Basic Components of the Nervous System ---- NEUROGLIAL CELLS--- Matching

Question 1

NEUROGLIAL CELLS are also called….

Answer 1

Glial Cells

Question 2

How many NEUROGLIAL CELLS are in the body compared to neurons?

Answer 2

More numerous (900 billion) than neurons (100 billion) in the body

Question 3

What are the Differences from Neurons? (3)

Answer 3

1) Do not produce or conduct action potentials 2) Support neurons in various ways (depending on type) 3) Capable of mitosis throughout their life, unlike neurons—major cause of brain cancer

Question 4

*most numerous, up to 90% of some brain areas

Answer 4

Astrocytes

Question 5

Help produce and circulate (using cilia) cerebrospinal fluid (CSF) through the subarachnoid space surrounding the brain. Found in hollow brain cavities called VENTRICLES.

Answer 5

Ependymal Cells

Question 6

Form scar tissue in any areas of brain where neurons have died

Answer 6

Astrocytes

Question 7

Two types of neuroglial cells form myelin sheaths

Answer 7

Oligodendrocytes Schwann Cells/Neurolemmocytes

Question 8

Form myelin sheaths around many neuron axons located in the CNS (brain and spinal cord).

Answer 8

Oligodendrocytes

Question 9

Form a myelin sheath around a single neuron axon in the PNS (outside of brain & spinal cord).

Answer 9

Schwann Cells/Neurolemmocytes

Question 10

Blood-Brain Barrier—Sealing off of brain capillaries by astrocytes Prevents fluctuations (drastic changes) in ion levels (Na+, K+) inside brain which would interfere/disrupt the production of action potentials. Also prevents many toxic substances from crossing from the blood into the brain.

Answer 10

Astrocytes

Question 11

Structure—-Have a star-shaped body and many “feet” that cover the blood vessels and neurons in the brain

Answer 11

Astrocytes

Question 12

A _ _ _ _ is formed when one of two types of glial cells wraps around the axon of a neuron, forming concentric layers around it. Myelin, a _ _, is made inside this sheath.

Answer 12

myelin sheath

fat

Question 13

Octopus-like, with as many as 15 “arms”

Answer 13

Oligodendrocytes:

Question 14

_ _ _ _ allow severed (cut) neurons to grow back together (regenerate), making them the reason PNS neurons are capable of repair

(CNS neurons can’t regenerate/regrow)

Answer 14

Schwann cells

Question 15

_ _ _ _ (Myelinated):

*Top speed of action potential (AP) is 300 mph

Answer 15

White Matter

Question 16

_ _ _ _ (Unmyelinated):

*Ave. speed of AP is 2 mph

Answer 16

Gray Matter

Question 17

_ _ Nerves (with a myelin sheath) are called white matter and are found in the cortex of spinal cord and the medulla of brain.

Answer 17

Myelinated

Question 18

_ _ Nerves (without a myelin sheath) are called gray matter and are found in the medulla of spinal cord, the cortex of the brain, and as scattered nuclei within the brain.

Answer 18

Nonmyelinated

Question 19

Demyelination occurs with hard plaques replacing the myelin sheaths; Impaired AP conduction leads to loss of coordination, muscle weakness, tremors, numbness, visual & speech impairments.

What diseases occcur when this happens?

Answer 19

Multiple Sclerosis & Lou Gehrig Disease

Question 20

In white matter, the axon is NOT completely covered by the myelin sheath. Instead, there are small gaps

or _ _ _ _ _ _ where the axon is exposed.

Answer 20

Nodes of Ranvier

Question 21

The myelin sheath actually insulates the axon against electricity. This means an action potential (AP) cannot move _ _ the myelin sheath and is forced to hop from node to node. This greatly _ _ the speed of the AP as it moves down the axon.

Answer 21

through

increases