Identify the meningeal (or associated) structures described below: (1 point)
- Outermost meninx that covers the brain and is composed of tough, fibrous connective tissue
- Location of CSF production
- Innermost menirx that covers the brain
- Structures instrumental in returning cerebrospinal fluid (CSF) to the venous blood in the dural venous sinuses
- A dural fold separating the cerebrum from the cerebellum
The correct answer and explanation is :
Answers:
- Dura mater
- Choroid plexus
- Pia mater
- Arachnoid granulations (or arachnoid villi)
- Tentorium cerebelli
Explanation:
The meninges are protective membranes that surround the brain and spinal cord, consisting of three layers: dura mater, arachnoid mater, and pia mater.
- Dura Mater: The outermost meninx is the dura mater, which is composed of tough, fibrous connective tissue. It provides structural support and protection for the brain. The dura mater has two layers: the periosteal layer (attached to the inner surface of the skull) and the meningeal layer (closer to the brain).
- Choroid Plexus: The choroid plexus is found within the ventricles of the brain and is responsible for producing cerebrospinal fluid (CSF). It consists of a network of capillaries covered by ependymal cells, which filter plasma from the blood to create CSF.
- Pia Mater: The pia mater is the innermost meninx, which tightly adheres to the surface of the brain and spinal cord. It follows the brain’s contours, providing a protective barrier and supporting blood vessels that nourish neural tissue.
- Arachnoid Granulations (Arachnoid Villi): These structures protrude into the dural venous sinuses (especially the superior sagittal sinus) and allow excess CSF to be absorbed into the bloodstream, maintaining proper intracranial pressure.
- Tentorium Cerebelli: The tentorium cerebelli is a fold of the dura mater that separates the cerebrum (occipital lobes) from the cerebellum. It helps support the brain and prevents excessive movement of the cerebrum, protecting the cerebellum from compression.