MEMORISE FOR FINAL Flashcards
name the tarsal bones
talus, calcaneus, navicular, medial cuneiform, intermediate cuneiform, lateral cuneiform and cuboid
foot arches and the bones that comprise these arches
Medial Longitudinal Arch: - 1st, 2nd, 3rd ray - cuboid - calcaneus Lateral Longitudinal Arch: - 5th ray - calcaneus Transverse Arch: - 1st to 5th MT
How does the structure of a lumbar intervertebral disc aid its role in WEIGHT-BEARING?
- nucleus pulposus in incompressible
- vertical compression of nucleus pulposus (decrease vertical height)
- expands radially and exerts pressure on annular fibres
- annular fibres contain collagen which resists tension
- annular fibres exert pressure back on nucleus pulposus
- nucleus pulposus and annular fibres share the load
- pressure exerted onto vertebral endplates
- transmits load to inferior vertebrae
How does the structure of a lumbar intervertebral disc aid its role in FACILITATING MOVEMENT?
- the intervertebral disc interposed between two flat articular surfaces permits rocking of superior vertebrae and allows the compromise of movement and stability
- deformation of the intervertebral disc contributes to intervertebral motion
- high intervertebral disc height to vertebral body height ratio allows high mobility
How does the structure of a lumbar intervertebral disc aid its role in RESISTING MOVEMENT?
- collagen fibres in annulus fibrosus resist tension
- in F, E, and LF the compression of intervertebral discs leads to restriction of these movements
How does the intervertebral disc height to vertebral body height ratio effect the movement available at a motion segment?
- if ratio is low = lower mobility/greater stability
- increased separation between vertebral bodies= increased motion
How does the height of the superior articular process effect the movement available at a motion segment?
- flexion is limited as the inferior articular process cannot lift over the superior articular process
How does the zygapophyseal joint orientation in the different spinal levels effect the movement available at a motion segment?
Cervical:
- transverse plane = allows all movements
Thoracic:
- coronal plane
= resists anterior translation and F/E
= allows axial rotation and LF
Lumbar:
- sagittal plane
= resists axial rotation
= allows F/E and LF
How do the ligaments effect the movement available at a motion segment?
- when a ligament tightens they resist excessive movement
Name the innervated structures of the Sympathetic Trunk and Grey Rami Communicantes and the nerve structure it arises from
Nerve structure= anterior vertebral plexus Innervated structures: - anterior outer annulus fibrosus - anterior longitudinal ligament - anterior vertebral periosteum - vertebrae and blood vessels
Name the innervated structures of the Sinuvertebral Nerve off Ventral Rami and the nerve structure it arises from
Nerve structure= posterior vertebral plexus
Innervated structures:
- posterior outer annulus fibrosus
- posterior longitudinal ligament
- posterior vertebral periosteum
- anterior and ventral/lateral dura and nerve root sleeves
- vertebrae and blood vessels
Name the innervated structures of the Dorsal Rami and the nerve structure it arises from
Nerve Structure= medial branch
Innervated structures:
- zygapophyseal joint above and below
- muscles: interspinales, rotatores, multifidus and semispinalis
Nerve Structure= intermediate branch
Innervated structures:
- longissimus
Nerve Structure= lateral branch
Innervated structures:
- erector spinae
How does the structure of Longissimus pars thoracis and iliocostalis lumborum pars thoracis relate to their function
> Prime extensors of the thoracolumbar spine
- vertical line of action
- large PCSA
- large posterior moment arm
- crosses many segments
Unilateral action: LF (iliocostalis lumborum is better)
Bilateral action: E
iliocostalis pars thoracis also derotates
How does the structure of longissimus thoracis pars lumborum and iliocostalis lumborum pars lumborum relate to their function
> Unilateral action:
-vertical line of action lateral to axis=LF
Bilateral action:
-vertical line of action posterior to axis=E
-horizontal line of action=posterior shear
Other notes:
- deeper than pars thoracis
- attaches to lumbar transverse processes superiorly
How does the structure of Multifidus relate to its function
> Lateral view:
- vertical line of action posterior to axis= E and maintains lumbar lordosis
- no translation results from contraction
Posterior view:
- small horizontal component which could assist with rotation
- abdominals produce F and R: multifidus cancels out F with E
What are the functions of the Thoracolumbar Fascia
- to provide stability to the spine when tensed (caused by muscles contracting and bulging)
How can increasing intra-abdominal pressure contribute to stability of the lumbar spine?
- increased IAP= more stability and support for the trunk
- results in increased extensor moment and increased force required to flex the spine
- when IAP increases the cavity will want to expand to compensate (prevented by muscles) - muscles have to contract in order to increase IAP
- when IAP increases, it creates force surrounding the vertebral column, causing it to stiffen
How does abdominal muscle co-contraction contribute to stability of the lumbar spine?
- one muscle contracting bilaterally or a muscle and its antagonist contracting simultaneously
- compresses the lumbar spine, resulting in stability
How does Thoracolumbar Fascia (abdominopelvic muscle attachments) contribute to stability of the lumbar spine?
- when certain muscles contract and swell, the surrounding fascia tenses, increasing stability by resisting flexion or producing extensor moment
e. g. - when the Quadratus lumborum contracts, the middle and anterior thoracolumbar fascia tenses
- thoracolumbar fascia connects to points on the vertebral column (transverse and spinous process). Therefore, when the thoracolumbar fascia tenses, it pulls the vertebral column inferiorly, compressing and stabilising it
Complete the Following pathways/tracts
- anterolateral
- dorsal column
- post spinocerebellar
- cuneocerebellar
- ant spinocerebellar
- lateral corticospinal
- anterior corticalspinal
- corticonuclear
- reticulospinal
- rubrospinal
- vestibulospinal
- tectospinal
- direct pathway (with and without SNc influence)
- indirect pathway (with and without SNc influence)
see booklet for answers
Draw the visual pathway and discuss lesions to the pathway
see booklet for answers
Describe the processes of the following reflexes
- corneal blink reflex
- pupillary light reflex
- vestibule-ocular reflex
- accomodation reflex
see booklet for answers
Discuss the cerebrocerebellar loop with regards to:
- structures involved
- connectivity
- function
- Structures involved
- lat hemispheres of cerebellum
- dentate nucleus - Connectivity
- afferent fibres = contralateral premotor cortex
- efferent fibres= motor cortex via thalamus and red nucleus - Function
- coordinate fast and alternating movements
Discuss the spinocerebellum loop with regards to:
- structures involved
- connectivity
- function
- Structures involved:
- ant lobe, vermis, intermediate hemispheres
- fastigial and interposed nuclei - Connectivity:
- spinal cord: post spinocerebellar and cuneocerebellar - Function:
- regulates muscle tone, posture and balance
Discuss the Vestibulocerebellar loop with regards to:
- structures involved
- connectivity
- function
- Structures involved:
- flocculonodular lobe
- fastigal nucleus - Connectivity:
- vestibular nuclei and nerve - Function
- corrects the three vestibulo reflexes
Discuss an UMN Lesion above the midbrain
= results in removal of influence of corticospinal tracts (known as decortication) on the rubrospinal, reticulospinal and vestibulospinal tracts
symptoms:
- decorticate rigidity with flexion of UL and extension of LL
Discuss an UMN Lesion below the midbrain
= results in the removal of the rubrospinal tract in addition to the removal of the influence of the corticospinal tracts on the reticulospinal and vestibulospinal tracts
symptoms:
- decerebrate rigidity with extension of both UL and LL due to unopposed extensor biased UMN activity
Huntington’s disease is characterised by selective degeneration of the striatum. Answer the following:
a. Which neuronal receptors are mainly effected?
b. Which pathway does it affect?
c. What pathological observation can be seen in the brain of a person with HD?
d. Describe the symptoms of HD
a. selective degeneration of D2- receptor neurons
b. reduced activity of indirect pathway
c. lesion in striatum (caudate nucleus)
d.
- excessive involuntary movement
- chorea
With regards to Parkinson’s disease Answer the following:
a. Which neuronal receptors are mainly effected?
b. Which pathway does it affect?
c. What pathological observation can be seen in the brain of a person with PD?
d. Describe the symptoms of PD
a. degeneration of SNc
b. reduced activity of direct pathway
c. substantia nigra becomes less visible (lighter)
d.
- reduced voluntary movements
- increased involuntary tremors
Name 4 muscles that contribute to dorsiflexion of ankle
- tibialis anterior
- extensor digitorum longus
- extensor hallucis longus
- fibularis tertius
Name 4 muscles that contribute to plantar flexion of ankle
- gastrocnemius
- soleus
- flexor hallucis longus
- tibialis posterior
Name 4 muscles that contribute to inversion of ankle
- tibialis anterior
- tibialis posterior
- gastrocnemius
- soleus
Name 4 muscles that contribute to eversion of ankle
- fibularis longus
- fibularis brevis
- fibularis tertius
- extensor digitorum longus
Name 2 flexors of the toes
- flexor digitorum longus
- flexor hallucis longus
Name 2 extensors of the toes
- extensor digitorum longus
- extensor hallucis longus
Name the bilateral and unilateral actions of Upper Trapezius
B= extension U= ipsilateral LF, axial rotation
Name the bilateral and unilateral actions of Levator Scapulae
B= extension U= ipsilateral LF, axial rotation
Name the bilateral and unilateral actions of Sternocleidomastoid
B= upper cervical extension, lower cervical flexion U= ipsilateral LF, axial rotation
Name the bilateral and unilateral actions of Scalenes
B= flexion U= ipsilateral LF
Which intrinsic back muscles contribute to EXTENSION
- longissimus thoracis pars thoracis
- iliocostalis lumborum parts thoracis
Which intrinsic back muscles contribute to FLEXION
- iliocostalis lumborum parts thoracis
Which trunk muscles contribute to ROTATION
- external and internal obliques
- multifidus
Which trunk muscles contribute to LATERAL FLEXION
- all abdominal muscles
Actions of Psoas Major
- hip flexor
- lumbar spine compressor
Actions of Quadratus Lumborum
- ipsilateral LF
Name the bilateral and unilateral actions of External Oblique
B= flexion and IAP U= axial rotation and ipsilateral LF
Name the bilateral and unilateral actions of Internal Oblique
B= flexion and IAP U= axial rotation and ipsilateral LF
Name the actions of Transverse Abdominis
- increased IAP
Name the actions of Rectus Abdominis
- flexion
Describe the visual pathway process
- begins in the eye- photoreceptors (rod and cones) in the retina
- photoreceptors stimulate 1st order neurons (bipolar cells)
- bipolar cells synapse with ganglion cell
- axons of ganglionic cell exit eye through optic disc as optic nerve
- optic nerve crosses optic chiasm and becomes optic tract
- optic tract synapses at LGN
- 3rd order neurons travel to primary visual cortex
A muscle’s action can chance in different joint positions. How does this statement apply to gluteus medius?
In 0 degrees flexion:
- anterior compartment = medial moment arm
- middle and posterior compartment = lateral moment arm
As hip flexors:
- anterior compartment = medial moment arm
- middle and posterior compartment = medial moment arm
Why is the molecular layer of the cortex exceptionally thicker than the white matter?
= because the cerebellum does not have commissural or association fibres; therefore, not a lot of white matter is needed
= thus, the molecular layer is there to connect the cortex and the cerebellar nuclei
Where do climbing fibres travel? and where are they from
= to Purkinje cells
- only from the inferior olivary nucleus
Where do mossy fibres travel? and where are they from
= to granular cells
- from everywhere
How does the diaphragm contribute to postural stability?
- contraction pulls the central tendon inferiorly, thus increasing insert-abdominal pressure
- intra-abdominal pressure: creates increased stiffness and creates an extensor moment
How does the respiratory drive affect the postural activity of the diaphragm
= when respiratory drive is increased, the diaphragm return to only respiratory functions, because this is more important than postural stability
How does the activity of the pelvic floor muscles relate to trunk/spinal stability
- the pelvic floor resists inferior protrusion when intra-abdominal pressure increases
- intra-abdominal pressure stabilises the vertebral column by creating a force around the vertebral column
Describe the anterior and middle layers of the Thoracolumbar Fascia
- thin and flimsy
- anterior layer is anterior to quadratus lumborum
- middle layer is posterior quadratus lumborum
- anterior and middle layers fuse at lateral margin of quadratus lumborum
- fusion is the site of attachment for transverse abdominis and internal oblique
- attaches to lumbar transverse processes
Describe the posterior layer of the Thoracomulbar Fascia
- thick and defined: particularly in lumbar region
- wraps around erector spinae
- provides site of attachment for gluteus maximus and latissimus dorsi
- blends with erector spinae aponeurosis
- attaches to spinous process
Is the Thoracolumbar Fascia different to the erector spinae fascia
- YES
- they blend together but are different structures
- erector spinae aponeurosis= caudal tendon of LT and IL pars thoracis
How does Increasing Intra-abdominal pressure lead to stability of the abdominopelvic cavity and lumbar spine
- increased IAP= more stability and support for the trunk
- results in increased extensor moment and increased force required to flex the spine
- when IAP increases the cavity will want to expand to compensate (prevented by muscles) - muscles have to contract in order to increase IAP
- when IAP increases, it created force surrounding the vertebral column, causing it to stiffen
How does abdominal muscle co-contractioin lead to stability of the abdominopelvic cavity and lumbar spine
- one muscle, contracting bilaterally or a muscle and its antagonist contracting simultaneously
- compresses the lumbar spine, resulting in stability
How does the Thoracolumbar Fascia (and abdominopelvic muscle attachments) lead to stability of the abdominopelvic cavity and lumbar spine
- when certain muscles contract and swell, the surrounding fascia tenses, increasing stability by resisting Flexion or producing extension moment
e.g.
when the quadratus lumborum contracts and the middle and anterior TLF tenses
therefore,
the TFL connects to points on the vertebral column (transverse or spinous process)
therefore,
when the TFL tenses it pulls the vertebral column inferiorly; compressing and stabilising it
How does the vertebral body resist compression?
inner portion is cancellous bone, the vertical trabecular, supported by horizontal trabeclue, which both withstand compressive forces
How do the articular processes and zygapophyseal joints resist compression
- some compression force is transmitted from inferior articular process of superior vertebra to the superior articular process or pars interarticularis of the vertebrae below
how do the superior vertebra resist anterior translation on the inferior vertebra
= due to the alignment of vertical spinous processes in the coronal plane
How does the interspinous ligament resist posterior translation of the superior vertebra on the inferior vertebra
= interspinous ligament runs anteriorly-inferiorly from the superior spinous process; thus resisting posterior translation of superior vertebra
How do the intervertebral discs resist posterior translation of the superior vertebrae on the inferior vertebra
= the alternate fibres of consecutive concentric annulus fibrosus rings means that 50% of the fibres (ruling ant-in) resist each other
How does the internal vertebra resist torsion
- AF aligned at 45 degrees and therefore, 50% tighten in one direction
- also due to arrangement of trabecular; thick pedicles attach posterior elements to vertebral body
How does axial rotation of sup. vertebra on inf. vertebra resist torsion
- subsequent concentric layers of the AF, superior facets are aligned in sagittal plane, impact of articular processes provides physical resistance to axial rotation
- L- shaped zygapophyseal joints also resist
What 8 things resist FLEXION in the vertebral column
- tall superior articular processes blocking anterior translation on the superior (e.g. in thoracic)
- zygapophyseal joints aligned in coronal plane (e.g. thoracic)
- compression in anterior intervertebral disc
- tension in the posterior AF
- tension in PLL, ligamentum flavuum, supraspinatus ligament and ligamentum nuchae
- tension in zygapophyseal joint capsules
- tension in posterior muscles and fascia
- ribs
What 5 things resist EXTENSION in the vertebral column
- zygapophyseal joints aligned in coronal plane (thoracic)
- compression in posterior intervertebral disc
- tension in anterior AF fibres
- tension in ALL
- tension in anterior muscles
What 5 things resist LATERAL FLEXION in the vertebral column
- compression of ipsilateral lateral intervertebral disc
- tension of contralateral lateral AF fibres
- tension of contralateral ligaments (intertransverse ligaments)
- tension of contralateral zygapophyseal joints
- tension of contralateral muscles
What 3 things resist ROTATION in the vertebral column
- high superior articular processes block anterior rotation
- zygapophyseal joints aligned in sagittal plane (i.e. in lumbar region)
- 50 % of fibres in AF resisting/tensing
Describe movement in the mid/lower cervical spine
- zygapophyseal joints aligned in almost transverse plane, allowing all movements
Describe movement in the mid thoracic spine
- zygapophyseal joints aligned in coronal plane; allowing axial rotation and ipsilateral lateral flexion and resisting anterior translation and F/E
- tall superior articular processes resisting flexion in this region
- long, inferiorly facing spinous processes resist extension
- small, intervertebral disc height, limiting movement
Describe movement in the mid lumbar spine
- zygapophyseal joints aligned in the sagittal plane; allowing F/E and LF while resisting axial rotaiton
- large intervertebral disc height allowing movement
Portions of a large muscle may have different actions. How does this apply to gluteus maximus?
superior part= abduction
inferior part= adduction
both parts= hip extensors
What is the extensor hood mechanism?
= is the special connective attachments by which the extensor tendons insert into the phalanges
- function= muscles of extensor hood mechanism contract against the force of the long finger flexors putting a brake on the action of the FDS and FDP
- without the extensor hood mechanism, the fingers would be pulled into a total flexion pattern by the external flexor muscles
