Ch.1 - Spinal Osteology 9/17 Flashcards
1
Q
Total number of vertebrae/sections
A
33 - 7 cervical - 12 thoracic - 5 lumbar - 5 sacral (fused) - 4 coccygeal (usually fused)
2
Q
different sacral fusion patterns
A
- sacralization: fusion of the fifth lumbar vertebra with the sacrum - lumbarization: lack of fusion of the first sacral vertebra with the sacrum
3
Q
Vertebral Body
A
- largest most anterior portion - cylindrically shaped having roughened ends covered with hyaline cartilage - composed of spongy (cancellous) bone covered with a thin layer of compact (cortical) bone; when demineralization of the spongy bone takes place, the structural integrity of the vertebra is compromised resulting in compression fractures
4
Q
Vertebral Arch: composed of 2 things…
A
- Pedicles: posterolateral processes which project from the body bilaterally
* (Vertebral notches): superior and inferior indentations of the pedicle When articulated these indentations on contiguous vertebrae help form intervertebral foramina which allow for the passage of the spinal nerves and vessels - Laminae: continuation of pedicles posteromedially; fuse in the midline to complete the vertebral arch and enclose the vertebral foramen
5
Q
Transverse process
A
bilateral extensions of bone directed lateralward from the junction of the pedicle and lamina
6
Q
Articular processes
A
- four per vertebra
- two inferior, two superior
- located at the junction of the pedicle and lamina
- location of the articular facets determines regional movement
7
Q
Spinous Processes
A
-posteriorly directed extension of bone formed by the union of two laminae
8
Q
Typical Cercical
A
1- Vertebral Body: Small; later dimension is greater than anterior/posterior dimension
2- Transverse Process:
- arises from the junction of the pedicle and articulating processes
- directed anterolateral
- they are anteriorly attached to costal processes which project from the body of the vertebra therby forming the costotransverse foramen (transverse cervical foramen) = foramen transversarium
- Costal and transverse processes end laterally forming anterior and posterior tubercles which provide sites for attachment of neck and superficial back musculature
The osseous connection between the costal process and transverse process is grooved on its superior surface for passage of the spinal nerve
3- Articulating processes:
- located posterior to the transverse
- facets are flat and oval shaped and oriented obliquely in the coronal plane
- superior facets are directed upward and backward
- inferior facets are directed downward and forward
4- spinous process:
- short, bifid, downward projecting
5- Vertebral arch/Foramen:
- Triangularly shaped with apex direced posteriorly
9
Q
Atlas
A
CV1
- does not posess a body, instead it is constructed of two lateral masses connected by anterior and posterior arches
1. Anterior Arch: tubercle, facet for dens of CV2 (dens)
2. Posterior Arch: tubercle, sulcus for vertebral artery
3. Large articulating facets: - superior: articulate with the occipital condyles of the skull
- inferior: articulate with the superior articulating facets of the axis
- transverse process: well developed to provide attachment sites for muslces which rotate the head
10
Q
Axis
A
- CV2
- body of CV2 incorporates the body of CV1 as the odontoid process (dense)
- dens has smooth anterior articulating facet which receives the anterior arch
- superior articulating facets are modified to articulate with CV1
- spinous process is thick and bifid
11
Q
Vertebra Prominens
A
- CV7
- represents a transition between cervical and thoracic regions
- long, nearly horizontal spinous process is easily palpable
- transverse foramina are smaller and frequently absent; when present DO NOT transmit the vertebral artery, but do transmit the vertebral vein
12
Q
Thoracic vertebra
A
- Body:
* heart shaped; intermediate size - Costal Facets: 2 per side
- Superior Costal Facet: at the origin of the pedicle
- inferior costal facet: at the lower edge of the vertebra immediately anterior to the inferior vertebral notch
- Note: Costal facets (Demi facets) of contiguous thoracic vertebrae form a “cup shaped” receptacle for the head of the rib (TV1,10,11,12 are considered atypical because they have complete superior costal facets for the head of the corresponding ribs)\
- Articulating Processes:
- Located at the junction between the pedicle and lamina
- thin and flat
- oriented vertically in the coronal plane (allows for sidebending)
- superior facets face posteriorly, superiorly and somewhat laterally
- inferior facets face anteriorly, inferiorly, and somewhat medially
- Transverse Process:
- Thick, strong and long
- directed posterolateral
- facet on its anterior surface is for articulation with the costal tubercle
- Laminae: overlap like roofing shigles
- Spinous Processes:
- overlap one another
- directed inferiorly
- Vertebral Foramen:
- circular
- most narrow diameter of the entire column
13
Q
Lumbar Vertebra: describe body, pedicles, transverse processes, laminae, spinous process, mamillary processes, vertebral foramen
A
- Body: increased in size due to increased weight bearing capacity
- Pedicles: are strong, short
- Transverse processes: lie anterior to articulating processes; directed laterally
- Laminae: Short and non-overlapping; facilitate lumbar puncture
* Pars Interarticularis = area of lamina between superior and inferior articulating processes - Spinous processes: thick and strong
* project directly dorsalward to provide area for erector spinae muscle attachment - Mammilary Processes: provide muscular attachment sites on the posterolateral surface of the superior articulating process
- Accessory Mammillary processes: provide muscular attachment sites between the transverse process and superior articulating process
- Vertebral Foramen: triangularly shaped with the apex directed posteriorly
14
Q
Superior Surface of Sacrum
A
Promontory: shelf which presents a sharp anteriorly facing edge
15
Q
Lateral Sacral Surface
A
- Ala: fused costal and transverse process of SV1 (ala = wing)
- Auricular Surface (shaped like an ear): anteroloateral surface of ala; articulates with ilium and os coxa
