Back And Spinal Cord Flashcards
At what level does the spinal cord extend to in adults
L1/L2
Name the three layers covering the CNS
Meninges made up of dura mater, arachnoid mater and pia mater
What is the filum terminale
Extension of the pia mater that extends from the conus medullaris to anchor the spinal cord to the coccyx
What passes through an intervertebral foramen
Spinal nerves
What occupies the vertebral canal below L2
Cause equina
What do the dorsal rami of a spinal nerve supply
Motor supply to posterior muscles of the back eg erector spinae and posterior part of the dermatome - sensation to posterior skin
How man bones are fused to form the sacrum
5
Which vertebra has an odontoid peg
C2 the axis
What type of joint includes the intervertebral disc
Symphysis or secondary cartilaginous
Which major muscle antagonizes flexion of the vertebral Colombian and therefore allows movement to occur in a controlled manner
Erector spinae
At each spinal segment which branch of the spinal nerve would you expect to contain most axons and why
Ventral, supplies all the lateral region aswell as anterior. Dorsal Ramos only supplies the back
What types of somatic nerve fibers will be present in the dorsal ramus of the spinal nerve
Somatic motor and sensory
From which spinal nerve segments do preganglionic sympathetic motor nerves emerge from the spinal cord
T1-L2
What is meant my the term lordosis
Convex anterior curvature (term used clinical to describe exaggerated and therefore abnormal curvature although the term used in anatomy to describe the normal convex anterior curvature found the the lumbar and cervical regions)
What is meant by the term scoliosis
Lateral curvature of the vertebral column (always abnormal)
Which nerves contribute to the lumbar plexus
L1-L4
What is the difference between the autonomic nerve arc and the somatic nerve arc
A somatic arc contains an interneuron in the spinal cord
What occupies a dorsal root ganglion
Cell body of sensory pseudounipolar neuron
A horizontal line drawn between the left and right iliac crests transverse the vertebral column at which level
Spinous process of L4
IVD between L4/L5
Useful landmark when performing a LP or epidural
How do cervical vertebrae vary
Bifid spinous process Foramen transversarium (vertebral artery)
How does the thoracic vertebrae vary
Long inferiorly directed spinous process overall ping sub-adjacent vertebral body to restrict posterior extension.
Small circular vertebral canal
Costal articulation with ribs
How do lumbar vertebrae vary
Large vertebral body
Short horizontal spinous process
How do sacral vertebrae vary
Triangular bone formed by fusion of 5 vertebrae
What type of joint in the vertebrae-IVD-vertebrae joint
Symphyses
The majority of vertebrae also articles with each other at a synovial joint what is the name of this joint?
Zygapophysial (facet joints)
Between the adjacent superior and inferior articulation facets
What does the IVD consist of
Anulus fibrosis: fibrocartilage forming the circumference of the disc
Nucleus pulposus: central core of IVD, lies closer to the posterior surface of the dice and more liable to posterior herniation when the disc is damaged (no support from longitudinal ligaments)
What is the name of the joint between the skull and C1
What type of joint is this
What movement occurs here
Atlanto-occipital joint
Synovial, condyloid joint
Nodding of the head
Neck flexion and extension, little lateral flexion
What is the name of the joint between C1 & C2
What type of joint is this
What movement occurs here
Atlanto-axial joint
Synovial, pivot joint
Rotation
What are the ligaments of the vertebral column
Posterior and anterior longitudinal ligament (run the full length of the vertebral column and strengthen the vertebral body joints) anterior is thicker
Ligamentum flavum - extends between the lamina of adjacent vertebrae (alternating sections)
Interspinous and supraspinous ligaments - join the spinous processes of adjacent vertebrae (interspinous attach between processes and supraspinous attach to the tips)
Intertransverse ligaments - extend between transverse processes
Ligaments associated with stabilizing C2, C1 and occipital joints are the cruciate ligaments and alar ligament, what are there functions
Cruciate ligament: holds together posterior dens of C2 in articulation with the Atlanto-axial joint
Alar ligament - extend from sides of the dens to the lateral margins of the foramen magnum, attach cranium to C2 and prevent excessive rotation
Why does the spinal cord stop before the vertebral column ends
Because the spinal cord is shorter than the vertebral column the lower spinal nerve roots descend within the vertebral canal before leaving through their intervertebral formamina
At what level does the spinal cord terminate in an adult
L2
What is the conus medullaris
The terminal end of the spinal cord
What is the cause equina
Collections of nerves at the end of the spinal cord. Lumbar sacral and cocygeal nerve roots that continue out from the end of the spinal cord in the lumbar region
What is the filum terminale
Extension of the pia mater that extends from the terminal end of the spinal cord to the coccyx
What does the filum terminale attach to and what purpose does it have
The coccyx, serves as an anchor for the inferior ends of the spinal cord and dura sac
What are the two enlargements of the spinal cord and where are they
Cervical enlargement: C4-T1 brachial plexus inner gates the upper limbs
Lumbosacral enlargement: L1-S3 lumbar and sacral plexus (lower limbs)
What are the names of the 3 meningeal layers (deepest - superficial)
Pia mater
Arachnoid mater
Dura mater
What cranial nerves contain parasympathetic nerves
3, 7, 9, 10
What sacral nerves contain parasympathetic nerves
S2-S4
Chart the course of the vagus nerve
Originated from the medulla, exits cranium via jugular foramen, terminates in the abdomen by dividing into branches that supply oesophagus, stomach, SI, LI up to splenic flexure
Chart the course of the pelvic splanchnic nerves
Arise from S2,S3 & S4 nerve roots of the sacral plexus. They anastomoses with one another and ascend to join the ipsilateral hypogastric plexuses. Once reach the plexuses they ratify throughout the pelvis and lower abdomen inervating ganglia embedded in walls of descending, sigmoid colon, rectum uterus, prostate bladder urethra and penis
At what stages of development to the curvature of the vertebral column develop
Kyphosis (primary) foetal development
Lordosis (secondary) infant
Erector spinae is a long cylindrical group of muscles, located deep on the posterior back lying between the spinous and transverse processes on each side.
What movement does I bring about if both L and R muscle compartments contract bilaterally
What about if only one contracts (unilaterally)
Bilaterally: extend vertebral column and head as back is flexed. Control movement by gradual lay lengthening their fibers
Unilaterally: lateral flexion
What are the large superficial muscles of the back
Trapezius
Latissimus dorsi
Rhimboid major
Rhomboid minor
What is meant by disc prolapse
Annulus fibrosis develops an area of weakness which allows gelatinous nucleus pulposus centre to herniated an can press upon and trap a spinal nerve
