RA3 Spine Anatomy Flashcards
Label the 4 curvatures of the spine:
- Name
- Primary or secondary curvature
- Cervical curvature (secondary)
- Thoracic curvature (primary)
- Lumbar curvature (secondary)
- Sacral/coccygeal curvature (primary)
How many vertebrae is the spine made up of?
33 vertebrae
Label the 5 regions of the vertberal colum:
1. Name
2. Number of vertebrae
Label the parts of a typical vertebra
- Vertebral body
- Vertebral arch
- Vertebral foramen
- Pedicle
- Lamina
- Spinous process
- Transverse process
- Superior and inferior articular processes
- Superior and inferior notches
Label the 5 regions of the vertberal colum:
1. Name
2. Number of vertebrae
Extrinsic vs intrinsic muscles:
1. What muscle group (superficial, intermediate, deep)?
2. What structures do they move?
3. What type of spinal nerve are they innervated by?
Extrinsic muscles:
1. Superficial and intermediate groups
2. Upper limbs, thoracic wall/ribs
3. Anterior rami
Intrinsic muscles:
1. Deep group
2. Back, vertebral column, head
3. Posterior rami
Label the 3 layers of the meninges surrounding the spinal cord
- Pia mater: innermost membrane
- Arachnoid mater: borders the subarachnoid space, which contains cerebrospinal fluid
- Dura mater: thickest, outermost membrane
How many pairs of spinal nerves are there? How many of each type?
31 pairs:
- 8 cervical (C1-C8)
- 12 thoracic (T1-T12)
- 5 lumbar (L1-L5)
- 5 sacral (S1-S5)
- 1 coccygeal (Co)
What do the posterior/dorsal and anterior/ventral ramus innervate?
Posterior/dorsal ramus: innervates the back (epaxial muscles)
Anterior/ventral ramus: innervates most other muscles of the body (hypaxial muscles) except the back and head
Epaxial vs hypaxial muscles
1. Location
2. Innervated by?
Epaxial muscles:
1. Located on the ventral side of the body (i.e. back muscles)
2. Innervated by the ventral ramus
Hypaxial muscles:
1. Located on the dorsal side of the body (i.e. other muscles besides the back muscles)
2. Innervated by the dorsal ramus
Where in the vertebral column does the spinal cord typically end?
Between L1 and L2
Cervical vs thoracic vs lumbar vertebrae:
1. Size/shape of body
2. Size/shape of vertebral foramen
3. Size/shape of spinous process
4. Structure of transverse process
Cervical vertebrae (except C1 atlas and C2 axis):
1. Body: small, square shaped
2. Vertebral foramen: triangular
3. Spinous process: short, bifid
4. Transverse proess: has foramen transversarium
Thoracic vertebrae:
1. Body: medium, heart-shaped
2. Vertebral foramen: circular
3. Spinous process: long, slopes inferiorly
4. Transverse process: has facets for articulation with ribs
Lumbar vertebrae:
1. Body: large, kidney-shaped
2. Vertebral foramen: triangular
3. Spinous process: thick, short
4. Transverse process: no foramen transversarium or facets
Special features of atlas (C1)
- Lacks a vertebral body (fused to body of C2 axis)
- No intervertebral disc between C1 and C2
Where do spinal nerves exit from?
Interveterbral foramina (between the pedicles of adjacent vertebrae)
Label the 5 regions of the vertberal colum:
1. Name
2. Number of vertebrae
- 7 cervical vertebrae (C1-C7)
- 12 thoracic vertebrae (T1-T12)
- 5 lumbar vertebrae (L1-L5)
- 5 sacral (S1-S5, fused to form sacrum)
- 4 coccygeal (Co1-Co5, fused to form coccyx)
Special features of axis (C2)
- Dens
Special features of axis (C2)
- The body of C1 fuses onto the body of C2 to form the dens, which acts as a pivot that allows the atlas and attached head to rotate on the axis
- No intervertebral disc between C1 and C2
What are the 2 major types of joints between vertebrae?
- Symphyses between vertebral bodies (i.e. the intervertebral discs)
- Synovial joints between articular processes (zygapophysial joints)
How many joints does a typical vertebra have with adjacent vertebrae?
6 joints:
- 2 symphyses (one above and below)
- 4 synovial joints (two above and below)
Label the symphesis (joint) present between adjacent vertebral bodies
- Hyaline cartilage
- Intervertebral disc: anulus fibrosus and nucleus pulposus
Compare the features of zygaopophysial joints between articular processes in the cervical vs thoracic vs lumbar region:
1. Orientation
2. What kind of movement does it facilitate/limit?
Cervical region:
1. Slopes inferiorly from anterior to posterior
2. Facilitates flexion and extension
Thoracic region:
1. Oriented vertically
2. Facilitates rotation, limits flexion and extension
Lumbar region:
1. Curved/wrapped
2. Limited range of movement, but flexion and extension are still allowed
Characteristics of anterior and posterior longitudinal ligaments
Anterior longitudinal ligaments:
- Attached along its length to the anterior surface of vertebral bodies and intervertebral discs
- Attached to the base of the skull and anterior surface of the sacrum
Posterior longitudinal ligaments:
- Attached along its length to the posterior surface of vertebral bodies and intervertebral discs
Label the 5 regions of the vertberal colum:
1. Name
2. Number of vertebrae
- 7 cervical vertebrae (C1-C7)
- 12 thoracic vertebrae (T1-T12)
- 5 lumbar vertebrae (L1-L5)
- 5 sacral (S1-S5, fused to form sacrum)
- 4 coccygeal (Co1-Co5, fused to form coccyx)
Special features of axis (C2)
- The body of C1 fuses onto the body of C2 to form the dens, which acts as a pivot that allows the atlas and attached head to rotate on the axis
- No intervertebral disc between C1 and C2
Label the 5 regions of the vertberal colum:
1. Name
2. Number of vertebrae
- 7 cervical vertebrae (C1-C7)
- 12 thoracic vertebrae (T1-T12)
- 5 lumbar vertebrae (L1-L5)
- 5 sacral (S1-S5, fused to form sacrum)
- 4 coccygeal (Co1-Co5, fused to form coccyx)
Special features of axis (C2)
- The body of C1 fuses onto the body of C2 to form the dens, which acts as a pivot that allows the atlas and attached head to rotate on the axis
- No intervertebral disc between C1 and C2
Characteristics of ligamenta flava
- Passes between laminae of adjacent vertebrae
- Runs between the posterior surface of the lamina on the vertebra below to the anterior surface of the lamina of the vertebra above
- Resists separation of the laminae in flexion
Characteristics of supraspinous ligament
- Passes along the tips of spinous processes from CVII (C7) to the sarcum
Characteristics of ligamentum nuchae
- Attached to the skull and the spinous process of CVII (C7)
- Triangular, sheet-like structure in the median saggital plane
- Supports the head and resists flexion
- Provides attachment for adjacent muscles
Label the 5 regions of the vertberal colum:
1. Name
2. Number of vertebrae
- 7 cervical vertebrae (C1-C7)
- 12 thoracic vertebrae (T1-T12)
- 5 lumbar vertebrae (L1-L5)
- 5 sacral (S1-S5, fused to form sacrum)
- 4 coccygeal (Co1-Co5, fused to form coccyx)
Special features of axis (C2)
- The body of C1 fuses onto the body of C2 to form the dens, which acts as a pivot that allows the atlas and attached head to rotate on the axis
- No intervertebral disc between C1 and C2
Characteristics of interspinous ligaments
- Passes between adjacent spinous processes
- Blends with the supraspinous ligament posteriorly and ligamenta flava anteriorly
Label the superficial group of back muscles and state their general function
- Trapezius
- Latissimus dorsi
- Levator scapulae
- Rhomboid major
- Rhomboid minor
Function: moves the scapula and humerus
Label the intermediate group of back muscles and state their general function
- Serratus posterior superior: elevates ribs II to V
- Serratus posterior inferior: depresses ribs IX to XII
What is the structure in green and what is its function?
Thoracolumbar fascia:
Connective tissue that covers the deep muscles of the back and trunk. It is critical to the overall organisation and integrity of the region.
Label the following deep group of back muscles. State their category name and function.
Spinotransversales muscles:
- Splenius capitis (broad)
- Splenius cervicis (narrow)
Function: Draw head backwards, extending the neck, and rotate the head to one side
Label the following deep group of back muscles. State their category name and function.
Erector spinae muscles
(3 verticle columns)
Outer column: Iliocostalis
- Iliocostalis lumborum
- Iliocostalis thoracis
- Iliocostalis cervicis
Middle column: Longissimus
- Longissimus thoracis
- Longissimus cervicis
- Longissimus capitis
Inner column: Spinalis
- Spinalis thoracis
- Spinalis cervicis (not pictured)
- Spinalis capitis (splenius capitis in diagram)
Function: primary extensors of the vertebral column and head
Label the following deep group of back muscles. State their category name and function.
Transversospinales muscles
(3 major groups)
Most superficial:
- Semispinalis thoracis
- Semispinalis cervicis
- Semispinalis capitis
Intermediate:
- Multifudus
Deepest:
- Rotatores lumborum
- Rotatores thoracis
- Rotatores cervicis
Function: extend the vertebral colmn and head, turn/rotate the trunk
Label the following deep group of back muscles. State their category name and function.
Segmental muscles
- Interspinales: stabilises adjoining vetebrae during movements of the vetebral column
- Intertransversarii: stabilises adjoining vetebrae during movements of the vetebral column
- Levatores costarum: elevates ribs (not pictured)
Label the following deep group of back muscles. State their category name and function.
Suboccipital muscles
- Rectus capitis posterior major
- Rectus capitis posterior minor
- Obliquus capitis superior
- Obliquus capitis inferior
Function: extend and rotate the head
These muscles connect C1 and C2, and connect both vetebrae to the base of the skull.
Special features of axis (C2)
- The body of C1 fuses onto the body of C2 to form the dens, which acts as a pivot that allows the atlas and attached head to rotate on the axis
- No intervertebral disc between C1 and C2
Label the 5 regions of the vertberal colum:
1. Name
2. Number of vertebrae
- 7 cervical vertebrae (C1-C7)
- 12 thoracic vertebrae (T1-T12)
- 5 lumbar vertebrae (L1-L5)
- 5 sacral (S1-S5, fused to form sacrum)
- 4 coccygeal (Co1-Co5, fused to form coccyx)
- What muscles make up the suboccipital triangle?
- What structures does the area contain?
- Muscles of the suboccipital triangle:
- Rectus capitis posterior major
- Obliquus capitis superior
- Obliquus capitis inferior - Contents of the suboccipital triangle:
- Posterior ramus of C1
- Vertebral artery
- Veins
Where are the two major swelling/enalrgements in the spinal cord?
- Cervical enlargement: C5 to T1 (spinal nerves innervate upper limbs)
- Lumbosacral enlargement: L1 to S3 (ispinal nerves innervate lower limbs)
Label the arteries of the spinal cord
- Segmental spinal arteries
- Segmental meullary arteries
- Anterior/posterior radicular arteries
- 1 anterior spinal artery
- 2 posterior spinal arteries
Label the veins of the spinal cord
- Anterior/posterior spinal veins
- Internal vertebral plexus
Where does the subarachnoid space end?
Lower border of S2
Label the 3 horns of the gray matter
- Dorsal (posterior) horn
- Ventral (anterior) horn
- Lateral horn
Special features of axis (C2)
- The body of C1 fuses onto the body of C2 to form the dens, which acts as a pivot that allows the atlas and attached head to rotate on the axis
- No intervertebral disc between C1 and C2
Special features of axis (C2)
- The body of C1 fuses onto the body of C2 to form the dens, which acts as a pivot that allows the atlas and attached head to rotate on the axis
- No intervertebral disc between C1 and C2
Where does the subarachnoid space end?
Lower border of S2
Label the 5 regions of the vertberal colum:
1. Name
2. Number of vertebrae
- 7 cervical vertebrae (C1-C7)
- 12 thoracic vertebrae (T1-T12)
- 5 lumbar vertebrae (L1-L5)
- 5 sacral (S1-S5, fused to form sacrum)
- 4 coccygeal (Co1-Co5, fused to form coccyx)
Special features of axis (C2)
- The body of C1 fuses onto the body of C2 to form the dens, which acts as a pivot that allows the atlas and attached head to rotate on the axis
- No intervertebral disc between C1 and C2
What is the space between the arachnoid and pia mater called? What does it contain?
Subarachnoid space: contains cerebrospinal fluid
What kind of neurons do the posterior/dorsal and anterior/ventral roots contain?
Posterior/dorsal root: sensory neurons
Anterior/ventral root: motor neurons
Label this typical spinal nerve
- Dorsal/ventral roots
- Dorsal/ventral rami
- Dorsal root ganglion
- Mixed spinal nerve
What is the function of paravertebral ganglia?
They are connected to the ventral ramus of spinal nerves and are connected to each other, forming a sympathetic chain.
White vs gray ramus communicans:
1. What nerves do they carry?
2. What level of the spinal cord do they exist at?
3. Are they myelinated?
White ramus communicans:
1. Carries preganglionic nerve fibres from the spinal cord to the paravertebral ganglia (entry).
2. Only exists at T1-L2.
3. Myelinated.
Gray ramus communicans:
1. Carries postganglionic nerve fibres from the paravertebral ganglia to their destination (exit).
2. Exists at every level of the spinal cord.
3. Unmyelinated.
Outline the sympathetic pathway
- Lateral horn
- Ventral horn
- Ventral root
- Mixed spinal nerve
- Ventral ramus
- White ramus communicans
- Paravertebral synapse
- Gray ramus communicans
- Ventral ramus
- Hypaxial muscle
or
- Ventral ramus
- Dorsal ramus
- Expaxial muscle
Outline the sympathetic pathway to a region above T1
- Lateral horn
- Ventral horn
- Ventral root
- Mixed spinal nerve
- Ventral ramus
- White ramus communicans
- Paravertebral ganglion (NO synapse here)
- Travel up sympathetic chain (as preganglionic fiber)
- Enter a paravertebral ganglion above T1
- Exit the paracertebral ganglion via gray ramus communics
- Ventral ramus
- Target muscle
Label the 5 regions of the vertberal colum:
1. Name
2. Number of vertebrae
- 7 cervical vertebrae (C1-C7)
- 12 thoracic vertebrae (T1-T12)
- 5 lumbar vertebrae (L1-L5)
- 5 sacral (S1-S5, fused to form sacrum)
- 4 coccygeal (Co1-Co5, fused to form coccyx)
Label the parts of this spinal nerve
- Dorsal/lateral/ventral horns
- Dorsal/ventral roots
- Dorsal root ganglion
- Mixed spinal nerve
- Dorsal/ventral rami
- Gray/white ramus communicans
- Paravertebral ganglion
What is the space between the arachnoid and pia mater called? What does it contain?
Subarachnoid space: contains cerebrospinal fluid
Where does the subarachnoid space end?
Lower border of S2
What kind of neurons do the posterior/dorsal and anterior/ventral roots contain?
Posterior/dorsal root: sensory neurons
Anterior/ventral root: motor neurons
Special features of axis (C2)
- The body of C1 fuses onto the body of C2 to form the dens, which acts as a pivot that allows the atlas and attached head to rotate on the axis
- No intervertebral disc between C1 and C2
What kind of vertebrae are uncovertebral joints present in?
In cervical vertebrae
