Spinal Bio I test 2 Flashcards
What are the four descriptive regions of the Occipital Vertebra?
- Basi-Occiput
- Squamous
3/4. L/R Lateral portions
What shape is the occipital vertebra?
Trapezoidal
Describe the Embryologic Formation of the Occiput
Ring around Foramen Magnum derived from the top 1/2 of cranial primary sclerotome
Homologous to a C1 embedded into the base of the skull
The internal part of the occiput is what shape?
Concave
The external part of the occiput is what shape?
Convex
What are 5 points that describe the Basilar/Basi-Occiput Portion of the Occiput?
- Everything anterior to the Foramen Magnum
- Articulates with the Sphenoid Bone and L/R Temporal Bones
- Distinct Trapezoid outline (x-ray landmark)
- Pharyngeal Tubercle
- Internal Surface
Describe the Pharyngeal Tubercle
On Basilar Portion of Occiput
“small bump”
Located in the mid-external basion
Attachment for the Longus Capitus Muscle
Describe the Internal Surface of the Basilar Portion of the Occiput
Smooth Deeply concave Featureless Supports Anterior Medulla Oblongata Penetrated by several small foramina (transmit CN)
3 Main points about the Lateral Portions of the Occiput
- Everything Lateral to the FM
- Articulates with L/R Temporal bones and C1 below
- Occipital Condyles
What and where are the occipital condyles?
2 oval bony projections
Lateral to the anterior 1/2 of FM
What do Long Axes do and form?
Converge anteriorly
Form L/R “Angles of Condylar Convergence”
- May be asymmetrical
- Vary widely person to person
What forms the Angles of Condylar Convergence?
Long Axes
6 Points about the Condylar Articulation surfaces
- Smooth, clearly marginated surface
- Actual point of articulation with C1
- Kidney shaped and convex along long and short axis
- Covers entire bottom of condyle
- FACE INFEROLATERALLY
- Both slope and convexity are highly variable and may be asymmetrical
In which direction do the Condylar Articular Surfaces face?
Inferolaterally
Where does the Longus Capitus Muscle attach?
Pharyngeal Tubercle of the Basilar Portion of the Occiput
What supports the Anterior Portion of the Medulla Oblongata?
Internal Surface of the Basilar Portion of the Occiput
What articulates with the R/L Temporal bones and C1
Lateral Portion of Occiput
What articulates with the L/R Temporal Bone and the Sphenoid Bone?
Basilar Portion of the Occiput
Where are the Alar Ligaments attached?
Condylar Tubercles of Lateral Portion of Occiput
3 points about Condylar Tubercles
- Located on Medial Condylar Surface
- Project into FM
- Attach Alar Ligaments
3 points about Condyloid fossae
- Shallow Depression Posterior to the condyles
- Receieve posterior lips of the lateral masses
- Prevents bony “kissing” in hyperextension
What prevents bony kissing in hyperextension?
Condyloid Fossas
3 points about the Jugular Process
- Tabs of bone lateral to the condyles
- Named for Jugular notch, foramen, vein
- Homologous to C1 TP’s
What is Homologous to C1 TP’s?
Jugular Process of the Lateral Portion of the Occiput
What portion of the occiput is penetrated by several small foramina (transmit CN)?
Lateral Portion
5 Points about the Squamous Portion of the Occiput
- Everything Posterior to the FM
- Articulates with Parietal Bones
- External Surface
- Internal Surface
- Foramen Magnum
External Occipital Protuberance
EOP
Large tubercle in the middle of the external squamous portion
Easily palpated on the posterior skull
Attachment for Nuchal Ligament
Medial Nuchal Line
Attachment for Nuchal Ligament
Prominent bony ridge from FM to EOP
Nuchal= posterior neck/head region
Highest Nuchal Line
Faint/ indistinct body ridge
Project Superolaterally from EOP
Attach Occipitalis m.
Recognized and named later
Superior Nuchal Line
Projects laterally from EOP
Attach Trapezius and Splenius Capitus M.
Prominent, easily palpated body ridge
L/R
Inferior Nuchal Line
L/R
Projects laterally from Median Nuchal Line midway btw FM and EOP
Attach RCP Major and Superior Oblique m.
Prominent body ridge
Hard to palpate b/c under the “occipital shelf”
What are the 3 Occipital Plana?
- Planum Occipitale
- Superior Nuchal Plana
- Inferior Nuchal Plana
Where do the Trapezius and Splenius Capitus Muscles attach?
Superior Nuchal Line
Where does the Occipitalis m attach?
Highest Nuchal Line
Where does the Nuchal Ligament attach?
EOP
Median Nuchal Line
Where do the RCP Major and Superior Oblique m attach?
Inferior Nuchal lines
What is above the Highest Nuchal Line?
Planum Occipitale
3 points for Planum Occipitale
- Above the Highest Nuchal Lines
- Underlies scalp
- Smooth and featureless
What is between the Superior and Inferior Nuchal Lines?
Superior Nuchal Plana
3 Points for Superior Nuchal Plana
- L/R
- Btw Sup/Inf Nuchal Lines
- Attach Semi-Spinalis Capitis m
Where does the Semi-Spinalis Capitis m attach?
Superior Nuchal Plana
3 Points for the Inferior Nuchal Plana
- L/R
- Btw the FM and Inferior Nuchal LIne
- Attach RCP Minor m
Where does the RCP Minor m attach?
Inferior Nuchal Plana
3 points on the Internal surface of the Squamous portion of the occiput
- Deeply concave (cradles posterior lobes of brain)
- Cruciate Eminence
- IOP (Internal Occipital Protuberance)
Describe 5 points about the Cruciate Eminence
- 2 prominent perpendicular ridges
- Attachment for internal membranes
- Divides internal surface into 4 fossae
- L/R Superior Fossae cradle
- L/R Inferior Fossae cradle
What do the L/R Superior Fossae Cradles hold?
Occipital lobes of the cerebrum
What do the L/R Inferior Fossae Cradles hold?
L/R lobes of the cerebellum
4 Points about the IOP
- Intersection of the Cruciate Eminence
- Directly internal to the EOP
- Up to 3/4” thick (1/4”everywhere else)
- Smooth, featureless (cradles and supports brain tissue)
What is at the intersection of the Cruciate Eminence?
IOP
What is directly internal to the EOP?
IOP
What is the largest bony foramen in the skull?
FM
What is the 3rd largest body foramen in the skeleton?
FM
1/2= L/R Obturators
What is the FM shaped like?
Pinched oval
What passes the spinal cord from the skull to the spine?
FM
What are the 5 main points for the FM?
- Largest Bony Foramen in Skull
- 2nd largest Foramen in Skeleton
- Pinched oval shape
- Passes spinal cord from skull to spine
- Divided into 2 regions- post + ant
Describe the shape of the posterior portion of the FM
Larger
Round Portion
What passes thru the Posterior Portion of the FM?
Spinal Cord
Describe the shape of the Anterior portion of the FM
Smaller
Square Portion
What does the Anterior Portion of the FM accommodate?
Odontoid Ligaments
What is the boundary between the Anterior and Posterior Portion of the FM?
Condylar Tubercles
What are 5 typical characteristics of a cervical vertebra?
- Small, irregular vertebra
- 3 Foramina
- Bifid Spinous Process
- Uncinate Processes
- Body
What are the 3 Foramina in a typical cervical vertebra?
- Neural/ Vertebral Foramen (1)
2. L/R Transversarii Foramen (2)
What is the typical shape of a Cervical Vertebral Body?
Wide Oval
Rectangular Cylinder
What are 3 points for the Inferior Epiphysis of the Typical Cervical Vertebra?
- Concave AP
- Prominent Anterior Lipping
- Slight Posterior Lipping
What part of the Cervical Vertebra has an Uncinate Process?
Superior Epiphysis
What are the 3 points for the Superior Epiphysis?
- Uncinate Processes (prominent lateral lips)
- Slight posterior lipping
- Form Unco-Vertebral Joints
Describe Unco-Vertebral Joints
Articulate with sides of inferior epiphysis above
AKA JOINTS OF VON LUSHKA
Unique to cervical spine
DOESN’T involve anterior lipping of inferior epiphysis
3 points of the posterior surface of a typical cervical vertebral body
- Basi-Vertebral Foramina/men
- Exit for the Base-Vertebral Veins
- Arteries enter through small “Nutritive Foramen”
What are short, horizontal cylinders of bone on a typical cervical vertebra?
Pedicles
These project posterolaterally from the corners of the body of a cervical vertebra
Pedicles
Describe the Pedicle notches of a cervical vertebra
Approximately equal Superior/Inferior Notches
What forms the Cervical IVF’s
Pedicle notches
What are the shape of the Cervical IVF’s
Square with rounded corners
How do you view Cervical IVF’s?
Seen on Cervical Obliques Only (ipsilaterally)
What are the 2 lateral cylinders at the LPJ?
Articular Pillars/ Columns
Cervical Pre-Zygapophysis
Superior 1/3
Project upward from LPJ
SAS
The Cervical SAS’s Face…
Posterosuperior, slightly Medial
In lower cervs: more Posterior, slightly Lateral
What are the shape of Cervical SAS’s/ IAS’s?
Round/Oval
Smooth
Flat
Cover entire surface of the articular pillars
What is the middle 1/3 of the articular pillars?
Pars Interarticularis
Narrow, Constricted middle
Pedicles attach Anteromedially
Lamina attach Posteromedially
Cervical Post-Zygapophysis
Inferior 1/3
Project downward from LPJ
IAS
The Cervical IAS’s face…
Anteroinferior, slightly Lateral
In lower cervs: more Anterior, slightly Medial
Long, thin, vertical plates of bone on a Cervical Vertebra?
Laminae
What projects Posteromedially from the Articular Pillars (Cervs)?
Laminae
What do the Laminae do?
Meet and fuse in the midline= line of interlaminar fusion
Becomes spinous base
Form Posterolateral walls of neural canal
What part of a Cervical Vertebra is short and delicate?
Spinous Process
How do Cervical Spinous Processes project?
Posterior and slightly Inferior
What are the ends of SP’s in Cervicals?
Bifid Tips
2 Posterolateral L/R Distal Spinous Tubercles
Are the SP’s in the cervicals easy or hard to palpate?
Hard within Lordotic Curve
What is the Anomaly that may occur in Cervical SP’s?
Often missing bifid tip (aplasia or non-ossification)
What projects anterolaterally in a cervical vertebra?
TP
AKA’s for Anterior TP in Cervical Vertebra?
False
Costo-Transverse
How do the Anterior TP’s project in Cervical Vertebra?
Anterolaterally from the body
What is the end of an Anterior TP in Cervical Vertebra?
Anterior Distal Transverse Tubercle
What are Anterior TP’s homologous to?
Ribs
What is on the Anterior TP of C6?
Carotid Tubercles
AKA for Posterior TP?
True TP
What projects Anterolaterally from the Articular Pillars of a Cervical Vertebra?
Posterior/True TP
How do the Posterior TP’s run?
Parallel to Anterior TP
What do the Posterior TPs end in?
Posterior Distal Transverse Tubercle
What is the thin horizontal plate of bone in the cervical vertebrae that forms a trough like floor?
Costo-Transverse Lamella
What do the Costo-Transverse Lamella Do?
Connect the inferior portions of the Anterior and Posterior TP’s distally
What is the large round hole through the Cervical TP’s?
Foramen Transversarii
