D.(Ch. 14) CNS - Brain & Spinal Cord Coverings

Questions and Answers

What are the two protective coverings of the brain & spinal cord?

Outer covering is bone. Inner covering is meninges.

What are the three membranous layers of the meninges?

Dura mater, Arachnoid mater, Pia mater.

What is the Dura mater?

A membranous layer of meninges that is strong and fibrous.

What is the Falx cerebri?

Extension of the Dura mater that projects downward into the longitudinal fissure between two cerebral hemispheres. Signup and view all the answers

What are dural sinuses?

Veins that collect blood from brain tissues for return to the heart. Signup and view all the answers

What is the Superior sagittal sinus?

One of several dural sinuses. Signup and view all the answers

What is the Falx cerebelli?

Extension of the Dura mater that separates the two hemispheres of the cerebellum. Signup and view all the answers

What is the Tentorium cerebelli?

Extension of the Dura mater that separates the cerebellum from the cerebrum. Signup and view all the answers

What is Arachnoid mater?

A delicate, spiderweb-like layer between the dura mater and pia mater. Signup and view all the answers

What is Pia mater?

The innermost, transparent layer that adheres to the outer surface of the brain and spinal cord. Signup and view all the answers

What are several spaces that exist between & around the meninges?

Epidural space, Subdural space, Subarachnoid space. Signup and view all the answers

What is the Epidural space?

Space located between the dura mater and inside bony covering of spinal cord. Signup and view all the answers

What is the Subdural space?

Space located between dura mater and arachnoid mater. Signup and view all the answers

What is the Subarachnoid space?

Space located between arachnoid and pia mater that contains significant amounts of cerebrospinal fluid. Signup and view all the answers

What are the functions of the cerebrospinal fluid (CSF)?

Provides a supportive, protective cushion and acts as a reservoir of circulating fluid. Signup and view all the answers

What are the fluid spaces of the CSF?

Cerebrospinal fluid, Ventricles (1st, 2nd, 3rd, and 4th). Signup and view all the answers

Where is cerebrospinal fluid found?

Within the subarachnoid space around brain & spinal cord and in cavities & canals of the brain. Signup and view all the answers

What are the ventricles within the brain?

Fluid-filled spaces including the first & second (lateral), third, and fourth ventricles. Signup and view all the answers

What is the first & second ventricles within the brain?

Fluid-filled spaces (lateral) located in each hemisphere of the cerebrum. Signup and view all the answers

What is the third ventricle within the brain?

A thin, vertical pocket of fluid located below and medial to the lateral ventricles. Signup and view all the answers

What is the fourth ventricle within the brain?

A tiny, diamond-shaped space where the cerebellum attaches to the back of the brainstem. Signup and view all the answers

How does the foundation and circulation of CSF occur?

By separation of fluid from blood in the choroid plexus. Signup and view all the answers

What is the structure of the spinal cord?

Lies within spinal cavity and extends from foramen magnum to the lower border of the first lumbar vertebra. Signup and view all the answers

Study Notes

Protective Coverings of the CNS

Two main protective covering systems for the brain and spinal cord: outer covering is bone (cranial bones for the brain, vertebrae for the spinal cord) and inner covering is meninges.
Meninges extend beyond the end of the spinal cord into the spinal cavity.

Meninges Layers

Meninges consist of three membranous layers: dura mater, arachnoid mater, and pia mater.

Dura Mater

Strong, white fibrous tissue, serving as the outer layer of the meninges and the inner periosteum of cranial bones.
Has three significant extensions: falx cerebri, falx cerebelli, and tentorium cerebelli.

Falx Cerebri

An extension of the dura mater that projects into the longitudinal fissure between the two cerebral hemispheres.
Contains dural sinuses and superior sagittal sinus, functioning similarly to veins by collecting blood from brain tissues.

Dural Sinuses

Located within falx cerebri, they collect blood from the brain for return to the heart.

Superior Sagittal Sinus

A major dural sinus that runs along the superior aspect of the falx cerebri.

Falx Cerebelli

An extension of the dura mater, separating the two hemispheres of the cerebellum.

Tentorium Cerebelli

An extension of the dura mater that separates the cerebellum from the cerebrum.

Arachnoid Mater

A delicate, spiderweb-like membranous layer found between the dura mater and pia mater.

Pia Mater

The innermost layer of the meninges, transparent and adherent to the surface of the brain and spinal cord.
Contains blood vessels and forms a slender filament called 'filum terminale', which blends with the dura mater at the coccyx.

Spaces Between & Around Meninges

Three important spaces: epidural space, subdural space, subarachnoid space.

Epidural Space

Located between the dura mater and the bony encasement of the spinal cord, contains supportive fat and connective tissue.

Subdural Space

Situated between the dura mater and arachnoid mater, contains lubricating serous fluid.

Subarachnoid Space

Found between the arachnoid mater and pia mater, contains a significant amount of cerebrospinal fluid (CSF).

Functions of Cerebrospinal Fluid (CSF)

Provides cushioning and support to the brain and spinal cord.
Acts as a circulating reservoir, monitored by the brain for changes in the internal environment.

Fluid Spaces of CSF

Comprises cerebrospinal fluid and four brain ventricles: 1st and 2nd (lateral), 3rd, and 4th ventricles.

Ventricles in the Brain

Four fluid-filled spaces within the brain: first and second ventricles located in each hemisphere, the third ventricle below and medial to the lateral ventricles, and the fourth ventricle situated at the brainstem.

CSF Circulation

CSF is formed from blood in the choroid plexus and follows a specific circulation path from lateral ventricles to the central canal of the spinal cord and subarachnoid space before absorption into venous blood via arachnoid villi.

Structure of the Spinal Cord

Extends from the foramen magnum to the lower border of the first lumbar vertebra; features an oval-shaped cylinder that tapers downwards with two bulges (cervical and lumbar).

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Description

This quiz focuses on Chapter 14 of the central nervous system, covering the protective coverings of the brain and spinal cord. You'll learn about the outer and inner coverings, including cranial bones and meninges, as well as the three membranous layers of the meninges. Test your knowledge on these crucial topics!