Ch. 12.4- Glial Cells

Question 1

Can glial cells reproduce?

Answer 1

Yes, though cell division.

Question 2

What is the role of glial cells?

Answer 2

Protect neurons, support then, provide nourishment, and creates supportive scaffolding for all nervous tissue.

Question 3

What are the four types of glia cells?

Answer 3

Astrocytes, ependymal cells, microglia, oligodendrocytes

Question 4

What is the shape of an astrocyte? What do they do?

Answer 4

Star shaped

Nurture, protect, and guide neurons.

Question 5

What specifically do astrocytes do?

Answer 5

Help protect blood brain barrier
Regular interstitial fluid composition
Form structural support
Assist neuronal development
Occupy the space of dying neurons

Question 6

The ends of astrocyte processes are called?

Answer 6

Perivascular feet

Question 7

What is the role of perivascular feet in the astrocyte?

Answer 7

Cover and wrap around the capillaries of the brain.

Works with capillaries in the brain to form the blood brain barrier.

Question 8

How do astrocytes help regular interstitial fluid composition?

Answer 8

Help regulate interstitial fluid by absorbing K+ ions to make sure K+ ions are at right concentration for electrical activity.

Question 9

How do astrocytes support and organized neurons?

Answer 9

With their cytoskeletons.

Question 10

How do astrocytes help with neural development?

Answer 10

They secret chemicals in the fetal brain that help regulate the formation of connections between neurons.

Question 11

How do they occupy the space of dying neurons?

Answer 11

They replicate and fill that space.

Question 12

What are the cell type of ependymal cells?

Answer 12

Ciliated cuboidal or simple columnar cells.

Question 13

What is the function of ependymal cells?

Answer 13

Line the ventricles (internal cavities) of the brain and the central canal of the spinal cord.

Question 14

How do ependymal cells connect with other neurons?

Answer 14

With slender processes that branch extensively and make contact with other glial cells.

Question 15

Choroid plexus

Answer 15

Made of ependymal cells and nearby blood capillaries.

Question 16

What is the function of the choroid plexus?

Answer 16

Produce cerebral spinal fluid.

Question 17

What do the cilia of ependymal cells do?

Answer 17

Help circulate CSF.

Question 18

Microglial cells

Answer 18

Small glial cells- make up about 5% of CNS glial cells.

Phagocytic cells that protect against infections/toxins and clean up debris from dead nervous tissue.

Question 19

Oligodendrocytes

Answer 19

Large cells, bulbous body, and slender cytoplasmic extensions (processes) which wrap around and insulate neurons in the CNS through myelination.

Question 20

What are the two types of glial cells found in the peripheral nervous system?

Answer 20

Satellite cells

Neurolemmocytes

Question 21

Satellite cells

Answer 21

Flattened cells arranged around neuronal cell bodies in a ganglion.
They electrically insulate the cell body and regulate the exchange of nutrients and waste products between neuron cell bodies and their environment.

Question 22

What is another name for neurolemmocytes?

Answer 22

Schwann cells.

Question 23

What do Schwann cells do?

Answer 23

Flattened and elongated cells the wrap around and insulate neurons in the PNS through myelination.

Question 24

What is myelin made of?

Answer 24

Repeating concentric layer of the plasma membrane of Schwann cells and oligodendrocytes.

Question 25

What is the promotion of lipid to protein in myelination?

Answer 25

Lot of lipids and small amounts of proteins.

Question 26

How does myelination in the CNS work?

Answer 26

The neurolemmocyte (Schwann cell) wraps itself around the axon in a 1 mm section forming the myelination with the nucleus and the cytoplasm pushed to the outside.

Question 27

Neurilemma

Answer 27

The portion of a Schwann cell (neurolemmocyte) that is pushed to the periphery of the sheath that it has created. Made of nucleus and the cytoplasm.

Question 28

neurofribil nodes

Answer 28

Nodes of ranvier- these are the gaps that are present between neurilemma cells that for the axon sheath along an axon.

Question 29

How are oligodendrocytes different than neurons?

Answer 29

Oligodendrocytes can wrap multiple different 1 mm sections of different axons and the cytoplasm and nucleus stay in the “central hub”.

Question 30

Un-myelinated axons

Answer 30

In the PNS these rest in depression in the neurolemocytes. In the CNS, unmyelinated axons are not associated with oligodendrocytes.