Back Flashcards
(23 cards)
Back
Comprises posterior aspecg of the trunk Between neck and buttocks Components -skin and subcutaneous tissue -muscles=> superficial and deep -vertebral column -ribs -spinal cord and meninges -segmental nerves and vessels
Back osteology
Vertebral column -extends from cranium to apex of coccyx -it is 72-75cm long in adult *1/4 is formed by IV discs Functions to -protect spinal cord and spinal nerves -supports the weight of the body superior to the pelvis -involved is posture and locomotion
Vertebral movement
Is reduced to the superior 24 vertebrae
5 sacral are fused
4 coccygeal usually fuse after age 30
*limiting movement of these vertebrae
Vertebrae size
Become larger from cervical to sacrum and then become smaller from sacrum to coccyx
Initial increases in size is due to increased body weight bearing
*cervical=>thoracic=>lumbar=>sacrum=>pelvis=>legs
General characteristics of vertebrae
Body is cylindrical, anterior part that supports body weight
Vertebral arch posterior to VB
- 2 short cylindrical pedicles projecting posteriorly from body
- 2 short flat laminae placed continuous with pedicles that join posteriorly in the midline
Vertebral foramen formed by vertebral arch and posterior surface of vertebral body
-succession of vertebral foramina forms the vertebral canal
Lateral masses
Vertebral notches
There are 2 which are superior and interiors to each pedicle
Notches of adjacent vertebrae for intervertebral foramina
*exit for spinal nerves and accompanying vessels
Processes
Spinous process 1 process that is median and posterior
Transverse processes 2, that project postero-laterally from the junction of pedicles and laminae
Articulate processes 4, 2 superior and 2 inferior that project from the junction of the pedicles and laminae
*each bears an articular surface or facet
Cervical vertebrae
Located between cranium and thoracic vertebrae
Smallest of the movable vertebrae
*bear less weight
Greatest range and variety of movement of all vertebrae regions
-relative thickness of discs compared to the vertebral bodies
-nearly horizontal orientation of facets
-small amount of surrounding body mass
C1=Atlas=atypical vertebrae
Carries cranium
No body
Anterior/Posterior arch & tubercle
Articulate facet for dens=> on posterior surface of the anterior arch
Lateral masses=> bear weight of cranium
Transverse process=> project laterally and are relatively flat
Transverse foramen=> passage for vertebral arteries and accompanying veins
Superior articulate facet- articulates with occipital condyle
Inferior articulate facet- articulates with axis
Tubercle for Trans. Lig. of Atlas- the ligament that helps to hold the dens of C2 in place
Groove for vertebral artery- allows passage for vertebral artery into cranium
C2=Axis=Atypical vertebrae 1
Strongest of cervical vertebrae
C1 carries the cranium and rotates on the axis
Body
Dens- projects superiorly from the body and articulate with the posterior surface of the anterior arch of the atlas
*forms synovial joint
*embryologically the dens represents the remnants of the body of the Atlas
-AAF-articulates with posterior surface of anterior arch of atlas
-PAF-where the dens is supported by transverse ligament of atlas
C2=Axis=Atypical vertebrae 2
Pedicles
Lateral masses
Superior articulate facet is where the atlas rotates
Inferior articulate facet articulates with C3
Transverse process extends latero-inferior
Transverse foramen is the passage for vertebral arteries and veins
Laminae
Spinous process is bifurcated in Caucasians but not as common in blacks or females
C3-7=Typical vertebrae 1
Body
Transverse process
Transverse foramina=>vertebral artery goes through C3-6
*C1 has a groove or depression on its posterior tubercle for the vertebral artery.
C2 has grooves on its transverse processes. And the artery does not go through C7
Anterior/Posterior tubercle for muscle attachment
Pedicles and Laminae
Superior/Inf Art facets- more transverse plane to allow more articulation via gliding movement
C3-7=typical vertebrae 2
Vertebral foramen is triangular/large and contains large portion of spinal cord
Uncus of body raised lateral margins of the superior surface of cervical vertebrae C3-7
Spinous process is bifurcated
C7=vertebra prominens=> defines the inferior limit of the neck posteriorly
Thoracic vertebrae
Bodies, vertebral arches, and 7 processes for muscular and articulate connections
Costal facets=bilateral demifacets=>articulate with head of ribs
-usually occurs in superior and inferior pairs
Transverse costal facets => articulate with tubercles of ribs
Spinous processes=>long and slopes inferiorly
Lumbar vertebrae 1
Lower back between thorax and sacrum
Have bodies, vertebral arches, 7 processes for muscular and articular connections
-massive bodies that account for much of the thickness of the lower trunk in the median plane
Transverse pro=>accessory pro=>on posterior surface of the bar of the transverse pro, provides attachment for the intertranversarii muscles
Lumbar vertebrae 2
Sup Art Pro=> mammillary pro=> on posterior surface of the superior articular process
-provide attachments for the multifidus and intertransversarii muscles
L5 is the largest of moveanle vertebrae
Lumbosacral angle occurs at the junction of the long axis of the lumbar and sacral region
Sacral vertebrae
5 fused sacral vertebrae in adult between hip bones
Forms the roof and posterosuperior wall of the pelvic cavity
Provides strength and stability to the pelvis
-transmits the weight of the body to the pelvic girdle
Characteristics features of Sacral vertebrae 1
Sacral canal is a continuation of the vertebral canal in the sacrum
Ant/post sacral foramina exit for the anterior/post rami of spinal nerves
Median sacral crest is fused rudimentary spinous process of sacral vertebrae
Base of sacrum is superior surface if S1 vertebra
Sacral promontory anterior projection of the edge of the body of S1 vertebra
Characteristics features of Sacral vertebrae 2
Ala represents the fused transverse processes of sacral vertebrae
Apex is the inferior end that articulates with coccyx
Sacral hiatus is inverted and U-shape resulting from lack of laminae and spinous process of S5 vertebra
Sacral cornua represents inferior articular process of S5
-helps in anatomical location of the sacral hiatus
Coccygeal vertebrae
Usually 4 fused coxxygeal vertebrae
Remnant of the skeleton of the embryonic tail-like causal eminence
Does NOT participate in body weight bearing
Coccygeal cornua rudimentary articular process of Co1 vertebra that articulate with the sacral cornua
IV discs
Cartilaginous joint connecting articulating surfaces of adjacent VBs
-ALL is a strong broad fibrous band covering & connecting the anterolateral aspects of VB & IV discs
*extends from anterior aspect of FM to pelvic surface of sacrum
ONLY LIGAMENT TO LIMIT EXTENSION
-PLL is a weaker and narrower band than ALL
* runs within V canal along post aspect of VBs
*extends from body of C2 to sacrum
Zygapophysial joints (question) about ligaments
Synovial j btwn sup and inf articular facets of adjacent verts=>gliding movement
- ligamenta flava is broad yellow and if elastic tissue joining laminae of adjacent verts from post wall of V canal
- limit flexion and are for separation of V laminae protecting IV discs
- interspinous are weak ligs joining adjacent spinous processes
- inconsequential in the cervical region
- nuchal is strong broad thickened fibroelastic tissue
- extends from occipital protuberance and post border of FM to spinous processes of cervical verts for muscle attachment
Atlanto-occipital joint
Synovial j w/ thin loose capsule btwn sup articular facets of C1 and condyles of occipital bone for flex and extension
-anatomical equivalent to zygapophyial j
