. 

Nerve pathways are ONE WAY. There has to be pathways going to the brain (sensory) and separate pathways coming from the brain (motor).

Neuron Structure

1. Dendrites: receive the message or stimuli When the proper stimuli opens the channels, Na+ enters and can cause the neuron to ‘fire’ or carry the message.  Send message to the Cell body

2. Cell Body: the message travels through the cell body to the axon hillock (#3) The cell body is also known as the Perikaryon (Peri=around and karyo=nucleus. In the cell body, there are lots and lots of rough ER and ribosomes.

Neuron Structure

3.  Axon of Hillock : If the message is strong enough and Hillock: triggers the axon hillock

4. Axon: Axons carry messages away from the cell body/axon hillock.

5. Axon Branches: The branches carry the message down to the bouton (#6). 

6. Boutons: The boutons release a neurotransmitter (NT) that will stimulate the next neuron or muscle.

Neuron Structure

7. Synaptic Vesicles: These small vacuoles contain the NT. They have traveled from the cell body down the axon to the bouton. As the message or nerve impulse enters the bouton, some of the synaptic vesicles bind to the cell membrane and release their NT by exocytosis. 

8.  Synaptic cleft or Synapse: This is the space between the two neurons or the neuron and muscle.

Types of Neuron

1. Unipolar

2. Bipolar

3. Multipolar

Multiple Choice

The tiny gap between neurons where nerve impulses are sent from one neuron to another.  It is where communication occurs between an axon and dendrite

• synapse
• axon terminal
• impulse
• myelin

Multiple Choice

Which is the correct sequence in the transmission of a neural impulse?

• axon, dendrite, cell body, synapse
• dendrite, axon, cell body, synapse
• synapse, axon, dendrite, cell body
• dendrite, cell body, axon, synapse

Multiple Choice

The extension that transmit electrical impulses from the som to other parts is:

• Myelin Sheaths

• Soma

• Dendrites

• Axon

Multiple Choice

What is the name of the part of the neuron that is pointed out in the image?

• Myelin sheaths

• Cell Body (Soma)

• Axon

• Dendrites

Multiple Choice

What is the name of the part of the neuron that is pointed out in the image?

• Myelin sheaths

• Cell Body (Soma)

• Axon

• Dendrites