Spinal Cords and Spinal Nerves

somatic sensory (SS), visceral sensory (VS), visceral motor (VM), and somatic motor (SM)

Four zones are evident within the gray matter

Dura Mater

It is directly attached to the inner surface of the bones of the cranium and to the very end of the vertebral cavity.

Spinal Cord

It is the connection center for the reflexes as well as the afferent (sensory) and efferent (motor) pathways for most of the body below the head and neck.

Ventral Root

It is the efferent motor root of a spinal nerve.

Filum Terminale

It is the fibrous extension of the pia mater; anchors the spinal cord to the coccyx.

Conus Medullaris

It is the terminal portion of the spinal cord.

Intercostal Nerves

Spinal nerves T2-T12 do not enter into the plexuses.

Lumbar enlargement

T9:T12 supply lower limbs

Referred Pain

The brain is poor at interpreting visceral pain and instead interprets it as pain from the somatic area of the dermatome.

anterior root

Ventral Root is also called the:

occulta

What the word ___________ means; it is hidden spina bifida.

Spinal Cord

a long, fragile tube like structure that begins at the end of the brain stem and continues down almost to the bottom of the spine.

Dura Mater

a tough outer covering. The name comes from the Latin for "tough mother" to represent its physically protective role.

Blood vessels

along surface of spinal pia mater within subarachnoid space

Arachnoid

emerges into the dural sinuses as the arachnoid granulations, where the CSF is filtered back into the blood for drainage from the nervous system.

Paired denticulate ligaments

extend from piamater to dura materstabilize side-to-side movement

Ansa cervalis

infra and geniohyoid muscles

Musculocutaneous nerve

innervates anterior skin of upper arm and elbow flexors

Radial nerve

innervates dorsal aspect of the arm and extensors of the elbow, wrist, and fingers, abduction of thumb

Brachial Plexus and Axillary nerve

innervates the deltoid muscle and shoulder, along with the posterior aspect of the upper arm.

Ulnar nerve

innervates the medial aspect wrist and finger flexors.

Median nerve

innervates the middle elbow, wrist and finger flexors, adducts the thumb.

Multiple Sclerosis

is a disease of the central nervous system, and is the most common neurolgical disorder in young adults. It is a chronic disease that is often disabling, but isn't fatal.

Plexus

is an interconnection of fibers which form new combinations as the "named" or peripheral nerves.

Intercostal Nerves

✘ Anterior ramus innervates intercostal muscles, abdominal muscles and overlying skin

Cervical nerves

Are named for inferior vertebra.

Caudaequina

(horse tail) nerves below L2

Flaccid Paralysis

-Lower motor neurons are damaged and impulses do not reach muscle

Spastic Paralysis

-Spinal neurons remain intact and muscles are stimulated irregularly

Flaccid Paralysis

-There is no voluntary or involuntary control of muscles

dura mater, arachnoid mater, pia mater

3 layers of meninges

Spinal Nerves

31 pairs attach to the cord by paired roots.

Meninges

A formation of a cyst—a fluid-filled sac of the connective tissues that cover the spinal cord.

Arachnoid Mater

A membrane of thin fibrous tissue that forms a loose sac around the CNS and it looks like a spider web, giving this layer its name.

Meninges

A series of membranes composed of connective tissue that covers outer surface of the CNS.

Dura Mater

A thick fibrous layer and a strong protective sheath over the entire brain and spinal cord. It is anchored to the inner surface of the cranium and vertebral cavity.

Pia Mater

A thin fibrous membrane that follows the convolutions of gyri and sulci in the cerebral cortex and fits into other grooves and indentations. It is directly adjacent to the surface of the CNS.

scoliosis and osteoporosis

Abnormal spine growth and bone deterioration may cause:

Meninges

Acting with cerebrospinal fluid to protect the CNS from mechanical damage.

paralysis or quadriplegia

Advanced SM can cause:

Superior Vertebra

All other nerves are named for :

Dorsal Root

Also known as the posterior root.

Cervical enlargement

C4:T1 supply upper limbs

peripheral nerves

Each plexus gives rise to new combinations of fibers as the:

Dorsal and ventral roots

Fuse laterally to form spinal nerves.

Syringomyelia

Is a chronic spinal cord disorder that forms before birth or as a result of an accident, tumor or disease. The condition causes fluid to flow into the spinal cord, causing a cyst that grows and damages nerve fibers.

Arachnoid Trabeculae

Is a thin, filamentous mesh that isbeneath the arachnoid.

Referred Pain

Is caused when the sensory fibers from an internal organ enter the spinal cord in the same root as fibers from a dermatome.

Spina Bifida Occulta

Is the mildest because the vertebral bones do not fully surround the spinal cord, but the spinal cord itself is not affected.

Pia Mater

It comes from the Latin for "tender mother," Suggesting the thin membrane is a gentle covering for the brain.

Dura Mater

It encloses the entire CNS and the major blood vessels that enter the cranium and vertebral cavity.

Spinal Segment

It gives rise to one spinal nerve

Spinal Cord

It is also the center for reflexes, such as the knee jerk reflex.

Lou Gehrig's Disease

Linked to MALFUNCTIONING GENES for glutamate transporter and/or superoxide dismutase

spino

Most sensory tracts names begin with ________, indicating origin in the spinal cord, and their name will end with the part of the brain where the tract leads.

Spina Bifida Occulta

No functional differences may be noticed

Intercostal Nerves

Posterior ramus innervates deep back muscles and skin of the posterior thorax

Meninges

Provide a supportive framework for the cerebral and cranial vasculature.

Denticulate Ligaments

The delicate shelves of pia mater; attach the spinal cord to the vertebrae

Poliomyelitis

The destruction of the anterior horn motor neurons by the poliovirus.

Arachnoid Mater

The middle layer of the meninges, named for the spider-web-like trabeculae between it and the pia mater.

Dorsal Ramus

The posterior (or dorsal) branches (or divisions) of the spinal nerves are, as a rule, smaller than the anterior divisions.

Spinal Cord

The spinal cord begins at the brainstem and ends at about the second lumbar vertebra.

31

There are (?) pairs of spinal nerves

cervical plexus, brachial plexus, Lumbar plexus, sacral plexus

There are four voluntary plexuses

Dorsal Ramus

They are also referred to as the dorsal rami.

Dorsal Ramus

They are directed backwards and—with the exceptions of those of the first cervical, the fourth and fifth sacral, and the coccygeal—divide into medial and lateral branches for the supply of the muscles and skin of the posterior part of the trunk.

motor

Tracts whose names begin with a part of the brain are _______.

Trabeculae

are found in the subarachnoid space, which is filled with circulating CSF.

Dermatomes

are somatic or musculocutaneous areas served by fibers from specific spinal nerves.

corticospinal tract

begins with fibers leaving the cerebral cortex and travels down toward motor neurons in the cord.

Cauda Equina

collection of nerve roots at the inferior end of the vertebral canal

Spinal Cord

consists of nerves that carry incoming and outgoing messages between the brain and the rest of the body.

Spinal Nerves

contain both sensory and motor fibers, as do most nerves.

Ventral Ramus

contains nerves that serve the remaining ventral parts of the trunk and the upper and lower limbs carrying visceral motor, somatic motor, and sensory information to and from the ventrolateral body surface, structures in the body wall, and the limbs.

Arachnoid

defines a sac-like enclosure around the CNS.

Posterior median sulcus

divides posterior funiculi

Paralysis

loss of motor function

Ventral Half

motor roots

White Matter

myelinated axons of motor & sensory

Grey Matter

nerve cell bodies motor & interneurons

Lou Gehrig's Disease

neuromuscular condition involving destruction of anterior horn motor neurons and fibers of the pyramidal tract

Spastic Paralysis

only upper motor neurons of the primary motor cortex are damaged

Pia Mater

outer surface of the CNS is covered in the thin fibrous membrane of the pia mater. It is thought to have a continuous layer of cells providing a fluid-impermeable membrane.

Filumterminale

pia mater anchors cord to coccyx

Dorsal Half

sensory roots and ganglia

Anterior median fissure

separates anterior funiculi

Flaccid Paralysis

severe damage to the ventral root or anterior horn cells

Cervical and lumbar enlargements

sites where nerves serving the upper and lower limbs emerge

Occipital, auricular and supraclavicular

skin-head/neck

Epidural space

space between the vertebrae and the dural sheath filled with fat and a network of veins

Conusmedullaris

tapers off to end at L1-L2

Cervical Plexus

the Plexuses phrenic nerve travels through the thorax to innervate the diaphragm.

Dorsal Root

the afferent sensory root of a spinal nerve.

Myelomeningocele

the meninges protrude and spinal nerves are involved, and therefore severe neurological symptoms can be present.

Meningocele

the meninges protrude through the spinal column but nerves may not be involved and few symptoms are present, though complications may arise later in life.

occulta, meningocele, and myelomeningocele.

three classes of this disorder

Paraplegia

transection between T1 and L1

Quadriplegia

transection in the cervical region

spinothalamic tract

travels from the spinal cord to the thalamus.