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24 Cards in this Set
- Front
- Back
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length |
45cm |
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2 swellings |
cervical region lumbar region |
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at the lower end the spinal cord narrows into a |
medullary cone & ends as a terminal filament |
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from the medullary cone upwards the ventral canal contains |
only a dense mass of fibres known as the cauda equina |
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spinal segments |
spinal cord is divided into segments |
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1 segment is part of the spinal cord that gives rise to |
1 pair of spinal nerves |
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how many segments are there in the spinal cord |
31 segments
8 cervical segments 12 thoracic segments 5 lumbar segments 5 sacral segments 1 pair of coccygeal nerves |
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the spinal cord is made up of |
white matter grey matter |
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white matter |
for the funiculi ant, lat and post funiculi are present in the spinal cord these funiculi contain nerve tracts (pathways) AXONS there are NO nuclei of the nervous system |
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grey matter |
organised into horns ant, lat and post horns grey matter is made up of neurons (nerve cells) contains the nuclei of the nervous system |
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nervous plexuses (ventral branches of spinal nerves) |
cervical (C1-C4) brachial (C4-T1) lumbar (L1-L4) sacral (L4-S4) |
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blood supply |
vertebral arteries (2) segmental arteries anterior spinal artery |
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vertebral arteries (2) |
before they unite they give off 2 small posterior spinal arteries which form a network along the posterior surface of the spinal cord
at the level of pyramidal decussation 2 additional branches of vertebral arteries join to form the ant spinal artery which runs along the entire length of spinal cord at the anterior sulcus |
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segmental arteries |
post branches & vertebral arteries give off spinal branches these branches enter through the intervertebral foramina to the spinal cord |
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anterior spinal artery |
gives off sulcocommisural arteries which alternate to the left & right halves of the spinal cord in the cervical & thoracic regions, but divides into 2 branches in the lumbar and sacral regions |
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veins |
1 ant spinal vein 2 post spinal veins open into the epidural venous plexus |
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there are anastomoses between |
post & ant spinal arteries forming a vascular ring (vasocorona) around the spinal cord |
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arteries from this ring radiate into the |
white matter, the grey matter is even more highly vascularised |
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coverings (meninges) - 3 |
1. Dura mater 2. Arachnoidea 3. Pia mater |
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1. Dura mater |
outermost layer separated from vertebral column by epidural space filled with adipose tissue & internal venous plexus |
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2. Arachnoidea |
borders closely to the inner surface of the dura mater forms boundary of the subarachnoid space (filled with CSF) with pia mater between dura mater + arachnoidea - the subdural space which widens into a space in pathological conditions - subdural bleeding |
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3. Pia mater |
contains many blood vessels which penetrate from the surface into the spinal cord denticulate ligament extends on both sides from pia mater to dura mater lig keeps spinal cord in position - floats in CSF |
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function of the spinal cord |
controls sensory, motor + vegetative func's of trunk and extremeties reflexes - both motor and sensory |
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how to obtain a sample of CSF |
lumbar puncture needle placed in subarachnoid space between L3 and L4 of vertebrae |
