Neuroanatomy Lecture 2: Meninges

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Questions and Answers

What is the shape of the falx cerebri?

Crescent-shaped (correct)

Circular-shaped

Sickle-shaped

Triangular-shaped

What runs along the attachment of the tentorium cerebelli to the falx cerebri?

Inferior sagittal sinus

Superior sagittal sinus

Straight sinus (correct)

Transverse sinus

What is the function of the tentorium cerebelli?

It forms the walls of the posterior cranial fossa and supports the parietal lobes

It supports the frontal lobes of the cerebral hemisphere

It forms the roof of the posterior cranial fossa and supports the occipital lobes (correct)

It forms the floor of the posterior cranial fossa and supports the temporal lobes

What is the attachment site of the falx cerebri?

Base of the skull Signup and view all the answers

What is the shape of the falx cerebelli?

Sickle-shaped Signup and view all the answers

What runs along the attachment of the tentorium cerebelli to the petrous bone?

Superior petrosal sinus Signup and view all the answers

What is the function of the tentorial notch?

It allows for the passage of the midbrain Signup and view all the answers

What is the attachment site of the falx cerebelli?

Internal occipital crest Signup and view all the answers

What is the primary function of the meninges?

Mechanical protection of brain and spinal cord Signup and view all the answers

Which layer of dura mater lines the inner surface of bones?

Endosteal layer Signup and view all the answers

What is the function of the dural venous sinuses?

Venous drainage of cranium Signup and view all the answers

How many septa are sent inward by the meningeal layer?

4 Signup and view all the answers

What is the name of the septum that lies in the midline between the two cerebral hemispheres?

Falx cerebri Signup and view all the answers

What is the function of the septa sent inward by the meningeal layer?

To restrict rotatory displacement of the brain Signup and view all the answers

What is the name of the sinus located in the Falx cerebri?

Inferior sagittal sinus Signup and view all the answers

Where does the endosteal layer of the dura mater of the cranium meet the endosteal layer of the dura mater of the spinal cord?

They do not meet Signup and view all the answers

What is the function of arachnoid granulations?

To allow CSF to re-enter the blood circulation Signup and view all the answers

What is the location of subdural hemorrhage?

Between arachnoid mater and pia mater Signup and view all the answers

What is the characteristic of subarachnoid hemorrhage?

Withdrawing heavily blood-stained cerebrospinal fluid Signup and view all the answers

What is the function of the subarachnoid space?

To separate arachnoid mater from pia mater Signup and view all the answers

What is the location of the superior cistern?

Around the superior sagittal sinus Signup and view all the answers

What is the characteristic of epidural hemorrhage?

Bleeding between inner surface of skull and outer layer of dura mater Signup and view all the answers

What is the function of the arachnoid mater?

To cover the brain and lie between dura mater and pia mater Signup and view all the answers

What is the name of the cistern that lies around the brainstem?

Interpeduncular cistern Signup and view all the answers

Where is the posterior fixed margin of the diaphragma sellae located?

Occipital sinus Signup and view all the answers

What is the function of the small opening in the center of the diaphragma sellae?

Allows passage of the pituitary gland stalk Signup and view all the answers

Which nerve branch is responsible for the innervation of the dura in the anterior cranial fossa?

Anterior and posterior ethmoidal nerves branch of ophthalmic division of trigeminal nerve Signup and view all the answers

What is the consequence of stimulation of sensory endings of the trigeminal nerve above the level of the tentorium cerebelli?

Referred pain in the form of headache Signup and view all the answers

Which artery provides the most significant blood supply to the dura?

Middle meningeal artery Signup and view all the answers

Which vein drains the blood from the middle meningeal artery?

Maxillary vein Signup and view all the answers

What is the consequence of stimulation of sensory endings of the trigeminal nerve below the level of the tentorium cerebelli?

Referred pain to the back of the neck and scalp Signup and view all the answers

What is the location of the dura that is innervated by the first three cervical nerves and the vagus nerve?

Below the tentorium cerebelli Signup and view all the answers

Study Notes

Meninges

Definition: Three protective membranes surrounding the brain and spinal cord in the skull and vertebral column
Functions: Mechanical protection of brain and spinal cord, protection of cerebral and spinal blood vessels, and pathway for cerebrospinal fluid (CSF)

Dura Mater

Consists of two layers: endosteal layer and meningeal layer
Endosteal layer lines the inner surface of bones, while meningeal layer is a dense, strong, fibrous membrane covering the brain
Dural venous sinuses are located between the two layers, responsible for venous drainage of the cranium
Meningeal layer sends inward four septa, dividing the cranial cavity and lodging subdivisions of the brain, restricting rotatory displacement

Septa of Dura Mater

Four septa: Falx Cerebri, Falx Cerebelli, Tentorium Cerebelli, and Diaphragma Sellae
Functions: restrict rotatory displacement of brain, divide cranial cavity, and lodge subdivisions of brain

Falx Cerebri

Shape: sickle-shaped fold of dura mater
Location: lies in the midline between two cerebral hemispheres
Two ends: anterior end attached to internal frontal crest and crista galli, posterior end blends with tentorium cerebelli
Base: upper fixed margin attached to skull, where superior sagittal sinus runs
Inferior sagittal sinus runs in its lower free margin, and straight sinus runs along its attachment to tentorium cerebelli

Tentorium Cerebelli

Shape: crescent-shaped fold of dura mater
Location: forms the roof of the posterior cranial fossa, covering the cerebellum and supporting the occipital lobes of the cerebral hemispheres
Attached to falx cerebri and falx cerebelli, with an inner free border and an outer fixed border
Tentorial notch: gap in front, allowing passage of the midbrain
Sinuses attach to tentorium cerebelli: straight sinus, superior petrosal sinus, and transverse sinus

Falx Cerebelli

Shape: small, sickle-shaped fold of dura mater
Location: attached to internal occipital crest, projects forward between two cerebellar hemispheres
Posterior fixed margin contains the occipital sinus

Diaphragma Sellae

Shape: small, circular fold of dura mater
Location: forms the roof of the sella turcica
Small opening in its center allows passage of the stalk of the pituitary gland

Dural Nerve Supply

Innervation:
- Anterior cranial fossa: anterior and posterior ethmoidal nerves (ophthalmic division of trigeminal nerve)
- Middle cranial fossa: recurrent meningeal branch, meningeal branch of maxillary division, and meningeal branch of mandibular division (all trigeminal nerve)
- Posterior cranial fossa: above tentorium cerebelli, recurrent meningeal branch (ophthalmic division of trigeminal nerve); below tentorium cerebelli, first three cervical nerves and vagus nerve
Trigeminal nerve stimulation produces referred pain: headache above level of tentorium cerebelli, neck stiffness below level of tentorium cerebelli

Dural Blood Supply

Small branches: internal carotid and maxillary arteries
Middle meningeal artery is of greater significance
Veins: middle meningeal vein follows branches of middle meningeal artery and drains into maxillary vein

Arachnoid Mater

Delicate, impermeable membrane covering the brain and lying between dura mater and pia mater
Subdural space: potential space between arachnoid and dura mater
Subarachnoid space: potential space between arachnoid and pia mater, filled with CSF
Arachnoid granulations: small projections into superior sagittal venous sinus
Subarachnoid cisterns: areas where arachnoid and pia are widely separated, e.g., chiasmatic, interpeduncular, pontine, cerebellomedullary, and superior cisterns

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Description

This quiz covers the definition and functions of meninges, the three protective membranes surrounding the brain and spinal cord.