Neuroglia and Edema Quiz

Questions and Answers

What is the primary characteristic of interstitial edema in obstructive hydrocephalus?

Increased pressure within the ventricular system

Fluid accumulation in the nerve cell bodies

Nerve cell malfunction due to ATP depletion

Rise in CSF pressure forcing fluid into the ECS (correct)

Which of the following is a cause of cellular swelling in oligodendroglia?

Deficiency in synaptic junction connections

Accumulation of myelin within the cells

Nerve impulse propagation failure

Toxic or metabolic factors affecting the ATP Na-pump (correct)

What percentage of intracranial tumors do neuroglial tumors account for?

50 to 60%

40 to 50% (correct)

20 to 30%

30 to 40%

Which type of cell is primarily responsible for myelination of peripheral nerves?

Schwann cells Signup and view all the answers

Which type of tumors arise from astrocytes?

Astrocytomas Signup and view all the answers

What are the scavenger cells of the central nervous system?

Microglial cells Signup and view all the answers

Which process is associated with Nissl substance in nerve cell bodies?

Protein synthesis Signup and view all the answers

What is a defining characteristic of gliomas?

They are the most common type of brain tumors. Signup and view all the answers

What is the term for the period during which another action potential cannot be elicited after a nerve impulse has spread?

Refractory Period Signup and view all the answers

Which of the following describes the speed of rapid cell transport?

100 to 400 mm per day Signup and view all the answers

In terms of organelle movement, which structure is NOT mentioned as being transported by cell transport mechanisms?

Mechanical vesicles Signup and view all the answers

How do the sizes and frequencies of cell transport impact the process?

Neither size nor frequency alter the process Signup and view all the answers

What is the rate of slow cell transport?

0.1 to 3 mm per day Signup and view all the answers

What is the primary role of centrioles in nerve cells?

They maintain and organize microtubules. Signup and view all the answers

Which of the following correctly describes the resting potential of a nerve cell?

There is a higher passive efflux of K+ ions compared to the influx of Na+ ions. Signup and view all the answers

What type of ion predominantly contributes to the steady potential difference of -80mV in nerve cells?

K+ ions Signup and view all the answers

What are lipofuscin granules primarily associated with in nerve cells?

Accumulation resulting from lysosomal activity. Signup and view all the answers

Where are melanin granules primarily found within neurons involved in dopamine synthesis?

In the cell body cytoplasm. Signup and view all the answers

How is a nerve cell stimulated for action potential generation?

Via electrical, mechanical, or chemical means. Signup and view all the answers

Which statement accurately describes the chemical composition of nerve cell membranes?

The membrane has greater permeability to K+ ions than to Na+ ions. Signup and view all the answers

What effect does lysosomal activity have in the context of aging nerve cells?

Leads to the accumulation of lipofuscin. Signup and view all the answers

What is the primary function of an axon?

To conduct impulses away from the cell body Signup and view all the answers

What distinguishes amacrine neurons from typical neurons?

They lack an axon and branch profusely Signup and view all the answers

What feature of axons allows for the rapid conduction of impulses?

Increased diameter Signup and view all the answers

Which part of the axon is considered the most excitable and the origin of the action potential?

Initial segment after the axon hillock Signup and view all the answers

What are varicosities in the context of axons?

Enlarged areas resembling beads near axon terminations Signup and view all the answers

What is the typical length range for axons?

0.1 mm to 3 meters Signup and view all the answers

How does axon diameter affect impulse conduction speed?

Larger diameter conducts impulses faster Signup and view all the answers

What happens to the amplitude of action potentials in different axon sizes?

They increase with larger axon diameter Signup and view all the answers

Which of the following accurately describes the nucleus?

Houses the nucleolus for ribosomal RNA synthesis Signup and view all the answers

What is the significance of the Barr Body in females?

Represents one of the compacted X chromosomes Signup and view all the answers

Which of the following best describes microfilaments?

Are involved in the formation of new cell processes Signup and view all the answers

What does the nuclear envelope primarily consist of?

Double-layered membrane with specialized pores Signup and view all the answers

Why are microtubules important in cellular function?

They serve as tracks for organelle movement Signup and view all the answers

Which of the following statements about neurofilaments is true?

They are a key component of the cytoskeleton Signup and view all the answers

What role do granular and agranular ER play in the cytoplasm?

They are rich in resources for protein and lipid synthesis Signup and view all the answers

What is the diameter of microfilaments?

About 3 to 5 nm Signup and view all the answers

Study Notes

Oligodendroglia and Edema

Oligodendroglia cells are integral in myelination and contribute to 40-50% of intracranial tumors.
Interstitial edema refers to fluid accumulation leading to cellular swelling; can occur in obstructive hydrocephalus due to rising cerebrospinal fluid (CSF) pressure.
Edema results when CSF is forced from the ventricular system into the extracellular space (ECS).

Neoplasms of Neuroglia

Tumors of neuroglia are called gliomas and can be highly invasive.
Types of gliomas include astrocytomas, which are the most encountered, and other kinds like ependymomas.

Nissl Substance and Cell Functions

Nissl substance is associated with protein synthesis and is important for nerve cell function.
Breakdown in plasma membrane ATP Na-pump leads to toxic and metabolic failures affecting neuronal activity.

Amacrine Neurons

Amacrine neurons are unique as they lack axons; instead, they typically branch extensively.
They play a role in processing visual information in the retina through local circuits.

Axonal Structure

Axons vary in size and perform differently based on their diameter:
- Larger axons conduct impulses rapidly.
- Smaller axons conduct impulses slowly.
The initial segment after leaving the axon hillock is the most excitable part, leading to action potential (AP) generation.

Cell Components

Nucleus:
- Central, large, and rounded with a prominent nucleolus for ribosomal RNA (rRNA) synthesis.
- Contains Barr Body, a compacted x-chromosome in females.
Cytoplasm contains rough and smooth endoplasmic reticulum and substances like lipofuscin, a byproduct that accumulates with age.

Cytoskeleton Components

Microfilaments (3-5 nm) formed by actin assist in cell shape and movements.
Microtubules (25 nm) serve as tracks for organelle movement and are key components of axon transport.

Membrane Potential

Potassium (K+) permeability is greater than sodium (Na+) permeability across the cell membrane, resulting in a resting potential of -80mV.
The inside of the cell membrane is negative relative to the outside, known as the resting potential.

Cell Transport Mechanisms

Function of cell transport includes the movement of organelles and materials crucial for neuron maintenance and function.
There are two types:
- Rapid Cell Transport (100-400 mm/day).
- Slow Cell Transport (0.1-3 mm/day).

Synapses

Synapses are the junctions where two neurons are in close proximity, allowing for signal transmission.

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Description

Test your knowledge on the roles of oligodendroglia in myelination, the impact of interstitial edema, and the types of neuroglial neoplasms. This quiz also covers essential cellular functions like protein synthesis and the distinctive features of amacrine neurons.