Neurons And Glia

Question 1

What is the function of dendritic spines in neurons?

Answer 1

Receive signals from other neurons

Dendritic spines increase the surface area for synaptic connections.

Question 2

What is the role of the axon hillock?

Answer 2

Generates action potentials

The axon hillock is the region where the axon begins and is critical for the initiation of nerve impulses.

Question 3

What are Nissl bodies composed of?

Answer 3

Clusters of rough endoplasmic reticulum and free ribosomes

Nissl bodies are involved in the synthesis of proteins for neurotransmitter production.

Question 4

What type of flow of information do neurons exhibit?

Answer 4

Unidirectional

Information flows in one direction, from dendrites to axon terminals.

Question 5

What happens to neurons once they become specialized?

Answer 5

They become postmitotic and do not divide

This means they lose the ability to undergo mitosis.

Question 6

What are the main components of axonal transport?

Answer 6

• Kinesins (anterograde transport)
• Dyneins (retrograde transport)

Kinesins move materials towards the dendrites, while dyneins transport materials back to the cell body.

Question 7

What is myelination and its effect on nerve conduction?

Answer 7

Speeds up nerve conduction through saltatory conduction along nodes of Ranvier

Myelination allows electrical impulses to jump between nodes, increasing conduction velocity.

Question 8

What is the function of the endoneurium?

Answer 8

Surrounds individual axons and Schwann cells

The endoneurium provides a delicate connective tissue layer that supports nerve fibers.

Question 9

What are the three types of neurons based on function?

Answer 9

• Sensory neurons (afferent)
• Motor neurons (efferent)
• Interneurons

Sensory neurons send signals towards the CNS, motor neurons send signals away, and interneurons connect neurons within the CNS.

Question 10

What are the structural classifications of neurons?

Answer 10

• Multipolar
• Bipolar
• Pseudo-unipolar
• Unipolar

Multipolar neurons are the most common in the CNS, while bipolar neurons are rare and found in sensory pathways.

Question 11

What types of synapses exist in neuronal connections?

Answer 11

• Axo-dendritic
• Axo-somatic
• Axo-axonic

These synapse types refer to the connection points between the axon of one neuron and the dendrites, cell body, or axon of another.

Question 12

True or False: Neurons have an all-or-nothing response.

Answer 12

True

This means that once the threshold is reached, an action potential is generated without variation in strength.

Question 13

What is the role of astrocytes in the CNS?

Answer 13

• Structural support
• Blood-brain barrier regulation
• Energy storage
• Buffering K+ ions

Astrocytes play a critical role in maintaining homeostasis and supporting neuronal function.

Question 14

What do oligodendrocytes do?

Answer 14

Myelinate multiple axons

Oligodendrocytes are responsible for producing the myelin sheath in the CNS, which insulates axons.

Question 15

What is the function of microglia?

Answer 15

Immune defense and debris removal

Microglia act as the primary immune cells in the CNS, becoming phagocytic when activated.

Question 16

What do ependymal cells do?

Answer 16

Circulate cerebrospinal fluid

Ependymal cells line the spinal canal and have cilia that help in the movement of CSF.

Question 17

What are the two types of glia in the PNS?

Answer 17

• Schwann cells
• Satellite cells

Schwann cells provide myelination, while satellite cells offer structural and metabolic support.