Test 3 - 10/7 lecture Flashcards
Cerebral circulation does a good job _____
auto regulating
Running longitudinally along the spine we have ____ main arteries. They are called _____
- (1) Anterior spinal artery
(2) Posterior spinal arteries
The anterior spinal artery is located within the _____
anterior median fissure
The superior portion of the posterior arteries get their blood supply from?
mainly vertebral and (anterior inferior and posterior) cerebellar arteries.
The three main cerebellar arteries are
Superior cerebellar artery
anterior inferior cerebellar artery
posterior cerebellar artery
Radicular arteries are
Branches of the intercostal arteries
Radicular arteries feed into
the anterior or posterior spinal arteries
______ arteries are found in the neck and are the rear posterior source of blood going into the COW
Vertebral
Intercostal arteries are found _______ and we have _____ sets of them
Between each of our ribs.
12 sets.
What is the source of blood supply for the spinal arteries in the lower portion of the cord?
Primarily intercostal arteries that branch into radicular arteries.
What does the typical branching of radicular arteries is _____ and will feed into the spinal cord every ____ vertebral levels
Irregular
5 or 6 levels
What are the three different names for the feed arteries?
Radicular (our primary focus)
Medullary
Segmental
Sometimes used in combination.
The posterior segmental medullary artery is what?
The feed artery that feeds into the posterior spinal artery.
The arteries found on the outer surface of the cord that are not continuous
Coronal arteries “crown”
What is different between the arteries in the spine vs the brain?
The brain (COW) has collateral circulation, if one part gets blocked blood will still move through. The spinal arteries dont have that feature
The difference between the posterior spinal vein and the posterior spinal arteries is what?
The vein is midline, the arteries are on each side
True/False. Veins typically follow the same pattern that arteries do.
True
Intercostal arteries come off of the _______ and majority will wrap around the sides of the rib cage.
Thoracic aorta
From the Thoracic aorta what route would arterial blood take to feed the anterior spinal artery
1- Intercostal artery
2- Dorsal branch
3- Spinal branch
4-Anterior radicular artery
5- Anterior spinal artery
At every level of the spinal cord, regardless of having radicular arteries we will have a
Spinal branch
The spinal branch sits on top of
dorsal root ganglion
Intercostal arteries are responsible for
keeping the ribcage healthy and perfused
Artery that perfuses the small intestines
mesenteric artery
When clamping the aorta, we worry about anything _____ to the clamp
distal/inferior
The anterior spinal artery perfuses _______ of the spinal cord
75%
Both posterior spinal arteries perfuse _____ of the cord combined
25%
There are usually _____ feed vessels to the anterior spinal artery in the cervical potion
2
Usually _____ feed vessels in to the anterior spinal artery in the thorax
2-3
Usually ______ feed vessels into the anterior spinal artery in the lumbar potion
1-2
Typically the posterior spinal arteries have _______ feed vessels than the anterior spinal artery
more
The arterial flow of the lower 2/3 of the anterior spinal cord is fed by the
Great Radicular Artery (GRA)
(Artery of Adamkiewicz)
The most common place to find the Great Radicular artery would be the
Left side of T10
A typical range for the location of the great radicular artery (75% of patients)
T9-T12
What are the possible levels that the greater radicular artery could be found?
T5-L5
Surgery requiring an aortic clamp above the level of the artery of Adamkiewicz puts the patient at a much greater risk of
paralysis or loss of motor function
Surgery requiring aortic clamping blow the GRA would?
likely have less issues
Normal perfusion pressure for the cerebral circulation is typically
50-150mmHg
Perfusion pressure is measured by
taking MAP - ICP
Normal healthy patient ICP should be
10 mmHg
Aortic cross clamping will increase your CSF pressure that surrounds the spinal cord ______
~10 mmHg
If we have low MAP and our ICP is doubled following aortic cross clamp we would worry about what? What could we do to help?
The pressure being so high that the cord isn’t being perfused.
We could put in a drain to relieve some of the pressure
The damage of ischemia reperfusion injury is done by
Excess Oxygen levels
A typical defense mechanism to keep oxygen induced damage in check
antioxidants
Oxidative potential of oxygen in the immune system?
immune system uses oxygen to destroy stuff
spinocerebellar tracts
carry information about muscle or tendon stretch to the cerebellum
The cerebellum helps us
coordinate complicated movements (walking)
We have 4 sections of the spinocerebellar tracts. What are they called and what kind of information do they carry?
1- Posterior/Dorsal Cerebellar tract (located bilaterally on the lateral portions of the cord)
2- Anterior/Ventral Cerebellar tract (located bilaterally on the lateral portions of the cord)
They carry sensory information to the cerebellum
The anterior/ventral spinocerebellar tract is responsible for information about
The level of motor activity at that level of the spinal cord
The anterior/ventral spinocerebellar tract ascends and passes through the
Superior Cerebellar Peduncle
The posterior/dorsal spinocerebellar tract is responsible for information about
tendons and muscle spindle (stretch sensors)
The posterior/dorsal spinocerebellar tract ascends and passes through the
Inferior cerebellar peduncle
The two categories of things that can cause us pain are
Chemical and mechanical
Examples of chemical that can cause pain (9)
- Bradykinin
- Serotonin
- Histamine
- K
- ACh
- H+
- Proteolytic enzymes
- Ischemia/muscle spasm
- PG’s
How do PG’s relate to pain?
not directly painful but augments pain
How does ischemia relate to pain?
build up of metabolic waste products (lactic acid)
pain threshold
amount of stimulation required before a person experiences the sensation of pain
Chronic pain will have what effect on pain threshold?
It will typically reduce pain threshold, meaning it will be easier to stimulate a pain response than it was before.
In regards to pain, if we have a lower threshold potential it would be _____ to stimulate and we would experience _____ pain. If we have a higher threshold potential it would be ______ to stimulate and we would experience ______ pain.
easier; more
harder; less
Visceral pain
Internal organ pain transmitted by the autonomic nerve bundles.
Visceral pain is difficult to ________ and is usually ________
localize; referred
Parietal pain is pain of
connective tissue
Parietal pain is highly
localized
Why do we have poor localization of visceral pain?
Because organs lack tactile sensors
The liver and the soft tissue of the lungs do not
have pain sensors
Parietal pain is described as being ____ and uses ____ fibers
sharp. A delta
Visceral pain is described as being ____ and uses ____ fibers
dull/achy. C
Appendix can have _____ pain.
Dual
If you are having an appendicitis attack and have pain in the RLQ this is a ______ pain
Parietal pain (it is localized to the actual location of the tissue)
If you are having and appendicitis attack and have pain above your umbilicus this is a ______ pain
Visceral pain (it is referred to a site other than the actual site of the painful stimuli)
Why is visceral appendix pain higher up? Where is it located?
The visceral pain fibers are routed up to the sympathetic chain and gets fed into autonomic ganglia and then ascends 2-3 levels and then enters cord.
T10/umbilicus
Because it is not localized well visceral pain will not decrease via ______ like other more localized painful stimuli can be.
lateral inhibition
Referred pain: Ischemia in the heart would cause pain in ____. Bad heartburn could cause pain in _____. Kidney pain is referred to _____
L arm.
higher than umbilical region
Lower back
Slow pain signals that terminate in the brain stem make up the
reticular formation
The limbic system is made up of what deep brain structures? (3)
Amygdala (the MVP)
Hypothalamus
Cingulate gyrus
Cingulate gyrus is located
superior to the corpus callosum
Motor neurons are typically _______ fibers
A-alpha
What kind of fibers are used in the autonomic nervous system
Non or Lightly myelinated fibers
What part of the cerebral cortex is involved in slow pain?
Cingulate Gyrus
Muscle spindle and tendon feedback is likely sent on fibers that can be described as
Large and myelinated
The DCML pathway typically has neuronal fibers ranging from
A-alpha (A-beta) to A-gamma
What type of fiber is involved in lateral inhibition
A-beta
Aching/dull/nausea is sent via ___ fibers
C fibers
Fast pain usually travels via
A-delta fibers
