Introduction to the Nervous System: Online:

Remember you will only ever be tested on the material covered in our textbook. Anything mentioned in a video or photograph or link that is not included in our textbook will not be included on our exams.

Introduction:

https://www.youtube.com/watch?v=qPix_X-9t7E

Neuroglial Cells:

https://www.youtube.com/watch?v=64MgiEDWyRg

Astrocytes: hold neurons in place and thus making sure all the neurons make all the correct connections to the other neurons. So much more than just supporting the neurons but they make sure the brain is correctly connected just like you need all the proper connections on a circuit board to make that computer chip actually work.

Oligodendrocytes: They myelinate the axon of a neuron. Picture the oligodendrocyte wrapping itself multiple times around the skinny axon of a neuron. Look closely and follow the growing tip of the oligodendrocyte, see how it wraps over and over again around the thin axon of the neuron.

So, a very thin extension of the oligodendrocyte keeps encircling the axon. That very thin extension is the phospholipid bilayer becoming wrapped and wrapped. Phospholipid is ‘lipid’ which is another name for fat. That dark staining layer after layer is mostly ‘fat’. That is what myelin is, layers of fat. It even looks white like fat does. Hence the statement, ‘oligodendrocytes myelinate axons’.

Microglial Cells: Simply the immune cells that are permanently stationed in the brain. You have immune cells everywhere in the body attacking foreign bacteria and viruses. Some are always in the lungs. Some are always in the skin. Some are always in the brain and those are called microglial cells.

Ependymal Cells: The brain is not completely solid. It has 4 fluid filled open spaces called ventricles. So, this open space must be lined with epithelial cells. These epithelial cells are called ependymal cells. Some of these epithelial cells that are called ependymal cells are glandular epithelium meaning that they are secretory. The fluid they secrete enters the ventricles and is called the ‘cerebral spinal fluid’ or CSF.

Schwann Cells: One of the most important functions of the Schwann cell is to myelinate the axons of the peripheral nervous system. They work like the oligodendrocytes of the central nervous system. However peripheral nerves can regenerate whereas nerves in the central nervous system cannot. It is believed the Schwann cells have something to do with regeneration in the PNS. As you probably know, any damage to the neurons in the brain or spinal cord (CNS) is permanent. Damage to neurons in the PNS where the Schwann cells do the myelination can show some repair. A deep cut in your finger may damage peripheral nerves but the numbness in your finger will go away once these neurons in the PNS regenerate. You can damage (burn) PNS neurons on your tongue (taste buds) with too hot soup or a hot drink but they will regenerate, and your taste will come back.

Sympathetic vs. Parasympathetic Nervous System:

https://www.youtube.com/watch?v=S62DBpjS1EI

Cranial Nerves:

As you learn:

-the names of the twelve cranial nerves (and their Roman numeral);

-the opening in the skull they pass through;

-the locations of cranial nerves I, II, and III on the brain;

-their functions.

You must also group them according to things they have in common.

Cranial nerves I, II, and VIII go together……why?

Cranial nerves III, IV, and VI go together…….why?

Cranial nerves V and VII go together…….why?

https://www.youtube.com/watch?v=oZGFrwogx14