Meninges
The meninges are three membranes that surround the brain and spinal cord, helping to protect and stabilize them along with other important functions.
1) Start with this video:
2) Then, read this article: Know Your Brain - Meninges
3) Watch this video to learn about a well-known inflammatory disease of the meninges:
4) Finally, answer these questions to test your understanding:
1. This is the thinnest and innermost meningeal layer; it adheres closely to the surface of the brain:
- A. dura mater
- B. arachnoid mater
- C. pia mater
- D. denticulate mater
Show Answer
Correct answer: C
The pia mater is the thinnest and innermost layer of the meninges. It adheres to the surface of the brain, closely following all of the contours of the brain.
2. Where is the subarachnoid space located?
- A. between the dura mater and the arachnoid mater
- B. between the pia mater and the brain
- C. between the arachnoid mater and the pia mater
- D. between the dura mater and the skull
Show Answer
Correct answer: C
The subarachnoid space is found between the arachnoid mater and the pia mater. The subarachnoid space is filled with cerebrospinal fluid (CSF).
3. This is the outermost and thickest layer of the meninges:
- A. pia mater
- B. arachnoid mater
- C. dura mater
Show Answer
Correct answer: C
The meninges are a group of membranes that surround the brain and spinal cord, providing protection and support as well as serving a number of other purposes. The outermost and thickest layer of the meninges is the dura mater. It is a tough and fibrous layer that helps protect the brain.
4. Which thin, web-like extensions of the arachnoid mater span the subarachnoid space and connect the arachnoid mater to the pia mater?
- A. denticulate ligaments
- B. arachnoid trabeculae
- C. choroid plexi
- D. filum terminale
Show Answer
Correct answer: B
Arachnoid trabeculae are delicate connective tissue strands that extend from the arachnoid mater to the pia mater, giving the subarachnoid space its “spider web” appearance.
5. How is meningitis definitively diagnosed?
- A. lumbar puncture (aka spinal tap)
- B. neuroimaging (CT or MRI)
- C. physical exam
- D. urinalysis
Show Answer
Correct answer: A
A lumbar puncture involves taking a sample of cerebrospinal fluid from around the spinal cord; it is the only definitive way to diagnose meningitis. Neuroimaging, a physical exam, and blood tests can all support the diagnosis or provide additional information on the infection.
