Classifying Neurons and Glia

What are the three classifications based on the number of neurites?

Unipolar (one neurite), Bipolar (two neurites), Multipolar (three or more neurites)

What type of cells are predominantly found in the cerebral cortex?

Stellate cells (star-shaped) and Pyramidal cells (pyramid-shaped)

What is a spiny neuron?

A neuron with a spine on its dendrites.

What differentiates Golgi type I neurons from Golgi type II neurons?

Golgi type I neurons have long axons that extend from one part of the brain to another; Golgi type II neurons have short axons that do not extend past the cell body vicinity.

What is the role of astrocytes in the nervous system?

Astrocytes fill spaces between neurons, influence neurite growth, regulate extracellular chemical content, and maintain the blood-brain barrier.

What is the myelin sheath and its function?

A covering formed by layers of myelin that insulate axons and speed up electrical impulse conduction.

What are ependymal cells responsible for?

Ependymal cells line fluid-filled ventricles in the brain and produce cerebrospinal fluid (CSF).

How do microglia contribute to the health of the nervous system?

Microglia are phagocytes that remove debris from dead or degenerating neurons and help remodel synaptic connections.

Which neurotransmitter is released by motor neurons that command voluntary movements?

Acetylcholine.

What distinguishes chlonergic neurons?

Cholinergic neurons express the genes necessary for the synthesis and use of acetylcholine as a neurotransmitter.

What is a key characteristic of oligodendrocytes?

Oligodendrocytes are found in the central nervous system and myelinate several axons.

What is the function of Schwann cells?

Schwann cells myelinate a single axon in the peripheral nervous system.

What are the primary immune defense cells in the CNS?

Microglia.

What is the main distinguishing feature of astrocytes?

Astrocytes are the most numerous glial cells and fill the spaces between neurons.

What happens in neurogenesis and neurodevelopment?

Radial glia can develop new neurons and assist in the movement of new neurons through the brain.

What role do glial cells play in maintaining the extracellular environment?

Glial cells regulate the concentration of substances like potassium ions that can interfere with neuron function.

What can be inferred from the term 'Aspinous' related to neurons?

Aspinous refers to neurons that do not have spines on their dendrites.

How can gene expression affect neuronal shape?

Differential gene expression can cause pyramidal and stellate cells to develop distinct shapes.

What is the function of the Node of Ranvier?

It is a short length where the axonal membrane is exposed and interrupts the myelin sheath periodically.

What is the anatomical significance of stellate cells?

Stellate cells can either be spiny or aspinous and are found in the cerebral cortex.

What is the relationship between excitatory signals and neurotransmitter receptors in astrocytes?

Astrocytes possess neurotransmitter receptors that trigger electrical and biochemical events inside the glial cell.

How are different types of neurons classified?

They can be classified based on structure (number of neurites), connections, axon length, gene expression, and neurotransmitter differences.

What do all pyramid cells have in common concerning dendritic classification?

All pyramid cells are considered spiny.

How do astrocytes affect synaptic junctions?

Astrocytes can envelop synaptic junctions, restricting the spread of neurotransmitters released.

What is the role of vasculature in the nervous system?

Vasculature (arteries, veins, and capillaries) delivers nutrients and oxygen to neurons by blood.

What is the impact of microglia on synaptic connections?

Microglia remodel synaptic connections by removing excess and damaged synapses.