Week 2 Continuing the Education of Nuerotransmitters :)

Week 2 consisted of learning more about nuerotransmitters and their functions, and also where it all began later on in the week.

The only excitable cells are: Muscle (skeletal, smooth, and cardiac). The change in activity is based on charge!

Bonds are being broken in the ASE of the ATP. ATP is Adenosine Tryphosphate which is a nucleotide acid. ATP uses the break off of carbon atoms to move ions from low to high concentration. The ratio for ATP is 3/2 Sodium ions to Pottassium Ions.

Ach is the only sodium ion channel that will open with a Nuerotransmitter. A receptor is the channel. VRC is postively charged and takes place at the axon hillock. CRC channels are located at the dendrites. Slow gates or channels are always open, and the fast gates or channels opens when Ach attachs. Nuerotransmitter #1 is the Pre Syn, and Nuerotransmitter #2 is the Post Syn.

Astrocytes are the accessorie cell that determines how much calcium is extra to push through sodium ions from N.T. #1 to N.T. #2. Astrocytes are star shaped and are the former of the blood brain barrier. They filter cells. If nuerons die they cannot undergo mitosis, and will become scar tissue.

Capillaries have the smallest diameter which means higher resistance and better for diffusion of cells. Capillaries are made up up tubes from simple squamous cells.

Oligodendrocytes form myelin sheaths in the CNS (brain and spinal). One oligodendrocyte can wrap multiple axons (hundreds). They can go undergo mitosis but is very difficult after wrapping many axons they cannot go in one direction, and is very unlikely to occur.

Schwann cells form myelin sheaths in the PNS. They can undergo mitosis and can retarget after being severed or highly damaged which is called Wallerian Regeneration. They can only wrap around one axon which enables them to fix itself after being severed or highly damaged.

Microglia is the smallest of the CNS. Phagocytic, defense cells in the CNS. Microglia is "the little pac man" They ingulf foreign material and release enzymes.

Ependymal Cells produce, help circulate cerebrospinal fluid in the CNS. CSF is an extract of blood. Porous Capillaries = Fenestrated Capillaries + ependymal cells = choroid plexous. Ependymal cells sit on the fenestrated capillaries that are "leaky" to make CSF.