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