spinal cord cards

The skull, meninges, cerebrospinal fluid, blood brain barrier.

What protects the brain from injuries?

What are the functions of the meninges in the brain?

cover and protect the CNS

enclose and protect the vessels that supply the CNS

contain the crebrospinal fuid.

—between pia and arachnoid matters.

What are the three types of Meninges?

The dura mater, the arachniod mater, the pia mater.

These three connective tissue membranes incase the brain and spinal cord.

The dura mater

The outermost, thickest, and most derable layer, made of dense fibrous connective tissue. it consists of two layers: perioteal and meningeal (the two layer are fused except to enclose the dural sinuses)

Arachnoid mater

Beneath the dura mater, named for its web-like network of collagen and elastic fibers.

Arachnoid villi

—finger-like projections of the arachoid mater that extend through the dura mater, its primary job is to act as one-way valves that reabsorb cerebrospinal fluid from the subarachnoid space back into the the bloodstream.

Pia Mater

The innermost, highly vascularized layer composed of delicate connective tissue. It adheres directly to the contours of the brain and spinal cord, dipping into every sulcus and fissure.

Cerebrospinal fluid

A clear, colorless bodily fluid produced in the brain ventricles that bathes, cushions, and nourishes the central nervous system. Mainly produce in the vascular structures called choroid plexus. arises from blood, 500 ml produced per day, 100-160 ml present at any one time.

Blood-brain barrier

Prevents most blood borne toxins from entering the brain (impermeable capillaries)

Not an absolute barrier

-nutrients such as oxygen pass through

-allows passage of alcohol, nicotine, and anesthetics.

Funtions and Location of the spinal cord

functions—Spinal nerves attach to it, provides twe-way conduction pathwa, major center for flexes.

locatio—runs through the vertebral canal, extends from the foramen magnum to the level of the vertebra L1 or L2.

conus medullaris

The tapered, cone-shaped located at the inferior end of the spinal cord, typically terminating at the L1-L2 vertebral levels in adults.

Filum Terminale

Extending from the tip of the conus medullaris to the coccyx, anchoring the spinal cord vertically. The lowest part of the spinal cord.

cauda equina

a collection of spinal nerve roots that extend downward from the conus medullaris within the subarachnoid space, resmbling a hosrse’s tail

Cervical and Lumbar enlargments

Where nerves for upper and lower limbs arise. It houses motor neurons that innervate the upper and lower limbs via plexuses

Cauda equina

collection of spinal nerve roots.

Spinal cord segments

Indicatet the region of the spinal cord from which spinal nerves emerge.

Designated by the spinal nerve that issues from it.

For example: T1 is the region where the first throractci nerve emerges two

What are the two deep grooves (surcos) that run the length of the cord?

Posterior (dorsal) median sulcus

Anterior (ventral) median fissure

White matter of the spinal cord.

outer region of the spinal cord.

composed of myelinated and nonmyelinated axons. the white matter makes possible the communication between spinal cord and brain.

Fibers in the white matter can classifed based on their fucntion

Ascending (sensory) fibers: carry incoming sensory information from perpheral receptors tot he brainstem, cerebellum, or thallamus.

Descending (motor) Fibers: Carry outgoing motor commands downward from the brain to motor neurons inthe anterior gray horn.

Cmmissural fibers: Fibers that ramain entirely within the spinal cord. They travel short distances up, down or across the midline..

Gray matter in the spianl cord.

Primarily neuronal cell bodies and some nonmyelinated axons.

—Regions of gray matter—

gray commissure

dorsal horns

ventral horns

lateral horns

What protects the spinal cord

Dura mater—a single layer surrounding spinal cord

arachnoid mater—lies deep to the dura mater

Pia mater—innermost layer

Denticulate ligaments—lateral extensions of pia mater.

What are the multineuron pathways that connect brain and body periphery

Ascending pathways—carry information to more rostral areas of the CNS

Descending pathways—carry information to more caudal regions of the CNS