Lecture 4: Part 2 (Spinal Column) Flashcards
Efferent (motor) only
- we are looking at an axial cut of the vertebral column
- the yellow structures are ventral (anterior) side of the spinal cord
-
so what is the ventral (or anterior) root modality?
-
efferent (motor) only
-
will mix with the dorsal (posterior) root (carrying sensory only) at the intervertebral foramen where it will mix as a spinal nerve
- then we will see a seperation of the two - a dorsal ramus going dorsally to supply the intrinsic muscles of the back and a ventral ramus to take care of the rest of the body at that particular vertebral level
-
will mix with the dorsal (posterior) root (carrying sensory only) at the intervertebral foramen where it will mix as a spinal nerve
-
efferent (motor) only
ventral/anterior root carries what?
ventral/anterior root carries efferent (motor)
dorsal/posterior root carries what?
dorsal/posterior root carries afferent (sensory)
where do modalities mix as spinal nerve?
modalities mix as spinal nerve at intervertebral foramen (both motor and sensory)
dorsal/posterior ramus carries what?
dorsal/posterior ramus carries mixed sensory/motor to intrinsic back muscles and skin overlying the midline of the back
ventral/anterior ramus carries what
ventral/anterior ramus carries mixed (motor and sensory) to every else (everywhere but the intrinsic back muscles and skin overlying the midline of the back)
2 primary spinal curves (in fetus)
- kyphotic = concave anteriorly
- thoracic and sacral
2 secondary spinal curvatures
(names and what causes each)
- lordosis = concave posteriorly
- occurs because bipedal
- cervical lordosis = due to raising and holding head erect
- lumbar lordosis = due to upright posture, standind and walking
we start as kyphotic fetus and maintain kyphotic curve in thoracic and sacral regions but gain lordodic curves as we mature
kyphosis (abnormality)
kyphosis = hunchback
- abnormal exaggeration of the thoracic curvature
Dowager’s Hump
Dowagers hump = excessive thoracic kyphosis in older women resulting from osteoporosis
Lordosis (abnormality)
- Lordosis = hollowback
- an abnormal exaggerated lumbar spine
- exaggerated lumbar lordosis = common in pregnancy or with increased abdominal fat anteriorly
scoliosis (abnormality)
- scoliosis = curved back
- abnormal lateral curvature of the spine, usually in the thoracic region
Increased pressure on the structure indicated by the arrows would diminish what functional modality(ies)?
A. efferent
B. afferent
C. both
Increased pressure on the structure indicated by the arrows would diminish what functional modality(ies)?
A. efferent
B. afferent
C. both
what are the most anterior and most posterior structures of spine
- most posterior structure = spinous processes
- __in every region except in the end of the sacral region where they fail to form and we get a sacral hiatus (gap)
- most anterior structure = vertebral bodies
- blocks of bone stacked next to each other (with intervertebral discs between them)
1 =
1 = vertebral body
2 =
2 = spinous process
3 =
3 = transverse process
4 =
4 = inferior articular process
5 =
5 = inferior articular facet
Typical Vertebra:
A =
Typical Vertebra:
A = spinous process
Typical Vertebra:
B =
Typical Vertebra:
B = vertebral body
Typical Vertebra
C =
Typical Vertebra
C = Lamina
Typical Vertebra
D =
Typical Vertebra
D = Pedicle
Typical Vertebra
E =
Typical Vertebra
E = Transverse Process
Typical Vertebra
F =
Typical Vertebra
F = Vertebral Foramen (canal)
Typical Vertebra
G =
Typical Vertebra
G = Superior articular process and facet
Typical Vertebra
H =
Typical Vertebra
H = Inferior articular process and facet
Typical Vertebra
I =
Typical Vertebra
I = Inferior vertebral notch
Typical Vertebra
J =
Typical Vertebra
J = Inferior vertebral notch
Typical Vertebra
K =
Typical Vertebra
K = Vertebral Arch
Typical Vertebra:
A =
Typical Vertebra
A = Vertebral Foramen
Typical Vertebra
B =
Typical Vertebra
B = Lamina
Typical Vertebra
C =
Typical Vertebra
C = Vertebral Body
Typical Vertebra
D =
Typical Vertebra
D = Transverse Process
Typical Vertebra
E =
E’ =
Typical Vertebra
E = Superior articular process (and facet)
E’ = Inferior articular process (and facet)
Typical Vertebra
F =
Typical Vertebra
F = Pedicles
Typical Vertebra
G =
Typical Vertebra
G = Spinous Process
Typical Vertebra
A =
Typical Vertebra
A = Vertebral Body
Typical Vertebra
B =
Typical Vertebra
B = Vertebral Arch
Typical Vertebra
C =
Typical Vertebra
C = Inferior Articular Process and Facet
Typical Vertebra
D =
Typical Vertebra
D = Superior Articular Process and Facet
Typical Vertebra
E =
Typical Vertebra
E = Transverse Process
Typical Vertebra
F =
Typical Vertebra
F = Spinous Process
Typical Vertebra
G =
Typical Vertebra
G = Lamina
Typical Vertebra
H =
Typical Vertebra
H = Pedicle
Typical Vertebra
I =
Typical Verebra
I = Vertebral Foramen/Intervertebral Foramen
Typical Vertebra
J =
Typical Vertebra
J = Superior Vertebral Notch
Typical Vertebra
K =
Typical Vertebra
K = Inferior Vertebral Notch
Typical Vertebra
L =
Typical Vertebra
L = Zygapophysial (facet) Joint - formed by inferior articular process and superior articular process of adjacent vertebra
Typical Vertebra
M =
Typical Vertebra
M = Intervertebral (IV) disc
Typical Vertebra
N =
Typical Vertebra
N = Epiphysial Rim (smooth bone derived from anular epiphyis)
Typical Vertebra
A =
Typical Vertebra
A = Vertebral Body
Typical Vertebra
B =
Typical Vertebra
B = Pedicle of the vertebral arch
Typical Vertebra
C =
Typical Vertebra
C = Lamina of the vertebral arch
Typical Vertebra
D =
Typical Vertebra
D = Superior articular process
Typical Vertebra
E =
Typical Vertebra
E = Inferior articular process
Typical Vertebra
F =
Typical Vertebra
F = Transverse Process
Typical Vertebra
G =
Typical Vertebra
G = Spinous Process
Typical Vertebra
H =
Typical Vertebra
H = Vertebral Foramen (canal)
Typical Vertebra Functions:
- Muscle attachment & movement = (2)
Typical Vertebra Functions:
- Muscle attachment & movement = Transverse and Spinous Process (blue)
- transverse processes = 2 side processes
- spinous processes = middle process
Typical Vertebra Functions
- Support of body weight (1)
Typical Vertebra Functions
- Support of body weight = Vertebral Body (purple)
- most anterior feature of typical vertebra
Typical Vertebra Functions
- Protection of spinal cord = (1 with 2 subparts)
Typical Vertebra Functions
- Protection of spinal cord = Vertebral arch - made of lamina and pedicles (red)
- pedicles = 2 “walls”
-
laminae = 2 sides of “roof”
- protect soft spinal cord that lies within the neural arch
Typical Vertebra Functions
- Restriction of Movement = (1 main part and 2 structures that make it up)
Typical Vertebra Functions
- Restriction of Movement = Facet (zygapophysial) joints
- Made up of Articular Processes - 2 inferior articular processes and 2 superior articular processes (yellow)
- restrict movement based on if at 90° or 45° angles
- Made up of Articular Processes - 2 inferior articular processes and 2 superior articular processes (yellow)
regional characteristics of cervical vertebrae
- what is unique about the spinous process?
- which cervical vertebrae have this?
- what other unique structure to cervical vertebrae have?
- why does this exist?
regional characteristics of cervical vertebrae
- what is unique about the spinous process?
- Bifid Spinous Process (C2-C6): the spinous process splits into 2 distally
- what other unique structure to cervical vertebrae have?
-
Transverse Foramen: a gap on each side of the transverse process which contains the vertebral artery and vein and a sympathetic nerve plexus.
- The sympathetic nerve fibers travel through the transverse foramen of C6-C1 before entering the foramen magnum (opening in the skull)
-
Transverse Foramen: a gap on each side of the transverse process which contains the vertebral artery and vein and a sympathetic nerve plexus.
1 =
2 =
3 =
4 =
5 =
6 =
7 =
8 =
9 =
Unique feature of thoracic vertebrae: _______ (2 different kinds)
- _______ (aka _____ ) on the transverse processes of vertebrae ___-___
- articulate with _____
- forms what joints?
- ________, with one on each side of the ______
- superior ______ artiulates with _______
- inferior ______ articulates with ______
- forms what type of joint?
Unique feature of thoracic vertebrae: costal facets (2 different kinds)
-
(Transverse) Costal Facets:
- on the transverse processes of T1-T10
- articulate with the tuburcles of the ribs at the same level
- Forms costotransverse joints
-
Demi-Costal Facets
- one on each side of the vertebral body
- superior demifacet artiulates with the tuburcle of the rib at the same level
- inferior demifacet articulates with the tuburcle of the rib below
- Form costovertebral joints
- one on each side of the vertebral body
features of lumbar vertebra
- what is unique about vertebral body?
- what is it missing (2)?
- unique relationship with spinal cord? (and unique articulation)
features of lumbar vertebra
- has larger body
- no transverse foramen or costal facets
- spinal cord terminates at L1; L5 articulates with the sacral promentory
Unique features of sacral vertebra
- what are the components?
- what 2 unique articulations do they have?
Unique features of sacral vertebra
- consists of 5 fused vertebrae
- S1 articulates with L5 and S5 articulates with coccyx
Atlas
- missing what 2 structures?
- 3 unique structures
- has a strong _______
Atlas (C1)
- has no vertebral body and spinous process
- Instead has two lateral masses, connected by anterior and posterior arches. Each lateral mass has a superior articular facet for articulation with occipital condylates in the head and an anterior articular facet for articulation with the dens (odontoid process) of C2
-
Anterior arch:
- contains anterior tubercle on the anterior aspect of arch, which is the site of attachment of the anterior longitudinal ligament.
- contains a facet for articulation with the dens (odontoid process) of C2
- secured by the transverse ligament of the atlas, which attaches to the lateral masses
-
Posterior Arch:
- contains paired grooves for the C1 spinal nerve and vertebral artery
- contains posterior tuburcle on the posterior aspect of the arch, which is attachment site for the ligamentum nuchae.
- 3 unique structures:
- Anterior/Posterior Arches
- Anterior/Posterior Tuburcles
- Lateral Masses
- has a strong Transverse Ligament
Axis
- unique structure: _______ (aka _____)
- projects up from ______ through ______
- articulates with ______ to form _____ joint; this allows for _____
- has no _____
- how was this structure formed during development?
Axis (C2)
- unique structure: odontoid process (aka dens)
- projects up from the vertebral body of C2 through the vertebral foramen of the atlas (C1)
- articulates with the anterior arch of the atlas cranially to form medial-atlanto-axial joint; this allows for rotation of head independent from torso
- no IV disc between C1 and C2
- how was this structure formed during development?
- dens = body of C1 fused to C2 during development
what is this showing? what view is it from?
-what are structures 1-4?
Plain films of normal lumbar spine - Frontal view
- pedicles
- spinous process
- facet (zygapophysial) joint - joints in film = bone + bone (white) with gap in between them (black)
- transverse process
What is shown in this film and what view is it from?
what are structures 1-5?
Plain Film of Normal Lumbar Spine - Lateral view
- pedicles
- spinous process
- facet (zygapophysial) joint - joints in film = bone + bone (white) with gap in between them (blac)
- vertebral body
- disc space - note how the height of the disc spaces increases from L1 to L5 with the exception of the L5/S1 disc space which is normally narrower than the one above.
Zygapophysial (facet) Joints formed by:
Zygapophysial (facet) Joints formed by: 1 inferior articular facet + 1 superior articular facet (from the more inferior vertebral body)
- show by number 3 in radiographs
what is shown in green and pink?
Surface Anatomy of neck
A =
Surface Anatomy of neck
A = external occipital protruberance
- a bony prominance on the external surface of the occipital bone (just below the hairline)
Surface Anatomy of Neck
B =
Surface Anatomy of Neck
B = Nuchal Groove (for nuchal ligament)
- groove below the external occipital protruberance (A) extending down to C7; contains nuchal ligament
Surface Anatomy of Neck
C =
Surface Anatomy of Neck
C = Vertebra Prominens (C7 spinous process)
- prominant eminance in the midline of base of neck, especially when neck is flexed
Surface Anatomy of Neck
What vertebra are D, E and F?
Surface Anatomy of Neck
D = T1
E = T2
F = T3
- We know this because C is the vertebra promimens = the spinous process of C7
Movement of Cervical Vertebra
- type of joint that allows/limits movement
- location of joint and what it’s formed by
- 3 types of movement
Movement of Cervical Vertebra
-
Zygapophysial (facet) joints = allow and limit movement
- in the gaps between spinous processes
-
formed by inferior articular facet (at that level) and superior articular facet (from vertebral body below)
- Flexion (forward): decreasing joint angle, or moving to an anterior approach (ie head to chest)
- Extension (backward) increasing joint angle, move neck in posterior approach (ie tilt head backwards to look at sky)
- Lateral flexion = side bending
Endochondral ossification (vertebral column)
- _____ surrounds the _____ and _____ to become the vertebrae and ribs
- It is then replaced by ________, which is replaced by ______
- This process is called endochondral ossification
Sclerotomal mesenchyme surrounds the neural tube & notochord to become the vertebrae and ribs.
It is replaced by cartilage, which is replaced by bone.
This process is called endochondral ossification.
what is important about endochondral ossification of the vertebral column?
- there are many primary ossification and chondrification sites, however the ossification center for the developing spinous process is very important
- it will close off the vertebal arch (aka the neural arch, shown in red) and closes the roof of our spinal cord (spinal cord is green star)
- if this primary center for ossification or chondrification does not occur, we can have issues with the stability of the spinal column itself (ie spina bifida)
Spina Bifida
- when a portion of the neural tube fails to close properly
- creates defect or absence of the vertebral arches due to failure of the mesoderm to organize over the region of the defect
- causes failure of spinous processes to ossify properly
- Spinous processes are the last part of vertebrae to ossify
- may or may not also involve the underlying meninges and neural tissue
Spina Bifida Occulta
- mildest and most common form of spina bifida
- caused by failure of the caudal aspect of the neural tube to close completely
- there is a small gap where vertebrae have incomplete closure, but no opening or sac on the back
- unfused vertebral arch exposes a little bit of the spinal cord (dura matter)
- otherwise meninges and spinal cord not effected
- the spinal cord is still contained within the spinal canal and there is no herniation of the contents
- people are usually asymptomatic, except for a tuft of hair or dimple at location of gap
Spina Bifida: Meningiocele
- There is a gap where vertebra failed to close arch (where the neural tube did not close during neurulation), but now there is herniation of some of the contents of the defect
- dura and arachnoid matter bulge outwards, creating a large cyst with incresed subarachnoid space that is filled with CSF
- only meningeal layer affected (the spinal cord and nerves still in place)
- can see bump on back at location of defect
Spina Bifida: Myelomeningeocele (aka meningiomyocele)
- like meningiocele, but with not only are the meninges herniated, but also the actual spinal cord itself herniated
- puts traction on the spinal ganglia and spinal nerves as you displace the entire spinal cord
- still covered with skin (closed)
- symptoms = bump on back, weakness/loss of sensation below effected area, loss of bladder control
- can be fixed with surgery
spina bifida: myeloschesis/racheschesis
- similar to meningomyocele, but lacks any kind of skin or meningeal covering over the herniated nervous tissue, so the escaped contents of the spinal cord are open to the enviornment without any tissue covering them
- “open spinal cord”
- usually associated with malformation of cord itself
- meninges are not even herniated because they did not completely form (as well as incomplete spinal cord itself)
- not conducive to life
what type of spina bifida can be detected in utero and how is this done?
- open defects (myeloschesis/racheschesis)
- when spinal cord exposed to amniotic fluid
- can be detected in utero by the prescence of alpha-fetoprotein in maternal blood
How many vertebral bodies are in each region?
- cervical
- thoracic
- lumbar
- sacral
- coccygeal
- cervical = 7
- thoracic = 12
- lumbar = 5
- sacral = 5 (fused)
- coccygeal = 4 (3-5 fused)
Vertebral notches
- one of the two _____ above (superior) and below (inferior) the _____ of a ______
- the notches of two adjacent vertebrae (plus the intervertebral disc) form an ______
Vertebral Notches (aka intertervertebral notch)
- one of the two concavities above (superior) and below (inferior) the pedicle of a vertebra
- the notches of two adjacent vertebrae (plus the intervertebral disc) form an intervertebral foramen
Vertebral arch
- aka what?
- consists of what?
Vertebral arch (aka neural arch)
- Consists of two pedicles (laterally) and two laminae (posteriorly)
Vertebral foramen
- aka what?
- consists of what?
Vertebral foramen (aka vertebral canal)
- consists of vertebral arch (aka neural arch) and vertebral body
- vertebral foramen is the central space between the vertebral arch and vertebral body
- contains the spinal cord, nerve roots, meninges, and blood vessels
- adjacent vertebral foramina form the continuous vertebral canal extending from the foramen magnum to the sacral hiatus.
Articular processes & facets
- each vertebrae has ___ superior and ____ inferior articular processes that spring from the junctions of the ____ and _____
- what do these processes articulate with and form?
- what are articular facets?
Articular processes & facets
- each vertebrae has 2 superior (teal) and 2 inferior (red) articular processes that spring from the junctions of the pedicles and laminae
- superior articular processes project upward (toward the head), and their articular surfaces (facets) are directed more or less backward
- inferior articular processes project downward (toward the tailbone/coccyx), and their surfaces (facets) look more or less forward
- the superior articular process of one vertebra and the inferior articular process of the vertebra directly above it articulate to form a zygapophyseal or facet joints (synovial joints) (neon green)
- There are two facet joints in each spinal motion segment
- The facet joints are situated between the pedicle and lamina of the same vertebra and form the articular pillars that act to provide structural stability to the vertebral column as a whole
- articular facets (purple) = the flat surface at the end of superior and inferior articular processes where they articulate
spinous process
Spinous process
- single posterior midline process emerging at the junction of the two laminae
Transverse processes
- emerging at the junction of the ____ and ____ on each side
- transverse processes of the lumbar vertebrae are also called ______
Transverse processes
- Postero-lateral processes emerging at the junction of the pedicles and laminae on each side
- the transverse processes of the lumbar vertebrae are also called costal processes.
Atlas
Is missing what 2 structures? Instead has structures 1 and 2
1. has two ______
- on the inferior surface, each has ______ which articulates with ______ to form ______ joint
- on the superior surface, each has ______ which articulates with ______ to form _______ joint
2. has anterior and posterior ______
- anterior:
- on the posterior surface, has a facet that articulates with ______; this is strengthened by the strong ______ (which attaches to the _____ )
- has a _______ that attaches to ______
- posterior: (corresponds to the _____ on a typical vertebra)
- on it’s superior side, has a _____ for _____ and _____
- has a _____ that attaches to _____
3. Transverse processes (or facets): each have _______ where _____ runs through
Atlas
Is missing what 2 structures? Instead has lateral masses and anterior/posterior artches (structures 1 and 2)
- has two lateral masses
- on the inferior surface, each has an inferior articular facet/process, which articulates with the superior articular facets of C2 to form atlanto-axial joint
- on the superior surface, each has a superior articular facet/process which articulates with the occipital condyles to form the atlanto-occipital joint
- has an anterior arch and a posterior arch
- anterior arch:
- on the posterior surface, has a facet that articulates with the dens (odontoid process) of C2; this is strengthened by the strong transverse ligament of the axis (which attaches to the lateral masses)
- has an anterior tuburcle that attaches to the ALL
- posterior arch: (corresponds to the lamina on a typical vertebra)
- on it’s superior side, has a groove for the vertebral artery and C1 spinal nerve
- has a posterior tuburcle that attaches to the ligamentum nuchae
- Transverse processes (or facets) each have a transverse foramen where the vertebral artery runs through
what type of spina bifida is shown in each image?
