Test 1 Flashcards
the boundaries of the IVF :
superior and inferior = pedicles; posterior = z joints; anterior = posterior aspect of body and IVD
list the contents of the IVF:
spinal vein; nerve roots (30-50%), transforaminal ligaments, spinal artery, lymphatic channel, loose areolar and adipose
How does the size and shape of the IVF change when a vertebra subluxates?
posterior and inferior subluxation; IVF becomes irregularly shaped from elliptical shape (normal shape); the alteration of the anterior to posterior dimension will effect the nerve roots
What are the transforaminal ligaments (TFLs)?
Sturdy, dense collagenous bands criss-crossing the IVF; holds the contents of the IVF together
What purpose do TFLs serve?
Divide the IVF into separate compartments surrounding the nerve root; nerve roots are fixed in a constant position
What patterns of TFLs were discussed? Page 10 of the note packet
penis
- What paths through the IVF are specific to each area of the spine?
In the cervical the path is inferior, middle in the thoracic and superior in the lumbar
- Why do nerve roots in each area of the spine have different approaches to the IVF?
idk
- What is the immediate effect of compression on peripheral nerves?
Normal conduction exists prior to the zone of compression and distal to the zone of compression (decrease conduction at compression); a slight variation in conduction velocity exists because there is a reduction of conduction velocity at the site of compression
As little as_____ pressure applied to _____of the nerve root will result in a number of the fibers being blocked and nonconducting; this pressure applied for 15 minutes results in a ___% decrease in conductivity and after 30 min results in a ___% decrease in conductivity
10mm Hg
2.5 mm
25%
50%
amount of pressure required to induce similar deficit in a peripheral nerve compared to a Nerve root is in excess of _____ about if mercury
100mm Hg
How do the nerve coverings figure into the difference in sensitivity of pressure comparing a NR to a PN?
The nerve root is covered by dura mater and very susceptible to the effects of compression; the peripheral nerve is covered by epineurium and perineurium and not very susceptible to compression
How do nerve capillaries differ from those in the rest of the body?
Nerve capillaries are different because they are wider, longer and they have less musculature on the arteriolar side
it is easy to reduce blood flow to ____ ____
nerve capillaries
why are nerve capillaries structured differently?
If the capillaries have to absorb 40mm Hg the pressure every time the heart beats they would burst from the pressure; the arterial system acts as a resistor to the pressure from the heart beat; as the vessels get smaller the pressure is reduced; in the sudden event of an increase in pulse pressure the nerve arterioles are able to absorb and distribute the increase before the capillaries are damaged
What moves blood through the capillary?
Low pressure gradient
What process makes nutrient waste exchange possible?
Simple diffusion
retrograde blood flow
Reverse blood flow
What causes retrograde flow?
The accumulation of fluid
What is the result of retrograde blood flow?
Transport of waste back into the capillaries may increase concentration waste will be increased and may diffuse back into the tissues and act as pro-inflammatory nociceptive irritants
What is the result of chronic compression of a nerve?
When the nerve or IVF are compressed blood begins to collect immediately distal to the compression zone
What anatomical changes happen to a chronically compressed nerve?
Demyelination of the axons; fibrosis of epineurium and alteration of the axons shape
Be able to list ALL nerve roots and their distributions, sensory regions and reflexes
biceps c5, brachioradilis c6, triceps c7, patellar L4, tibialis anterior L5, Achilles S1
Be able to describe the double crush phenomena:
the nerve may be compressed at two or more sites; individual compressions are asymptomatic however both when along the course of a single nerve will result in peripheral nerve symptoms
Winsor’s hypothesis was
minor curvatures of the spine led to autonomic nervous system (sympathetic) malfunction resulting in visceral pathology
Windsor also noted that there was never a case of complete _______ block, where all organs supplied by a sympathetic segment were_____
sympathetic
diseased
o Sympathetic signals can be ______ or _____the segment the nerve exits
above
below