The Back 8.13 Flashcards
N164
Know it?
Vertebrae in adults
26 vertebrae (adult): • 7cervical • 12thoracic • 5lumbar • 1sacral • 1coccygeal
Function of intervertebral discs
- Absorb shock
- Permit movement between adjacent vertebrae
Effect of hydration on IV discs
Increase with hydration (most in AM, hence greatest height in morning)
N168
Know it? Anterior ligament, post. longitudinal ligament, ligamentum flavum, interspinous ligament, supraspinous ligament
Typical site/type of herniation
Post-lateral, lumbar (due to posture, compression, falls) in L4-L5 or L5-S1, cervical (movement)
Differentiation between vertebrae
Lumbar - Big body, short spinous processes
Thoracic - Costal facets for rib articulations
Cervical - Foramen in transverse processes (for vertebral arteries), small bodies
Atlas
Vertebra C1, also called the Atlas, is unique in that it has neither a body nor a spinous process. This ring‐shaped bone has paired lateral masses that serve the place of a body by bearing the weight of the globe‐like cranium.
Axis
Vertebra C2, also called the Axis, is the strongest of the cervical vertebrae. The distinguishing feature of the axis is the blunt tooth‐like dens (odontoid process), which projects superiorly from its body.
Primary Curvature
Resembles the fetal curvature (sacral and thoracic)
Secondary Curvature
develop as baby lifts head (cervical vertebrae remodeling) and then when the toddler begins to stand and walk (lumbar vertebrae remodeling)
Kyphosis
Curve in cervical region (“hump”)
Lordosis
Curve in lumbar region (normal in pregnancy)
Scoliosis
Curve favoring a side in T/C region
Symphysis
Joint between two vertebrae. The joints of the vertebral bodies are symphyses (secondary cartilaginous joints) designed for weight bearing and strength.The articulating surfaces of adjacent vertebrae are connected by IV discs and ligaments
Facet
Joint between bony aspects in vertebrae. The zygapophyseal (facet) joints are formed by the articulating processes of adjacent vertebrae.These processes determine the types of movements permitted and restricted between the adjacent vertebrae of each region. The articular processes also assist in keeping adjacent vertebrae aligned, particularly preventing one vertebra from slipping anteriorly on the vertebra below.
Flexion in back
Bend-over, toe touch
Extension in back
Backwards back bend (think Corrine in that music video)
Lateral flexion in back
Bending down to one side only
N176
Know it? Vertebral arteries, subclavian arteries, anterior spinal arteries, posterior spinal arteries
The anterior and posterior spinal arteries arise from… and supply…
…the vertebral arteries and supply the spinal cord
Posterior spinal artery feeds _ systems and anterior feeds _ systems
Posterior - sensory
Anterior - motor
N177
Know it? Poster and anterior spinal arteries
Vasculature of spinal cord - what feeds what portion?
Anterior Spinal Artery (1)
• arises from vertebral arteries and unite to form a single artery which travels midline of spinal cord and supplies anterior 2/3 of the cord.
Posterior Spinal Arteries (2)
• arise from vertebral arteries and travel just posterior to the dorsal horn of the spinal cord (bilateral) and together supply the remaining posterior 1/3 of the spinal cord.
What veins transport venous blood for the vertebral canal? What do they communicate via?
The internal (epidural) and external venous plexuses transmit venous blood inside and outside of the vertebral canal, respectively. The two plexuses communicate via intervertebral foramina.
N178
Know it?
Special quality of vertebral veins
No valves (significance in cancer - tumor metastasis)
Function of trapezius
Raise/lower scapula
Function of rhomboids
Retract scapulae together
Trapezius innervated by…
Accessory nerve
Lat. Dorsi innervated by…
Thoracodorsal nerve
Levator scapulae and rhomboids (ma. and mi.) innervated by…
Dorsal scapular nerves
N171
Know it?
N183
Know it?
N180
Know it? Serratus post. inf/sup, splenius (cap/cerv), semispinalis capitis
Serratus posterior superior/inferior function as…
Accessory muscles of respiration
Erector spinae muscles
Spinalis muscle
Longissimus m.
Iliocostalis m.
Erector spinae muscles function to…
Bilaterally: extension of spine Unilaterally: lateral flexion of spine
N181
Know it? Acc. muscles of respiration and erector spinae
Spinal cord enlarges at…
C/L region (to accommodate for extremities)
Site of LPs (ped and adult)
Between L1/L2 in adults, L4/L5 in babies - aims for cauda equina
Meninges
– Dura mater
• Dural sac
"tough"
– Arachnoid mater
– Pia mater
• Denticulate ligaments
• Filum terminale
– Internal and external portionsCSF is located…
…in the subarachnoid space between arachnoid and pia.
Spinal dural sac
- The dura mater forms the spinal dural sac, a long tubular sheath within the vertebral canal
- This sac adheres to the margin of the foramen magnum of the cranium, where it is continuous with the cranial dura mater (around brain)
Filum Terminale Externa
The pia mater extension within the dural sac is know as the filum terminale interna
• As the filum terminale interna reaches the end of the dural sac, it is joined by the dura and the filum terminale externa is formed which anchors the spinal cord and meninges to the coccyx
Why are anterior herniations uncommon?
Anterior ligament fortifies the front
Which nerve is affected in herniation?
Corresponding in lower C-vert, higher in T/L-vert
Triangle of auscultation
The site on the back where breath sounds may be most easily heard through a stethoscope
Boundaries: Latissimus dorsi, trapezius, medial border of scapula
Spondylolysis
Fracture of isthmus
Spondylolisthesis
Fracture and translocation of isthmus
