Module 5, Year 1 - Neurophysiology & UCSC, Mechanoreceptive Dysafferentation Flashcards
The tectorial membrane is taut at…
15 degrees flexion, 20 degrees extension
The apical ligament is taut at…
20 degrees flexion, 30 degrees extension
The anterior atlantodentate ligament is taut at…
Less than 10 degrees rotation
Which of the following ligaments connect the occiput to the anterior tubercle of the atlas?
a) anterior longitudinal ligament
b) Lateral atlanto-occipital membrane
c) Anterior atlanto-occipital membrane
d) Posterior longitudinal ligament
e) Tectorial ligament
c) Anterior atlanto-occipital membrane
- The tectorial membrane contains type 3 collagen fibres which have a higher elastic fiber component. Due to this feature, the tectorial membrane begins to limit flexion and extension at the CCJ at which degrees of movement respectively?
a. 20 degrees of flexion, 15 degrees of extension
b. 15 degrees of flexion, 20 degrees of extension
c. 10 degrees of flexion, 15 degrees of extension
d. 5 degrees of flexion, 10 degrees of extension
e. 20 degrees of flexion, 10 degrees of extension
b. 15 degrees of flexion, 20 degrees of extension
- Which of the following is true regarding chiropractic and stroke?
a. Many people will seek help for headaches and neck pain from their doctor or chiropractor
b. A stroke may present with unilateral neck pain and headache, often described as the worst headache of their life
c. Strains sustained by the vertebral artery during SMT are approx. 1/9th of the strain at mechanical failure
d. The vast majority of strokes related to cervical SMT occur in the vertebra-basilar, specifically between C1 and C2
e. All of the above
e. All of the above
Which of the following statements is false?
a) No significant changes in VA blood flow have been overserved in healthy young adults
b) No significant associated between loss of cervical lordosis and decreased VA hemodynamics have been found
c) 30 degrees of cervical rotation causes contralateral VA kinking
d) 45 degrees of cervical rotation causes ipsilateral VA kinking
e) The vertebral artery becomes compresed with 10 degrees of extension at the atlanto-axial joint
b) No significant associated between loss of cervical lordosis and decreased VA hemodynamics have been found
[A significant association has been found between a loss of lordosis and reduced VA diameter, flow volume, and peak systolic velocity]
Which of the following statements is false?
a) The transverse ligament is proatantal derivative and is first seen in the embryo when it is 27mm long
b) The anterior atlantodental ligament is found approx. 81% of people and is located below the fovea dentis and the dens
c) The anterior atlantodental ligament become taut with C1/C2 rotation prior to the alar ligaments
d) Only flexion will produce tension in Barkow’s ligament
e) The cruciate ligament has three parts
d) Only flexion will produce tension in Barkow’s ligament
Barkow’s ligament produces tension with EXTENSION
The three parts of the cruciate ligament are the transverse ligament, cranial crus, and caudal crus
- Which of the following is a function of the alar ligaments?
a. Check rotation (aka check ligaments)
b. Left alar ligament controls right axial rotation
c. The superior part of the contralateral alar ligament becomes taught in lateral flexion
d. All of the above
e. None of the above
d. All of the above
What is the tensile strength of the following ligaments: Transverse ligament Capsular ligament Alar ligament Tectorial membrane Lateral atlanto-occipital ligament
Transverse - 400N Capsular - 300N Alar - 200N Tectorial - 80N Lateral atlanto-occipital - 40N
Which of the following is true regarding the accessory atlantoaxial ligament?
a) Maximally taut at 5-10 degrees of extension
b) It is found in 92% of specimens
c) It is lax in flexion
d) It is located between the occiput, atlas, and axis
e) It is taut with rotation of the head at 15-20 degrees
d) It is located between the occiput, atlas, and axis
It is maximally taut at FLEXION.
It is found in 100% of specimens.
It is lax in EXTENSION.
It is taut with rotation of the head at 5-8 degrees.
The tectorial membrane are made of what kind of tissue?
Type 3 collagen
Describe Type 1 Mechanoreceptors
Slow adapting, ruffini, low threshold
Describe Type 2 Mechanoreceptors
Low threshold, fast adapting, pascini corpuscles
Describe Type 3 Mechanoreceptors
High threshold, slow adapting, golgi tendon
Describe Type 4 Mechanoreceptors
High threshold, fast adapting, nociceptors
Why might obliquus muscles have higher muscle spindle concentration than the rectus capitis?
Possibly due to the limited ROM at C0-C1 joint complex and greater ROM at C1-C2. Either way, all suboccipital muscles have a lack of golgi tendon organs and are not designed for movement; they instead relay information about the joint position
What is clinically significant about forward head carriage?
For every inch forward, it adds an extra 10lbs on the head
A fibrous capsule surrounds the occipital condyles and the atlas superior facets, this capsule is reinforced by what ligaments?
Oblique bands called the lateral antlanto-occipital ligaments (the lateral bands of the atlanto-occipital membrane)
They are continuous with the articular capsule
What are the connecting points for the anterior atlanto-occipital membrane?
The anterior foramen magnum to the superior portion of the atlas anterior tubercle
What ligament strengthens the anterior atlanto-occipital membrane?
Its strengthened by the ANTERIOR LONGITUDINAL LIGAMENT which runs from the basilar portion of the occipital bone, atlas anterior arch and all vertebral bodies and discs before ending at the anterior superior sacrum. It widens as it descends.
Name the origin and insertion of the tectorial membrane.
Continuation of the PLL from cranial base (clivus) to the body of the axis, but NOT to the dens
Is the tectorial membrane taught in both flexion and extension of the AA joint?
Yes, flexion at 15 degrees and extension at 20 degrees
This ligament helps stabilize the skull on the cervical spine posteriorly and attaches
to the EOP, the posterior atlas tubercle and the spinous processes of C1-C7.
Ligamentum nuchae (or nuchal ligament)
The C1-2 articulation is formed by how many joints?
3 - 2 lateral atlanto-axial joints and 1 anterior arch and dens
This membrane attaches from the inferior atlas posterior arch to the superior lamina of C2?
Ligamentum flavum
Are the fibrous capsules surrounding the lateral C1-C2 joints thick and firm or thin
and loose?
Thin and loose to allow for the large amount of rotation between C1-C2
A posterior ponticle, or arcuate foramen, is the calcification of what ligament?
Posterior atlanto-occipital ligament where it arches over the vertebral artery
This membrane connects to the posterior margin of the foramen magnum to the superior margin of the atlas posterior arch?
Posterior atlanto-occipital membrane
The vertebral artery pierces which membrane when it reaches the atlas?
The posterior atlanto-occipital membrane
It then pieces the dura before joining the contralateral VA to form the basilar artery.
How is the pain described by some experiencing a vertebral artery dissection?
Sudden onset of the worst unilateral headache and neck pain person has ever experienced.
T/F: patients with VAD commonly present with neck pain or headaches and hence
seek chiropractic and medical care. VAD’s can occur spontaneously and are not necessarily CAUSED by the practitioners intervention.
True
What does “post hoc, ergo propter hoc” mean?
“After this therefore caused by this”… In regards to chiropractic’s relationship to stroke, this is a Fallacy.
Correlation does not necessarily mean causation.
T/F: The American heart association and American stroke association found a significant link between chiropractic adjustments and stroke.
False, position paper in SPINE, January 2008, found insufficient evidence. There is a correlation because people with VAD symptoms frequently visit their chiropractor or MD for help. In fact, they found that there was a stronger association between stroke and visits to the MD.
Cassidy, Euro Spine Journal 2008, though these were strokes in progress and the people went their chiropractor or MD for acute care due to the pain and hence the correlation between a visit to the chiropractor or MD and stroking out.
What lining of the artery is most affected in VAD?
Tunica media and aventitia (not intimia)
T/F: The strains from CMT are equal to the strains from cervical rotation.
False, the strains from CMT are 1/9th the strain from normal C-rotation.
According to the JMPT 2002, vertebral arteries can be stretched 1.5x their normal resting length before mechanical failure.
Normal rotation puts more strain on the soft tissue structures than CMT.
Whats
the diameter of the VA?
Approximately 4.5mm with the left slightly greater than the right.
Fun fact, the right jugular vein is larger than the left.
How much extension of the Atlanto-axial joint before compression of the VA occurs?
Approximately 10 degrees
T/F: 30 degrees of AA rotation causes the contralateral VA to kink.
True
T/F: 45 degrees of AA rotation causes the ipsilateral VA to kink.
True
List the 5 Ds And 3 Ns of a stroke.
Dizziness, drop attacks, diplopia, dysarthria, dysphagia
Ataxia
Numbness, Nausea, Nystagmus
T/F: For those who had experienced VAD, on follow up 50% had new complaints of upper neck pain and hemi-cranial pain. Described as throbbing, steady, sharp, thunderclap headache.
True
How many deaths to medical errors?
98,000 to 180,000 per year accodring to Leape, JAMA
NSAIDS cause what deadly complications and at what rate?
1 in 1,2000 estimated from gastroduodenal complications and end stage renal disease for taking them for two months.
According to Dabbs, JMPT 1995, chiropractic care in comparison is 700x safer.
Journal of Rheumatology report 16,500 die each year from NSAIDS vs 16,685 each year from HIV.
NSAIDS increased risk of pancreatic cancer.
Liver failure from Tylenol (in cold and flu meds).
Where is the anterior atlantodental ligament?
Between the base of the anterior dens to the posterior aspect of the anterior arch of atlas. Some 38% have connection to the atlanto-occipital membrane.
Becomes taut with approximately 10 degrees of atlantoaxial rotation.
Taut before alars.
Where is Barkow’s ligament and what position of the AO joint causes tension?
Medial aspect of the occipital condyles (left and right) just anterior to the alar attachments.
Extension is the only movement that affects Barkows.
Because its ANTERIOR to the DENS > 75% have attachments to the anterior AO-membrane.
Tensile strength 28N or 6lbs.
What are the 3 components of the CRUCIATE/ CRUCIFORM (cross) LIGAMENT?
Transverse Ligament
Cranial Crus
Caudal Crus
Which two ligaments make up the “longitudinal bands” of the cruciate ligament?
Cranial and caudal crus
What are the attachments of the ALAR LIGAMENTS “check ligaments” and what motion do they check?
Tip of dens to medial side of occipital condyles (atlas sometimes depending on the research)
Checks rotation and lateral flexion of the C0-C1 and C1-C2 joints
Right lateral flexion and right rotation is checked by which ALAR LIGAMENT?
Left alar
Where is the APICAL LIGAMENT and what motions does it restrict?
Tip of dens to foramen magnum (for 80% of people).
Apical is taut in 20 degrees flexion and 30 degrees of extension.
Tectorial membrane is taut in 15 degrees flexion and 20 degrees extension. It can withstand 80N before tearing (about 18lbs).
Which ligament in the CCJ has the greatest tensile strength?
Transverse ligament 400N (90lbs)
Which are stronger, alar ligaments or capsular ligaments?
Capsular ligaments - 300N (67lbs)
Alar withstands only 200N (45lbs)
Which is stronger, alar ligaments or tectorial membrane?
Alar ligaments - 200N (45lbs)
Tectorial membrane only withstands 80N (18lbs)
What ligament attaches from the posterior body of C2 to C0/C1 joint capsule.
Accessory atlantoaxial ligament
Its taut in 10 degrees of flexion and 5-8 degrees of rotation
What ligament is immediately posterior to the rectus capitus lateralitis? Where does it insert?
Lateral atlanto-occipital ligament - 40N (9lbs)
From transverse process of the atlas to the jugular process of occipital bone (the posterior aspect of the jugular foramen)
Vertebral artery is posterior and jugular foramen anterior.
The LAO was found in intimate contact with the vertebral artery posteriorly and with the contents of the jugular foramen anteriorly.
Posterior to the rectus capitus lateralis.
Fully taut at 8 degrees of left and right lateral flexion. Partial tightness in rotation.
Lax in flexion and extension which is probably why its not often torn in whiplash flex/ext trauma.
What ligament is similar to Barkows in its insertions, but on the POSTERIOR side of the dens?
Transverse occipital ligament
Its superior to the transverse ligament.
What membrane lays over the CO/C1/C2 ligament complex and is continuous with the PLL?
Tectorial membrane
What type of MRI would be needed to reveal damage to the Alar ligaments? And what are the best views?
Sagittal and coronal proton density weighted MRI views
From Rosa: on both T1 and T2 images, what color are damaged ligaments?
White = damaged Black = healthy
What position of the head at time of impact, predisposed the occupant to alar ligament damage?
Head in rotation, as alar ligaments are “check ligaments” for rotation
T / F : high signal changes of the alar and transverse ligaments are common in WAD2 and 3 and are unlikely to represent age-dependent degeneration.
True
T/F : Ligament damage is not permanent.
False, whiplash trauma can cause permanent damage to the UC ligaments, especially the alars which check rotation.
T/ F : Whiplash patients have a larger number of high grade changes (high signal intensity on proton weighted MRI) compared with non-injured individuals.
True, this is evidence that the lesions are cause by the trauma.
Which ligaments in the upper cervical spine are often damaged in whiplash trauma and play an important role in chronic whiplash.
Alar strength
Most Alar ligament lesions as seen in Proton weighted MRI are near which insertion… the condylar insertion or the insertion at the dens?
Condylar insertion in 82 of 94 ligaments studied.
The central core of the alar ligaments is made up of what?
Collagen with a few elastic fibers peripherally.
Is collagen tolerant to elongation?
No, collagen can sustain 8% elongation. 200% elongation of elastic fibers.
A peripheral nerve can sustain 12% elongation before permanent damage.
A peripheral nerve can sustain 6% elongation and lose 70% of its action potential and recover 90+% in 1 hour «_space;muscle test this… stretch brachial plexus and test muscles.
Is it possible to have a substantial sideways shift of the atlas > than 1.5mm without damage to the alar ligaments?
Yes, according to the Krakenes paper in Neuroradiology 2002
Increased craniovertebral rotation following a whiplash injury suggests damage to what ligament?
Alar because they limit rotation
When viewed on Odontoid Digital Motion X-ray, how many mm of lateral translation of atlas on axis is considered unstable?
3mm
According to Goel, in Journal of Biomechanics 1988, the ligaments of the C0/1/2 level are considered lax, and the head is held firmly to the neck by what?
Muscles
What muscle originates on the spinous of T4-3-2-1-C7 and inserts on the superior nuchal line and posterior mastoid? What are its actions bilaterally and unilaterally?
Splenius capitus
Bilaterally extends the head
Unilaterally rotates the head ipsilaterally and lateral flexes the head
This muscle originates on the spinous process of T6-5-4-3 and inserts on the posterior transverse process of C2 and C3, and sometimes C1? What action when acting bilaterally? What action when acting unilaterally?
Splenius cervicis
Bilaterally extends the head
Unilaterally turns the head and laterally flexes
List the 4 suboccipital muscles
Rectus capitis posterior major and minor
Obliquus capitis superior and inferior
The greater occipital nerve is an extension of what?
Medial branch of dorsal ramus of C2 dorsal root (posterior primary ramus of C2)
It travels under the inferior oblique as it makes its way up the back of the head to the vertex of skull. It innervates the skin in the UC spine - back of head to vertex.
The lessor occipital nerve is an extension of what nerve?
Ventral ramus of C2 with a branch from C3
Travels posterior to the SCM
The greater occipital nerve pierces what muscle as it makes it way to the occiput?
Semispinalis capitus and upper traps
The suboccipital nerve (C1) exists where & innervates what group of muscles?
The suboccipital triangle
All suboccipital muscles. The rectus capitis lateralis is not a suboccipital muscle and is innervated by the anterior rami of C1.
What muscles make up the suboccipital triangle?
Obliquus capitis superior and inferior and rectus capitis posterior major
Who is considered the “father of spinal biomechanics”?
Giovanni Borelli 1608-1679
Who is considered the father of orthogonally based upper cervical care?
John Grostic
The AA articulation provides what degree of rotation to the left and right?
Approximately 40 degrees
How when that alars are taut at 10 degrees?
The AA articulation provides what percent of total rotation of the cervical spine?
50% - 60%
How many degrees of OA flex/extension (total)?
25 degrees (4 in flexion, 21 in extension)
The C0-C1 joint has very little motion in lateral flexion and rotation to each side… how much approximately?
0-5 degrees
During lateral flexion, the atlas translates slightly in what direction?
Ipsilateral translation of atlas
According to Ruth Jackson, the head and atlas move primarily as what on the axis in rotation and lateral bending movement?
One unit with a little side to side gliding movement (ipsilateral translation) due to the condyles of the skull
Penning (1978) stated that the movement, if possible at all, is so small.
T/F: There are various reports in the literature with some (White/Panjabi) stating that NO rotation occurs at the OA joint and others (Penning, Wilmink, Dvorak) reporting between 1-5 degrees to either side.
True
In the vertex position, does ROTATING the head 1⁄4, 1⁄2, or 1 inch in either direction change the rotation of the AO articulation?
No.
0-5 degrees of motion at the end of range.
In the vertex position, does TILTING the head 1⁄4, 1⁄2, or 1 inch from vertical, change the relationship between the condyles and atlas?
No.
0-5 degrees of motion at the end range
T/F: the movement at the AO joint occurs at the END RANGE OF MOTION.
True.
Does axial rotation of the sub-axial cervical spine accompany lateral bending in the same or opposite direction as axial rotation?
Same.
How many degrees of AO joint flexion/extension?
10 flex and 20 extension
How many degrees of AO lateral bending?
0-5 degrees
How many degrees of AO joint rotation?
0-5 degrees
How many degrees of AA rotation to each side?
39-47 degrees
How many degrees of AA lateral bending?
0-5 degrees
Normal cervical movement requires ________ motion.
Coupled
Coupled motion helps dissipate tension where?
In the joints and nervous system by offsetting purse lateral flexion or rotation with small movements in the x, y, and z axes.
When a joint misaligns in an uncoupled fashion we, as chiros, might call that?
Subluxation
Uncoupled misalignments are difficult to adapt to biomechanically and neurologically.
Spinal cord extends from the atlas to where?
L2-L3
The average length of the cord is?
40-45cm or 18 inches
What three membranes surround the cord?
Pia mater
Arachnoid mater
Dura mater
What is the space between the dura mater and the vertebral canal?
Epidural space (for veins)
The CSF is contained between which two layers?
Between the arachnoid mater and pia mater (aka subarachnoid space)
The pia mater adheres to what?
The spinal cord and its vascularity
T/F: The dentate ligaments strong enough to deform the cord.
True, they can scar both the white and grey matter.
T/F: Osseous misalignments are large enough to cause mechanical irritation to the spinal
cord.
True.
Attachments between the ligamentum nuchae and RCPMi and the dura occur between what vertebrae?
C0-C1 (RCPmi)
C1-C2 (Ligamentum nuchae)
Where is the Cranial durae matris spinalis ligament?
Fibrous strands between the dura and the posterior border of the AO-joint, the edge of the foramen magnum, the atlas posterior arch and the base of the spinous process and lamina of axis
T/F: The muscles that are associated with the cervical dural sleeve (suboccipital muscles) may work as a pump providing important force required to move CSF in the spinal canal.
True
T/F : The ligamentum nuchae contains a dense fibrous band that connects with the
dura mater at the C1/C2 level.
True
What is the name of the dense fibrous band connecting the ligamentum nuchae to the dura mater at the C1/C2 level?
“to be named ligament”
What is the ligament called that runs from the posterior aspect of the cervical dura mater to the posterior wall of the spinal canal at the C1/C2 level.
Vertebrodural ligament
T/F: The TBNL and VDL, firmly link the posterior aspect of the cervical dura mater to the posterior wall of the spinal canal and ligamentum nuchae.
True
T/F: The spinal dura is innervated and a source of pain.
True
A C0/C1/C2 subluxation can put tension on which ligaments?
Vertebrodural ligament
Cranial durae matris spinalis ligament
To Be Named Ligament
What happens to the spinal cord in flexion? What causes this?
Elongates and flattens. 30mm (approx. 1inch) change between extension to
flexion.
Dentate ligaments pull laterally, flattening the cord (Poisson’s effect)
What is Davis’ Law?
Soft tissue deforms according to imposed demands. Sustained kinks and twists cause ligamentous creep, and ultimately cervical
instability and accelerated spondylosis.
What is Wolff’s Law?
Hard tissue deforms according to imposed demands
Can cervical spondylosis cause loss of nerve cells and gliosis and degeneration of the grey and white matter?
Yes, the dentate ligaments at the level of spondylosis are usually thicker (due to sustained tension)
Ligamentous tensions can cause spinal cord lesions.
Traction on the spinal cord affects the nerve tracts by two means. Name them.
Direct mechanical irritation on the spinal cord.
Ischemia - closing veins of the cord producing stasis of blood in the cord with a loss of nutrients necessary to carry on the high energy reactions necessary for nerve conduction.
How much pressure is needed to induce venous congestion and functional impairment?
5-10mm Hg
What is the transverse diameter of the cord at C1?
12.5mm (0.5 in)
23mm diameter for the foramen
*T/F: A 3 degree C1 misalignment (3mm or 1/8 of an inch) could deform the cord by 25% of its diameter.
True
*Which ligaments were the most significant element in increasing tension requirements and SSEP alterations?
Dentate, short leg is on the side of dentate ligamental tension.
*T/F: 0.75 degrees is the minimum to put stress on the cord.
True, also the minimum to having a subluxation.
*Under normal conditions the maximum AP movement of the upper cervical spinal cord in the sagittal plan is about?
4mm, this causes shortening of the dentate ligaments.
*Grostic found the lateral deviation of the cord, due to shortening of the dentate ligaments to be what?
0.5mm, this is normal movement.
T/F: Traction on the cord by subluxations are smaller than those produced by normal movement.
False, traction on the cord by subluxations are LARGER than those produced by normal movement.
When a nerve is under 6% tension, it reduces the action potential by what amount within 1 hour?
70% reduction
Mild Leg length inequality has been associated with which 3 orthopedic disorders?
Stress fracture
Low back pain
Osteoarthritis
The trigeminocervical nucleus descends down to what cervical level?
C3-C4
Trigeminal nerve afferents and cervical C1-C2-C3 afferents converge where?
Trigeminocervical nucleus
T/F: Upper cervical subluxation has a negative effect on the glymphatic system
True
What does the glymphatic system do?
Delivers interstitial solutes and metabolic waste products from deep brain
tissues to the body’s lymphatic and venous circulation for clearance.
Conducts CSF though the deep brain tissue and removes cellular waste products, to the body’s venous circulation.
Provides immune surveillance
T/F: Its possible that disturbance in the glymphatic system and reduced jugular vein
outflow has a connection to the pathogenesis of MS.
True
The structure and movement of what anatomical structure may create impedance to intracranial fluid dynamics by occluding the jugular vein?
Upper cervical spine
Mandolesi has demonstrated a significant increased incidence of severe anterior intrusion of the internal jugular vein by what structure?
C1-C2
Mandolesi also showed reduction of jugular intrusion after a UC adjustment.
What structures exit the jugular foramen?
CN IX, X, XI, and the jugular vein
T/F: Subluxation of the upper cervical spine alters intracranial fluid dynamics and
can lead to neurodegenerative conditions.
True
T/F : UC corrections have been shown to be helpful in treating depression
True
T/ F : Spinal cord dimensions and volume in a living being is less than that of a cadaver.
True, see Choi and Abrahams Surgical Radiological Anatomy 1996 Study - Spinal cord dimensions increase with embalming
The Tucker study in the Journal of Bone and Joint Surgery concluded that at the extreme physiological axial rotation (approx. 47 degrees), the spinal canal was reduced by ____%
61% reduction
In the Tucker study in the Journal, it was determined that an atlanto-axial subluxation of up to _____mm would reduce the area of the spinal canal, in neutral position, to _____%.
9mm; 60%
T/F: The perception of every positive or negative physical phenomenon is governed by receptors of various types.
True
What are the three functional divisions of the nerve system?
Sensory
Integration
Motor
Which two receptor types play a vital role in all functional divisions of the nervous system?
Nociceptors and mechanoreceptors
How to mechanoreceptors activate?
Mechanical deformation
T/F: Skin, muscles, joints, and visceral organs all contain mechanoreceptors.
True
Mechanoreceptors covey _____ and _____ to the neuroaxis.
Tactile sensations; position sense
What are the 2 categories of position sense?
Static position
Kinesthesia
Define Static Position.
The conscious awareness of the orientation of different parts of the body with respect to each other.
Define kinestheisa.
The conscious awareness of body position and movement of muscles, tendons, joints
T/F : Mechanoreceptors make the brain aware of detailed information regarding the position and movement of each body part within a gravity environment.
True
What type of receptor provides information to the neuroaxis about the body’s relationship to the HORIZON?
Optic receptors
What informs the brain of the heads position, and works to keep it perpendicular with the ground by altering the tone of the cervical muscles?
Vestibular apparatus
It appears that small deviations of the skull, as little as ___ degrees, are detected by the membranous labyrinth.
0.5 degrees
T/F : The eyes play a more significant role in determining the position of the head in space when there is extreme head tilt.
True
Which two condition (in general) can result from a disturbance in the integration of afferent signals between the visual, vestibular, and proprioceptive (mechanoreceptor) systems?
Vertigo
Dizziness
Guyton states that the most important proprioceptive information required for the maintenance of equilibrium comes from?
Cervical joint receptors
In 1994 Spine Journal, McLain found that there were in fact mechanoreceptors in the cervical facet joints. And that the mechanical state of the capsule was under the constant surveillance of?
The central nervous system
T /F : Human supraspinal and intraspinal ligaments are not innervated.
False, according the Jiang, Spinal Journal 1995, they are well innervated.
This type of corpuscle is a slowly adapting end organ that is sensitive to static motion, especially to stretch and provides awareness of joint position and movement. They are very common in articulations where static position sense is necessary for the control of posture.
Ruffini corpuscles
T / F: Mechanoreceptors have been found in the outer 2-3 lamellae of the human IVD and ALL.
True, according to Roberts, Spine Journal 1995, these provided the individual with sensations of posture and movement.
Indahl, Kaigle, Reikeras Spine 1995 found that if the annulus fibrosis of the IVD was stimulated it caused reactions in the multifidus on multiple levels on which side? With stimulation of the facet joint capsule, which side were reactions on?
Stimulating the annulus reactivates the multifidi on the contralateral side at many segmental levels.
Stimulating the facet capsule reactivates the multifidi on the ipsilateral side on the same level.
According to Bogduk Spine 1999, the cervical annulus is thick ___(anteriorly or posteriorly)_____ and tapers laterally and is deficient _____(anterorlaterally or posterorlateraly)______.
Anteriorly; posteriolaterally
Bogduk described the architecture of the cervical annulus as a _______ _______ _____ ____ more than a ring of fibers surrounding the nucleus pulposis (like lumbar disc).
Crescentric anterior intervertebral ligament
At birth the cervical nucleus constitutes no more than ____% of the cervical disc.
25%
At birth the lumbar nucleus constitutes no more than ____% of the lumbar disc.
50%
T/F: Cervical herniated nucleus pulposus can be managed successfully with UC-care.
True
T /F: The thoracic and lumbar spine have more mechanoreceptors than the cervical spine.
False, according to McLain, Pickar study, Spine 1998
T/F: Mobility of a joint and number of mechanoreceptors are directly related.
True
The predominance of receptors in the cervical spine is consistent with its _____ mobility, the need to accurately position the _____ in space, and the need for coordinated muscle control for _____ and ______.
The predominance of receptors in the cervical spine is consistent with its GREATER mobility, the need to accurately position the HEAD in space, and the need for coordinated muscle control for PROTECTION and POSTURE.
There are 4 types of articular receptors, most of which are what type?
Type 1, Ruffini receptors, low threshold and slow to adapt. They signal the angle of joints through the ROM, stretch.
T/F: Type 1 Ruffini receptors are active at rest and with movement.
True
Type II receptors are ______ threshold and _____ adapt. When are they activated?
Type II receptors are LOW threshold and RAPIDLY adapt.
Type II, Pacinian, receptors are activated at the beginning and end of movement.
Type III receptors are _____ threshold, and ______ adapting. They are only activated at the ______ of joint movement. They are structurally similar to the ____ in the muscular system.
Type III receptors are HIGH threshold, and SLOWLY adapting. They are only activated at the EXTREMITIES of joint movement. They are structurally similar to the GOLGI TENDON ORGANS in the muscular system.
Type IV receptors are ______ threshold and _________ adapting.
Type IV receptors are HIGH threshold and NON-adapting.
What tract do Ruffini mechanorecptors transmit over?
Spinocerebellar tracts to the ipsilateral cerebellum.
What is the most numerous mechanoreceptors?
Type 1: Ruffini
What are the most active mechanoreceptors?
Type 1: Ruffini, active during static joint motion.
What tract do Pacinian mechanoreceptors transmit over?
Dorsal column-medial lemiscus to the contralateral thalamus
What type of mechanoreceptors is the golgi tendon organ?
Type III mechanoreceptor
This is the mechanoreceptor for pain.
Type IV - high threshold, non-adapting, normally inactive
According to Kulkarni-Chandy-Babu, Neurology India 2001, which suboccipital muscle has the greatest spindle density?
Obliquus capitus inferior, 242gm
T or F: Suboccipital muscles have GTOs.
False.
The high spindle density and lack of GTO’s indicates what about these muscles?
That they are not suited for movement, but for monitoring craniovertebral position and movement and sending afferent input into the neuroaxis.
Suboccipital muscles MONITOR but don’t MOVE the CCJ.
GTO sense muscle tension from contraction… when contraction is too much the GTO activates and inhibits further contraction. Pressing Tendons/GTO’s toward
the O/I inhibits the muscle reflexively.
T /F: Muscles involved in delicate Vernier movements may require a signal that has a finer resolution than muscles subserving coarser movements, and such high resolution will require many spindles.
True, according to Bakker and Richmond study.
Where does virtually all sensory information from somatic segments of the body enter the spinal cord?
Dorsal spinal nerve roots
What are the 4 main pathways sensory information is conveyed up into the neuroaxis?
- Dorsal column-lemniscal system (fasciculus gracilis and cuneatus)
- Spinocervical tract
- Spinocerebellar tract (dorsal and ventral - cuneocerebellar and rostral spinocerebellar)
- Anteriolateral (spinothalamic & spinoreticular)
Mechanoreception enters the dorsal root & synapses with what part of the cord?
Dorsal white columns
Each proprioceptive fiber divides to form how many branches?
2, the medial and the lateral
The medial branch turns upwards into what two pathways?
Fasciculus Gracilis & Faciculus Cutneatus
T or F: The lateral branch proceeds laterally and anteriorly and divides many times and gives off one terminal to the spinal cord and gray matter.
False, it gives off MULTIPLE terminals.
Some of the lateral branch terminals elicit local spinal cord reflexes, while others excite relay neurons that give rise to the _______ and ______ tracts.
Spinocerebellar (ipsilateral); spinocervical
DCLS carries _________ mechanoreceptive signals to the ______of the medulla.
DCLS carries IPSILATERAL mechanoreceptive signals to the NUCLEUS GRACILIS & NUCLEUS CUNEATUS of the medulla.
At the level of the nucleus gracilis and nucleus cuneatus in the medulla, second order neurons cross over to the opposite side and travel to the _______ by way of the medial lemniscus.
At the level of the nucleus gracilis and nucleus cuneatus in the medulla, second order neurons cross over to the opposite side and travel to the THALAMUS by way of the medial lemniscus.
The most medially placed fibers in the fasciculus gracilus arise from where?
The coccygeal dorsal roots
The most laterally placed fibers in the fasciculus gracilus arise from where?
The mid thoracic segments
The most medially placed fibers in the faciculus cuneatus arise from where?
The mid thoracic segments
The most laterally placed fibers in the faciculus cunetus arise from where?
From the C2 dorsal roots
Which tract is more medial in the cord? Fasciculus gracilus or cunetus?
Gracilus
The spinocervical tract functions in close association with what system?
DCLS: transmits signals from rapidly adapting receptors Pacinian and Meissner corpuscles
Spinocervical tract is considered an accessory tract
Pacinian and Meissner corpuscles are low threshold and rapidly adapting receptors that convey what types of sensation?
DCML: Fine touch, 2-point discrimination, pressure, vibration, stereognosis and some proprioception related to body position.
Which two tracts transmit low threshold slow adapting position sense signals?
Spinocervical and spinocerebellar
Which two tracks play an important role in the coordination of locomotion and position sense transmission from the periphery to the cerebellum.
Spinocerebellar tract
Cuneocerebellar tract
The dorsal spinocerebellar tract (DSCT) originates where?
Sacral, lumbar and thoracic segments of Clarks nucleus in the gray matter from C8-L3
Describe the pathway of the dorsal spinocerebellar tract?
Neuro muscular spindle –> dorsal root ganglion –> dorsal white matter –> Clark’s nucleus –> spinocerebellar tract –> cerebellum
Secondary afferent fibers from Nucleus dorsalis of Clarke enter the dorsal spinocerebelar tract and ascend ________ up to the brainstem.
Secondary afferent fibers from Nucleus dorsalis of Clarke enter the dorsal spinocerebelar tract and ascend IPSILATERALLY up to the brainstem.
The spinocerebellar fibers are organized such that the most caudal fibers lie _________ & the most rostral fibers lie _________ in the tract.
The spinocerebellar fibers are organized such that the most caudal fibers lie LATERAL & the most rostral fibers lie MEDIAL in the tract.
The DSCT terminates where?
Ipsilateral cerebellum
What is the DSCT transmitting?
Unconscious proprioception from muscle spindles and other mechanoreceptors (GTO)
The afferent input from the DSCT informs the cerebellum of the instantenous status of what 4 things?
Muscle contraction and length (via muscle spindles)
Tension on the muscle tendons (golgi tendon organs)
Positions and rate of movement for joints and body parts
Forces on the surface of the body
T/F: The cerebellum can compare afferent input and efferent output from higher motor centers in order to influence movement and performance.
True
Which tract enters the cerebellum through the superior cerebellar peduncle and terminates on BOTH sides of the cerebellum?
Ventral spinocerebellar tract.
Where does the spinocerebellar tract enter and terminate in the skull?
Enters through the inferior cerebellar peduncle and terminates in the cerebellum ipsilaterally
T/F: the VSCT has only crossed fibers?
False, the ventral spinocerebellar tract has crossed AND uncrossed.
T/F: Many of the decussating fibers of the VSCT cross again as they reach the cerebellum.
True
What primarily excites the VSCT?
Motor signals from the corticospinal and rubrospinal(upper extremity flexors) tracts that appraise the cerebellum that the motor signals have arrived at the cord, and the intensity of the signals as well.
This is how the cerebellum can compare afferent input and motor out from higher (cortical) brain centers.
Which pathways have the most rapid conduction velocity in the entire neuroaxis?
Spinocerebellar tracts at 100meters/second.
This speed is necessary for the cerebellum to have instantenous information of the
changes that take place in the body.
Which two tracts relay proprioceptive information from the cervical dorsal roots?
Cuneocerebellar and rostral spinocerebellar tract.
The VSCT and DSCT range from C8-L3.
The cuneocerebellar and rostral spinocerebellar tracts transmit ________ to the cerebellum.
The cuneocerebellar and rostral spinocerebellar tracts transmit IPSILATERALLY to the cerebellum.
Ipsilaterally via the fasciculus cuneatus>caudal medulla>accessory cuneate nucleus
Rostral spinocerebellar tract runs roughly with the VSCT
The cerebellum constitutes what % of the brain?
10%
What part of the neuroaxis has the most neurons?
The cerebellum
This is due in part to the fact that we live in a gravity environment.
It has been suggested that afferent input to the cerebellum exceeds efferent by a ratio of?
40 to 1
Afferent > Efferent
Sensory input more important for proper nerve system
T/F : All sensory afferent information is summated in the thalamus.
False, all but olfactory
T/F: All sensory afferent information is integrated in the thalamus.
False, all but olfactory
The vertebral artery supplies blood to every cranial nerve except for which nerve?
CN 1 (Olfactory)
Cortical firing is dependent on what?
Thalamic summation and integration
What are the two types of thalamic summation?
Spatial and temporal
Describe spatial summation
Increasing the INTENSITY of transmission into the neuroaxis by
USING MORE NERVE FIBERS. Increasing SPACE for more nerve fibers.
Describe temporal summation.
Increase in the STRENGTH of transmission into the neuroaxis by sending MORE IMPULSES PER FIBER. Tempo-drumming-one hand-one fiber- with more TEMPO
What is Thalamic integration?
The routing of afferent input to the appropriate region of the cerebral cortex.
T/F: The sensory signals are filtered along the synaptic relay stations so that the incoming cortical messages have been previously fine-tuned.
True
This helps prevent an efferent impulse response from each and every afferent input. The brain discards >99% of all incoming sensory information as being irrelevant and unimportant.
What does the Thalamic Neuron Theory postulate?
That the CNS is involved in all disease processes.
As it handles all incoming and outgoing signals in order to maintain homoeostatis.
Lee, Theoretical basis for the role played by the CNS in the causes and cures of
all diseases: Medical Hypothesis 1994
T/F : Stretching a single lateral ligament of the spine can produce a barrage of sensory feedback from several spinal cord levels on both sides of the spinal cord.
True
This information is transferred via the dorsal columns and spinocerebellar tracts to higher levels in the brain including the nucleus gracilis, nucleus cuneatus, vestibular nuclei and thalamus. (Spine 1997 Jiang)
T/F: Proprioceptive neck afferents have no effect on the control of posture, head position, or eye movements.
False, they do via rostral (rostral spinocerebellar) cervical afferents synapse with pre-cerebellar, vestibulospinal, and preoculo-motor neurons.
T/F: A small percentage (8%) of the neck responsive neurons in the medulla were shown to project rostrally to the thalamus.
True, according to Bolton, Brain Research 1992
Muscle afferent input may converge with the cardiorespiratory receptor input and facilitate the release of Substance P in the Nucleus tractus solitarii (NTS). What does substance P do?
Substance P is involved in mediating central autonomic neurotransmission and nociceptive and non-nociceptive stimuli in the spinal pathways.
The NTS (nucleus tractus solitarii) collects and transmits what type of afferent input
Viscerosensory
It’s a vagal nerve nuclei
Viscerosensory input to the NTS affects visceral output through the …
Dorsal motor nucleus of vagus (DMNV)
T/F : Visceral motor output has been shown to affect the immune system and host resistance.
So muscle afferent input affects immune system and host resistance.
T/F : Spinal subluxation can affect the firing of paraspinal muscles, which distorts afferentiation into the neuroaxis. The adjustment improve afferentation to the neuroaxis and may improve function of the NTS and resultant DMNV visceral output.
True
T/F: Sensory information from the upper neck is important in the reflex control of posture and eye position.
True
T/F: Sensory information from the upper neck is not linked to autonomic control of the cardiovascular or respiratory systems.
False, it is linked to these systems.
T/F: Whiplash and cervical dystonia, due to the disturbance in afferentation in the cervical spine can cause oromotor, respiratory and cardiovascular abnormalities.
True
What neural pathways are involved in this process?
Intermedius nucleus of the medulla (InM) receives afferent information from the
upper cervical spine and links to the respiratory, cardiovascular, postural, oro-
facial, hypoglossal nucleus, fascial and motor trigeminal nuclei, parabrachial
nuclei, rostral and caudal ventrolateral medulla and nucleus ambiguous (heart)
The InM integrates information from the ____ and ___ and relays this information to the NTS where autonomic responses can be generated via the DMNV. It also projects to the hypoglossal nucleus to influence movements of the tongue and upper airway.
The InM integrates information from the HEAD and NECK and relays this information to the NTS where autonomic responses can be generated via the DMNV. It also projects to the hypoglossal nucleus to influence movements of the tongue and upper airway.
T or F: Sensory afferent signals from the neck can influence central cardiorespiratory control as components of postural reflexes via the InM.
True
As the InM receives afferents from the neck muscles spindles and sends both excitatory and inhibitory signals to the NTS which then influences cardiorespiratory centers.
