Unit 4B- Supporting Cells

Unit 4B- Lesson 2: Supporting Cells

Multiple Choice

At what stages do Sodium/Potassium Channels open?

• Repolarization/ Repolarization
• Depolarization/ Hyperpolarization
• Hyperpolarization/ Repolarization
• Depolarization/ Repolarization

Multiple Choice

Why is -55 mV a significant number?

• This is the largest charge achieved during an action potential

• This is the threshold required to complete an action potential

• This is the resting charge of a neuron

• This is the charge when all the sodium is inside the cell

Multiple Choice

What number on the graph represents the Depolarization phase?

• 1

• 2

• 3

• 4

Multiple Choice

Which ions are involved in the electrical nerve impulse?

• Iodine and Sodium

• Potassium and Sodium

• Iron and Sodium

• Calcium and Iodine

Multiple Choice

When a neuron is resting, the inside of the axon has a ____________ charge.

• -55 mV

• -70 mV

• 40 mV

• -75 mV

Multiple Choice

When a neuron is depolarized, what are the first channels to open?

• Sodium

• Potassium

• Calcium

• ACTH

Multiple Choice

What number(s) on the graph represents the Resting Potential?

• 1 and 2

• 1 and 5

• 2 and 3

• 3 and 4

Multiple Choice

Part of a neuron that receives information from other neurons

• axon

• dendrites

• myelin sheath

• synapse

Learning Objectives

SW learn the cells that support the neurons in CNS and PNS; Microglia, astrocytes, ependymal cells, Schwann cells and oligodendrocytes

Characteristics of Supporting cells

1. All the supporting cells together are referred to as Neuroglia. 

2. Most of the supporting cells are in reversible G0, so they have the ability to become mitotic if needed

3. Each supporting cell has a specific job to carry out.

Grey vs White Neurons

1. Grey neurons carry their messages through the dendrite-cell body- axon hillock-axon branches-bouton. - They have no myelin sheath

2. White neurons move the signal faster compared to grey neurons due to the presence of a myelin sheath.

Oligodendrocytes

1. CNS (Central Nervous System - Brain and Spinal cord), the myelination is created by oligodendrocytes.

2.Each oligodendrocyte can reach out and insulate a portion of a neuron process of different neurons. 

3. Oligodendrocytes also help in creating the structural framework of the CNS.

Schwann cells

1. PNS (Peripheral Nervous System) Schwann cells create the myelination.

2. These cells myelinate the neuron processes differently with the same result.

3. Only one Schwann cell will myelinate a small section of the axon or dendrite

Astrocytes

This cell has many important functions

1) Feeding the neuron! 

2) Protecting the neuron! 

3) Structural support! 

4) Leader of other cells! 

5) Blood volume control!

Microglia: The ‘janitors’ of the CNS!

Microglia were ‘born’ in the red bone marrow during embryonic development and migrated to the CNS where they specialized into Microglia. Microglia primary job is to keep the CNS clean!

Ependymal cells: CSF is our job!

1. Ependymal cells have the job of making and circulating cerebrospinal fluid.

2. They line the brain ventricles and central canal of the spinal cord.

3. These cells have cilia on their apex during the embryo stage. Once in adulthood, only the ependymal cells in the brain ventricles have cilia.

Multiple Choice

Neuroglial cells that form the fatty myelin sheath on neurons in the CNS are ___________ in the PNS are ________________?

• ganglia and oligodendroglia

• astrocytes and schwann cells

• schwann cells and oligodendroglia

• oligodendroglia and schwann cells

Multiple Choice

The cells that form the lining of the cavities of the brain and spinal cord and line the fluid-filled ventricles of the brain are called?

• arachnoid cells

• schwann cells

• ependymal cells

• neuroglia cells

Multiple Choice

Myelinated neurons are _____________ unmyelinated neurons are ______________?

• white mater, gray mater

• pink mater, gray mater

• gray mater, white mater

• blue mater, pink mater

Multiple Choice

What is the main function of oligodendrocytes?

• Production of insulation and protection
• Maintain the health of the neuron
• Brace and support the neuron to it's nurtient supply
• Lining of the central cavities to circulate spinal fluid

Multiple Choice

Which neuron structure wraps tightly around the axon in layers composed of myelin?

• dendrites

• axon

• schwann cells

• cell body

Multiple Choice

Which neuron structure wraps tightly around the axon in layers composed of myelin?

• dendrites

• axon

• schwann cells

• cell body