Cerebrospinal fluid is secreted by ?

RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Applied Physiology

Easy

Appeared in: RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Explanation

The choroid plexus is a highly vascular structure located within the brain's ventricles (lateral, third, and fourth).
It is composed of specialized ependymal cells surrounding a core of capillaries and loose connective tissue.
These cells actively secrete cerebrospinal fluid (CSF) from blood plasma through a process involving active transport and ultrafiltration.
The choroid plexus is the primary site of CSF production, responsible for generating the majority of the fluid that circulates around the brain and spinal cord.

Option A: The spinal cord does not secrete CSF. It is a long, thin, tubular structure that is part of the central nervous system and is bathed and protected by CSF.
Option C: The cerebrum is the largest part of the brain and is involved in higher cognitive functions. While it is surrounded by CSF, its tissue does not secrete the fluid.
Option D: The cerebellum is located at the posterior base of the brain and is primarily responsible for motor control, coordination, and balance. It does not produce CSF.

Visual 1: Diagram - A sagittal view of the human brain showing the ventricular system. The location of the choroid plexus within the lateral, third, and fourth ventricles should be clearly labeled to illustrate the site of CSF production.
Visual 2: Flowchart - A diagram illustrating the circulation of CSF, starting from its production in the choroid plexus, flowing through the ventricles, into the subarachnoid space, and finally its absorption into the dural venous sinuses.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy and Physiology of Cerebrospinal Fluid (CSF) Production as background academic context rather than a clinical decision trigger.
Understanding CSF production is crucial for diagnosing and managing conditions like hydrocephalus, where there is an abnormal accumulation of CSF, leading to increased intracranial pressure (ICP).
A rare cause of hydrocephalus is a choroid plexus papilloma, a tumor that overproduces CSF.
Analysis of CSF obtained via lumbar puncture is a key diagnostic tool for conditions like meningitis, subarachnoid hemorrhage, and multiple sclerosis.

How to Approach the Question

First, identify the core concept of the question, which is the origin or secretion site of cerebrospinal fluid (CSF).
Recall the basic anatomy of the central nervous system, specifically the structures within the brain.
Evaluate each option based on its known physiological function.
Eliminate options that are parts of the brain or spinal cord but are not primarily involved in fluid secretion (e.g., cerebrum for thought, cerebellum for balance, spinal cord for nerve transmission).
Identify the choroid plexus as the specialized vascular structure within the ventricles specifically designed for producing CSF.

Concept Tested & Keywords

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