The Spinal Cord and Meninges

The most common cause of meningitis is viral. However, there are other causes including bacterial, parasitic and fungal infections. ________ meningitis is considered a medical emergency

Bacterial

The spinal cord ends at

L1 -L2

The adult spinal cord typically terminates at vertebral level _____. The adult level is attained by about ____ months post -term.

L1 -L2 2 -3

________ arteries are another source of blood supply to the spinal cord. These originate from the: i) ________ and ________ arteries in the neck region; ii) ________ arteries in the thorax; and iii) ______ arteries in the abdomen, _____________ arteries enter the vertebral canal via the _____ at each vertebral level (hence the term "segmental").

Segmental spinal vertebral cervical posterior intercostal lumbar Segmental spinal intervertebral foramen

Recall that the _______ space is located between the dural sac and the vertebral canal. This is an important space in which anesthetic may be injected to provide relief from pain or inflammation. An epidural injection _____ be performed at any vertebral level.

extradural (or epidural) can

Both the _______ and _____ mater continue distally to the S2 vertebra.

arachnoid dura

The middle meningeal layer is the ___________. The ___________ lines the dural sac. The space between the dural sac and the arachnoid mater is the _______. The web-like trabeculae of the arachnoid traverse the _______ space - the space between the arachnoid and the deepest meningeal layer, the pia mater. __________ is located in the subarachnoid space, which protects and nourishes the spinal cord.

arachnoid mater arachnoid mater subdural space subarachnoid Cerebrospinal fluid (CSF

Dorsal and ventral nerve rootlets from the lumbar, sacral and coccygeal nerves continue distally to form the ________ (horse's tail)

cauda equina

The dura mater extends into the intervertebral foramen as the ________, thus protecting the dorsal and ventral rootlets and dorsal root ganglia of the spinal nerves.

dural root sleeve

The conus medullaris is anchored to the end of the _______ by a thin thread of pia mater called the _______ (terminal filament). The filum terminale fuses with the ______ as it emerges from the dural sac to anchor the dural sac to the ______.

dural sac filum terminale dura coccyx

Where does the spinal cord begin?

foramen magnum

Blood from ______ and _______ veins drains into an extensive venous network that resides in the ________ space of the vertebral canal, called the internal vertebral plexus. Ultimately, blood from the internal vertebral plexus drains into major systemic veins of the body.

longitudinal segmental epidural

Blood supply to the spinal cord derives from two main sources:

longitudinal arteries segmental spinal arteries

The spinal cord begins as a continuation of the _______ (lower portion of the brainstem) at the ________ (the opening in the base of the skull for passage of the spinal cord).

medulla oblongata foramen magnum

One reason to perform a spinal tap is to test for _____. ______ is an inflammation of the meninges that surround the brain and spinal cord. Swelling of the meninges typically triggers severe headache and neck stiffness.

meningitis Meningitis

The longitudinal vessels reside in the _______ space.

subarachnoid

Recall that the __________ space is found between the arachnoid and the pia mater and contains CSF. The subarachnoid space may be used to introduce _______, ________ and _______. It may also be accessed to obtain a sample of CSF to test for infection or to assess CSF pressure.

subarachnoid antibiotics chemotherapeutic agents anesthetics

The growth of the _______ outpaces that of the _______. The differential growth rates of the vertebral column and spinal cord account for why the _______ extends longer than the termination of the _______ in the adult.

vertebral column spinal cord vertebral column spinal cord

_________ is the outermost layer: meaning 'hard mother', referring to its thick and tough characteristics. The ____ mater forms the _____ (or thecal) sac within the vertebral canal and is separated from the vertebrae by the _______ (or epidural) space.

Dura mater dura dural Dura mater extradural

Also recall that the spinal cord terminates at _____ while the subarachnoid space ends at _____. Lumbar puncture or CSF spinal tap thus can be most safely performed between ________ because at these levels, the subarachnoid space typically contains roots of the cauda equina but does not contain the ______ Notice also that unlike thoracic spinous processes, the lumbar spinous processes ______ overlap, thereby providing good access for passage of a needle. Lumbar flexion (placing the individual in a fetal position) further opens the spacing between lumbar spinous processes. Image-guided lumbar puncture is the safest approach.

L1-L2 S2 L3-4 or L4-5 spinal cord. do not

__________ are the main source of blood supply to the spinal cord. These originate from the R & L _______ arteries. These travel the entire length of the spinal cord: • __ longitudinal anterior spinal artery • ___ longitudinal posterior arteries.

Longitudinal arteries vertebral 1 2

The distal end of the spinal cord tapers into a cone shaped portion called the ________. This is the terminal portion of the spinal cord that typically terminates at vertebral level _____ in the adult.

conus medullaris L1-L2

Venous drainage of the spinal cord is via :

longitudinal veins (anterior and posterior) segmental veins- parallel with segmental arteries

The innermost meningeal layer is the ___________. The ________ ("tender mother") is a delicate layer that attaches directly to the spinal cord, nerve rootlets and subarachnoid vessels. The____ forms denticulate (tooth-like) ligaments, which run longitudinally on either side of the spinal cord and extend laterally as a series of triangular extensions that anchor the spinal cord to the inner surface of the dural sac, limiting spinal cord movement. The ___ also forms the filum terminale (see slide #6).

pia mater pia pia

The spinal cord (and brain) are surrounded and protected by layers of connective tissue called meninges. There are three meningeal layers:

the dura mater, the the arachnoid, and the pia mater.