Neurological Diseases - Spinal Disorders Flashcards
what makes up the vertebral column?
Cervical spine
Thoracic spine
Lumbar spine
Sacrum and Coccyx
what are the three regions of the cervical spine?
Atlanto-axial joint (C1–C2)
Subaxial spine (C3–C6)
Transitional vertebra C7
how would you describe the features of C1 (atlas)?
Ring-shaped
consists of an anterior (shorter) and posterior (longer) arch that fuses laterally to the lateral masses.
Has no body or spinous process but has large transverse processes that serve as attachments for superior and inferior oblique muscles.
The transverse processes are penetrated by the foramen transversarium accommodating the vertebral artery on either side.
what is C1 known as?
atlas
what is C2 known as?
axis
what is the main feature of the C2 (atlas)?
Has body and a distinct 15mm (range 9–21mm) high odontoid process (dens) that projects anteriorly at an average angle of 13°.
how would you describe C3-C6 vertebrae?
The vertebral bodies are small, concave on the superior surface, and convex on the inferior surface and have AP diameter smaller than the lateral diameter.
The spinal canal has a triangular shape and a sagittal diameter at C3–C6 of ~18mm.
what is C7 known as?
prominens
what does C7 mark?
cervicothoracic junction.
The sagittal diameter of the spinal canal is 15mm, the smallest in the cervical spine.
what are features that apply to all cervical vertebrae?
The uncinate (‘hook-like’) processes: are bony prominences of the superolateral aspects of the C3–C7 vertebral bodies which restrict lateral flexion.
The uncovertebral joint : between the uncinate process and the superior vertebra. The distance between the tip of the uncinate process and the laterally placed vulnerable VA is ~ 1mm (range 0–3mm).
The spinous processes: bifid and project inferiorly. The large spinous process of C7 is not bifid and serves as a surgical landmark
what are The uncinate (‘hook-like’) processes of cervical vertebrae?
bony prominences of the superolateral aspects of the C3–C7 vertebral bodies which restrict lateral flexion.
what is the uncovertebral joint of cervical vetebrae?
between the uncinate process and the superior vertebra. The distance between the tip of the uncinate process and the laterally placed vulnerable VA is ~ 1mm (range 0–3mm).
how would you describe the thoracic spine?
Heart-shaped body
Small circular spinal canal which provides the least spacious accommodation for the spinal cord.
The height and width of the thoracic pedicles increase in a superior to inferior direction.
The ribs articulate with the thoracic vertebrae in the body (costovertebral joint) and in the transverse process (costo-transverse joints).
Rib attachments render the thoracic spine biomechanically stiffer.
how would you describe the body of the lumbar spine?
massive kidney-shaped bodies, transmitting the body’s weight to the sacrum, and also have sturdy laminae and no costal facets.
Similar to the thoracic spine, the widths of the lumbar pedicles increase from L1 to L5.
what three zones is the sacrum divided into?
Lateral zone crossed medially to laterally by the sympathetic trunk, lumbosacral trunk, and obturator nerve
Intermediate zone which includes the sacral foramina
Medial zone which includes the sacral vertebrae
how do the sacral verebrae fuse?
The sacral vertebrae fuse and become progressively smaller forming the triangular sacrum that effectively transmits the body weight to the pelvis.
what are the spinal ligaments?
anterior and posterior atlanto-occipital membrane
transverse ligament
cruciate ligament
apical ligament
alar ligaments
anterior longitudinal ligament
posterior longitudinal ligament
ligamentum flavum
supraspinous ligament
what is the anterior and posterior atlanto-occipital membrane?
stretched from the anterior and posterior arches of C1 to the corresponding parts of the foramen magnum.
what is the transverse ligament?
transverse ligament is a strong ligament: grooves and holds the dens in position.
what does rupture of the transverse ligament result in?
Rupture or inflammatory degeneration of the transverse ligament results in atlanto-axial dislocation.
what is the cruciate ligament?
formed by two weaker ligamentous bands that run form the dens, superiorly to the basiocciput, and inferiorly to the body of C2.
what is the apical ligament?
runs from the tip of the dens to the anterior part of the FM
what is the anterior longitudinal ligament?
on the anterior surfaces of the vertebral bodies as the continuation of the anterior atlanto-occipital membrane and ends at the upper sacrum.
what is the posterior longitudinal ligament?
on the posterior surface of the vertebral bodies as a continuation of the tectorial membrane.
what is the ligamentum flavum?
composed of yellow elastic fibres which are perpendicularly oriented, and extends from facet joints to the base of spinous processes (from C2–C3 to L5–S1).
what is the supraspinous ligament?
connects the tips of the spinous processes and extends from C7 to the sacrum.
what is the atlanto-occipital joint?
This joint allows flexion, extension (the nodding ‘yes’ joint) and some lateral flexion.
what are the atlanto-axial joints?
A median pivot joint: anterior part of the dens articulates with the back of anterior arch of C1.
A lateral gliding joint: inferior facet of C1 articulates with the superior facet of C2). These joints allow mainly rotation (the shaking ‘no’ joint) as the skull and C1 rotate on C2 as a unit.
what is a median pivot joint?
anterior part of the dens articulates with the back of anterior arch of C1
what is a lateral gliding joint?
inferior facet of C1 articulates with the superior facet of C2). These joints allow mainly rotation (the shaking ‘no’ joint) as the skull and C1 rotate on C2 as a unit.
where are the intervertebral discs located?
C2–3 to L5–S1
which intervertebral discs are the thinnest?
thoracic discs are the thinnest
lumbar discs are the thickest, and have greater height anteriorly to maintain the lordotic curve.
what is the nucleus pulposus?
centrally and posteriorly placed, avascular and receives its nutrients from the vertebral body and the periphery of the annulus
what is the annulus fibrosus?
peripherally placed, composed of oblique layers of lamellae and is strongly attached to the vertebral end-plates.
what are the end plates?
allows diffusion of nutrients from the bone to the disc.
what does spinal stability depend on?
at least two intact columns
what are the three different columns of three-column theory?
anterior: anterior longitudinal ligament, anterior half of annulus fibrosus, and vertebral body.
Middle: posterior longitudinal ligament, posterior half annulus fibrosus, and vertebral body.
Posterior: Osseous and ligamentous structures posterior to the posterior longitudinal ligament (interspinous ligaments).
describe the anterior column?
anterior longitudinal ligament, anterior half of annulus fibrosus, and vertebral body.
describe the middle column?
posterior longitudinal ligament, posterior half annulus fibrosus, and vertebral body.
describe the posterior column?
Osseous and ligamentous structures posterior to the posterior longitudinal ligament (interspinous ligaments).
how many pairs of spinal nerves are there?
31 pairs of spinal nerves
list the different types of spinal nerves?
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
what is located at C2?
occipital protuberance
what is located at C3?
supraclavicular fossa
what is located at C4?
top of acromioclavicular joint
what is located at C5?
lateral side of antecubital fossa
what is located at C6?
thumb, dorsal surface, proximal phalanx
what is located at C7?
middle finger, dorsal surface, proximal phalanx
what is located at C8?
little finger, dorsal surface, proximal phalanx
what is located at T4?
nipple line
what is located at T10?
umbilicus
which dermatomes are responsible for the biceps reflex?
(C5-C6)
which dermatomes are responsible for the siponator reflex?
(C6-C7)
which dermatomes are responsible for the triceps reflex?
(C7-C8)
which dermatomes are responsible for the abdominal reflex?
(T8-T9/T10-12)
which dermatomes are responsible for the creamasteric reflex?
(L2-L3)
which dermatomes are responsible for the knee jerk reflex?
(L3-L4)
which dermatomes are responsible for the ankle jerk?
(S1-S2)
which dermatomes are responsible for the Anal cutaneous reflex?
(S2,S3,S4)
which dermatomes are responsible for the Bulbocavernosus reflex?
(S2,S3,S4)
what is the loss of the bulbocavenosus reflex seen in?
Spinal shock
Conus medullaris and Cauda equine lesions
describe the gross anatomy of the spinal cord?
About 45cm long and cylindrical in shape.
Starts from the foramen magnum and tapers into the conus medullaris, ending at L1–L2 in the adult at L3 in the newborn, and at S2 in the fetus.
Below the conus medullaris are found motor and sensory roots only (cauda equina), floating in the subarachnoid space before exiting though lumbar and sacral foramina.
Possesses a cervical (C5–T1) and a lumbosacral (L2– S3) enlargement for the brachial, lumbar, and sacral plexuses.
Has three columns of funiculi divided by the anterior median fissure ventrally, the posterior median sulcus dorsally, and the anterior and posterior nerve roots laterally.
On section, the butterfly or H-shaped centrally placed grey matter is surrounded by ascending and descending tracts
what type of sensation is the dorsal column responsible for?
Fine touch
Joint position
Vibration
Proprioception
what type of sensation is the lateral spino-thalmic tract responsible for?
Pain and temperature
what type of sensation is the anterior spino-thalmic tract responsible for?
Light crude touch
describe the different aspects of the dorsal column?
Meissner’s & pacinian corpuscles, free nerve endings.
heavily myelinated neurons
dorsal root ganglion
nucleus proprius (Rexed III & IV)
Ipsilateral posterior columns
nucleus gracilis (below T6)/cuneatus (above T6)
internal arcuate fibers, decussate in lower medulla
medial lemniscus
VPL thalamus
internal capsule
describe the different aspects of the lateral spino-thalmic tract?
free nerve endings
finely myelinated neurons
dorsal root ganglion
Substantia gelatinosa of rolandi (Rexed II)
Cross the midline in the anterior white commissure
Lateral spino-thalamic tract
VPL thalamus
Internal capsule
postcentral gyrus