Term
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Definition
Consists of neuronal cell bodies and is
divided into the:
Dorsal horn
Ventral horn
Lateral horn |
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Term
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Definition
Consists of neuronal fibers and is divided into the:
Dorsal funiculus
Ventral funiculus
Lateral funiculus |
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Term
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Definition
Distinct surface indentation present at all spinal cord levels
Related to the anterior spinal artery |
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Term
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Definition
| A less distinct surface indentation present al All spinal cord levels |
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Term
| DORSAL INTERMEDIATE SEPTUM |
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Definition
A surface indentation PRESENT ONLY AT & ABOVE T6
Distinguishes ascending fibers within the GRACILE FASCICULUS (from the lower extremity) from ascending fibers within the CUNEATE FASCICULUS (from the upper extremtiy) |
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Term
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Definition
The end of the spinal cord
Occurs at vertebral level L1 in the adult and L3 in the newborn |
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Term
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Definition
| Consists of dorsal and ventral nerve roots of L2 through Coccygeal 1 spinal nerves traveling in subarachnoid space below the conus medullaris |
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Term
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Definition
Prolongation of the PIA MATTER from the conus medullaris to the end of the dural sac at S2 where it blends with the dura.
The dura continues caudally as the FILUM OF THE DURA MATER (or coccygeal ligament) which attaches to the dorsum of the coccyx bone |
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Term
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Definition
Located between vertebra and dura mater
Space contains fat and INTERNAL VERTEBRAL VENOUS PLEXUS |
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Term
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Definition
| Tough outermost layer of the meninges |
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Term
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Definition
| Located between dura mater and arachnoid |
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Term
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Definition
| Filmlike, transparent layer connected to pia mater by TRABECULATIONS |
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Term
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Definition
| Located between arachnoid and pia mater and filled with CSF |
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Term
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Definition
Thin layer closely applied to spinal cord
Has lateral extensions called DENTICULATE LIGAMENTS that attach to the dura mater and suspend spinal cord in dural sac |
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Term
| ANTERIOR SPINAL ARTERY & POSTERIOR SPINAL ARTERIES |
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Definition
Only 1 anterior spinal artery
Arises from vertebral arteries
Runs in the anterior median fissure
Gives rise to SULCAL ARTERIES which supplies VENTRAL 2/3 of spinal cord
2 Posterior Spinal Arteries
Arise from either vertebral arteries or posterior inferior cerebellar arteries
Supplies the DORSAL 1/3 of spinal cord
Both anterior and posterior supply only short superior part of cord
Remainder of cord depends on SEGMENTAL MEDULLARY ARTERIES & RADICULAR ARTERIES |
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Term
| ANTERIOR & POSTERIOR MEDULLARY SEGMENTAL ARTERIES |
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Definition
Arise from spinal branches of ascending cervical, deep cervical, vertebral, posterior intercostal,and lumbar arteries
Occur irregularly in place of radicular arteries
Are located mainly in cervical and lumbosacral spinal enlargements
Medullary are "large radicular arteries" that connect with anterior and posterior spinal arteries--radicular arteries do not connect |
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Term
| GREAT ANTERIOR SEGMENTAL MEDULLARY (OF ADAMKIEWICZ) |
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Definition
Generally arises on left side from posterior intercostal artery or lumbar artery
Enters vertebral canal through intervertebral foramen at lower thoracic or upper lumbar level
Clinical importance: makes major contribution to anterior spinal artery and lower part of spinal cord
If ligated during resection of abd. aortic aneurysm, anterior spinal artery syndrome may result. Symptoms: paraplegia, impotence, bladder and bowel incontinence, loss of pain and temperature. Vibration and proprioception are preserved. |
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Term
| ANTERIOR AND POSTERIOR RADICULAR ARTERIES |
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Definition
| Small and supply only dorsal and ventral roots of spinal nerves and superficial parts of gray matter. |
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Term
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Definition
Strips of skin extending from posterior midline to anterior midline
Are supplied by sensory branches of dorsal and ventral rami of a single spinal nerve |
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Term
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Definition
Done to withdraw CSF or inject anesthetic
Needle in above or below spinous process of L4
Needle passes through: skin, superficial fascia, supraspinous ligament, interspinous ligament, ligamentum flavum, epidural space containing internal vertebral venous plexus, dura mater, arachnoid, subarachnoid space containing CSF. Pia mater is not pierced. |
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Term
SPINAL ANESTHESIA
(SPINAL BLOCK OR SADDLE BLOCK) |
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Definition
Inject anesthetic in subarachnoid space
May be used during childbirth
Sensory nerve fibers for pain from uterus travel with:
Pelvic splanchnic nerves (parasympathetic) to S2-4 from the cervix(may be responsible for referred pain to gluteal region and legs)
Hypogastric plexus and lumbar splanchnic nerves (sypathetic) to L1-3 from the fundus and body of uterus and oviducts (may be responsible for referred pain to back)
Anesthesia up to nerve @ T10 to block pain for vaginal childbirth and nerve @ T4 for C-section
Pregnant women require smaller dose due to compression of internal vertebral venous plexus engorged with blood from pregnant uterus compressing IVC
Complications: hypotension(sympathetic blockade and vasodilation), respiratory paralysis (phrenic nerve involved from high spinal block), spinal headache(due to CSF leakage) |
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Term
| LUMBAR EPIDURAL ANESTHESIA |
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Definition
Injected into epidural space
May be used during childbirth
Complications:
respiratory paralysis (high spinal block if dura and arachnoid punctured and usual dose injected into subarachnoid by mistake), CNS toxicity(slurred speech, tinnitus, convulsions, cardiac arrest) due to anesthetic in internal vertebral venous plexus (IV injection instead of epidural) |
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Term
| ANTERIOR SPINAL ARTERY OCCLUSION |
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Definition
Damage to lateral corticospinal tracts, lateral spinothalamic tracts, hypothalamospinal tracts, ventral gray horns, corticospinal tracts to sacral parasympathetic centers at S2-4.
Clinical findings: bilateral spastic paresis with pyramidal signs below lesion, bilateral loss of pain and temperature below lesion, bilateral Horner syndrome, bilateral flaccid paralysis, loss of voluntary bowel and bladder control. |
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Term
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Definition
Central cavitation of cervical spinal cord of unknown etiiology
Damage to ventral white commissure involving decussating lateral spinothalamic axons and ventral gray horns
Clinical findings: bilateral loss of pain and temperature and flaccid paralysis of intrinsic muscles of hand |
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Term
COMPLETE SPINAL CORD INJURY (SCI)
Transection of the spinal cord |
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Definition
Loss of sensation and motor function below level of lesion. 2 types:
Paraplegia (paralysis of lower limbs) if transection between cervical and lumbar enlargements of SC
Quadraplegia(paralysis of all 4 limbs)if transection above C3. May die quickly due to respiratory failure if phrenic nerve compromised |
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Term
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Definition
Ameliorated somewhat by rapid surgical intervention.
3 situations leading to incomplete SCI:
concussive blow
anterior spinal artery occlusion
penetrating blow (Brown-Sequard syndrome) |
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Term
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Definition
Hypotension in acute setting
ileus(bowel obstruction due to lack of motility)
renal stones
pyelonephritis
renal failure
deep venous thrombosis
Methylprednisolone beneficial if given within 8 hours of injury |
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Term
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Definition
Malignant, midline, lobulated mucoid tumors arise from remnants of embryonic notochrod
Usually occur in sacral(most common) or clival region.
Have histoligic features including physaliphorous(bubble-bearing) cells with mucoid droplets in cytoplasm |
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Term
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Definition
account for 70% of all neurologic tumors
Typically arise from astrocytes and composed of cells with elongated or irregular, hyperchromatic nuclei and eosinophilic glial fibrillary acidic protein(GFAP)- positive cytoplasm
Glioblastoma multiforme(GBM) most common primary brain tumor in adults (men 40-70)
Highly malignant and pursue rapid fatal course
Common site is frontal lobe, which commonly crosses corpus callosum, producing a butterfly appearance on MRI |
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Term
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Definition
90% are benign
Arise from arachnoid cap cells of arachnoid villi of meninges and found at skull vault, sites of dural reflection(falx cerebelli, tentorium cerebelli), optic nerve sheath, and choroid plexus.
Most common in women
May increase in size during pregnancy
Have an increased incidence in women taking postmenopausal hormones, assoc. with breast cancer,suggesting potential involvement of steroid hormones. |
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Term
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Definition
Benign
Well-circumscribed, encapsulated tumors that arise from Schwann cells located on cranial nerves, spinal nerve roots(present as dumb-bell-shaped tumors protruding through intervertebral foramen) or spinal nerves.
Most common intracranial site is cerebellopontine angle with involvement of cranial nerve VIII(acoustic neuroma), where expansion of tumor results in tinnitus and sensorineural deafness.
Multiple schwannomas may occur assoc. with neurofibromatosis type II. |
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Term
| DORSAL COLUMN - MEDIAL LEMNISCAL SYSTEM |
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Definition
Pathway for discriminitve touch, vibration, and proprioception
Signal travels up same side of the cord then crosses over at the medulla |
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Term
| LATERAL SPINOTHALMIC TRACT (ANTERIOLATERAL SYSTEM) |
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Definition
Pathway for pain, temp. and crude touch
Signal travels to the opposite side of the spinal cord and up |
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Term
DESCENDING MOTOR
LATERAL CORTICOSPINAL TRACT |
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Definition
Cortex to spinal cord
Signal crosses over at lower part of medulla
Same side they innervate is the opposite side of the brain where they originate
Impulses to motor nerves and muscles |
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Term
ANTERIOR SPINAL ARTERY SYNDROME
(ADAMKIEWICZ ARTERY) |
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Definition
Adamkiewicz artery makes major contribution to anterior spinal artery and lower part of SC
If ligated during resection of abd. aortic aneurysm, anterior spinal artery syndrome may result
Symptoms: paraplegia, impotence, bowel and bladder incontinence, loss of pain and temp. but vibration and proprioception sensation is preserved |
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