Anatomy: Vertebral Column, Muscles of the Back, & Suboccipital Region

What is this curvature?

Kyphosis

What is this curvature?

Lordosis

What is this curvature?

Scoliosis

What is the most common group for kyphosis? Why?

Older women due to lower levels of estrogen leading to decreased bone density

What is the most common group for lordosis? Why?

Pregnant or overweight people, as it pulls on the lower abdomen, causing increased pressure on the lumbar spine

Formed by the L and R pedicles and lamina

Arch

Combine to form vertebral canal which contains the spinal cord, meninges, fat, spinal nerve root, and vessels

Vertebral foramen

Regional characteristics of cervical vertebrae

• body is small and wide

• large, triangular foramen

• short transverse processes

• atypical C1, C2, & C7

Regional characteristics of thoracic vertebrae

• body: heart shaped, costal facets

• small, circular foramen

• long, sloping spinous processes

• articulate with ribs

Regional characteristics of lumbar vertebrae

• large, kidney shaped body

• large, triangular foramen

• short, thick spinous processes

Where are intervertebral discs found?

Between the articulating surfaces of the vertebral bodies

What are the functions of the intervertebral discs?

Strong attachments, permit movements, resist deformity, and serve as shock absorbers

Outer concentric ring of fibrocartilage insert obliquely into the epiphysial rims

anulus fibros

Central core of semisolid proteoglycans that are compressed and stretched during movement

Nucleus pulposus

T/F: intervertebral discs are avascular

True

What is the name of this joint?

Uncovertebral joint or Joints of Luschka

Where are the uncovertebral joints located?

C3 to C6

What type of joint are uncovertebral joints?

synovial joints, but can be classified as degenerative spaces

Where is the anterior longitudinal ligament located?

From the pelvic surface of the sacrum to the anterior tubercle of C1 and the occipital bone, anterior to the foramen magnum

What is the purpose of the anterior longitudinal ligament?

Stability of the IV joints and limits extension of the vertebral column (helps to over extension/whiplash)

Where is the posterior longitudinal ligament located?

Within the canal on the posterior aspect of the bodies

What is the purpose of the posterior longitudinal ligament?

Prevents hyperflexion and posterior intervertebral disc herniation (holds disc in)

Which longitudinal ligament is highly sensitive to pain due to being well innervated with pain nerve endings?

Posterior longitudinal ligament

Why is the longitudinal ligament narrower and weaker?

to allow more flexion of the spine (bending forward)

Bony projections that form synovial zygapophyseal (facet) joints with the vertebrae above and below

superior and inferior articular facets

What types of joints are zygapophyseal (facet) joints?

synovial joints

What are the joints of the vertebral joints?

Zygapophyseal (facet) joints

Where is the pars interarticularis?

Region of the vertebra between the superior and inferior articular facets and the pedicle and lamina

Allow gliding movements between the articular processes, but can show anterior/posterior sliding, which can be painful due to pushing on nerves

Zygapophyseal (facet) joints

Where is the ligamentum flava?

Broad, yellow elastic fibrous tissue extending from the lamina above to the lamina below

What does the ligamentum flava do?

Resists separation of the vertebral column at the laminae

Where are the interspinous ligaments?

Thin, weak membrane connecting ALL adjacent spinous processes

Where are the supraspinous ligaments?

Strong, fibrous ligament connecting the adjacent spinous processes from C7 to the lumbar region

Where is the nuchal ligament?

from the external occipital protuberance and posterior border of the foramen magnum to the spinous processes of the cervical vertebrae (median ligament of neck)

Where is the Atlantooccipital Joint?

between lateral masses of C1 and occipital condyles

What are the principle movements of the Atlantooccipital Joint?

flexion and extension (yes movement)

Trapezius: Innervation? Action?

I: spinal accessory nerve

A: elevates, depresses, and retracts scapula; rotates gleniod superiorly

Latissimus dorsi: Innervation? Action?

I: throracodorsal nerve

A: extends, adducts, and medially rotates shoulder joint

Levator scapulae: Innervation? Action?

I: dorsal scapular and cervical spinal nerves

A: elevates scapula & rotates glenoid cavity inferiorly

Rhomboid major and minor: Innervation? Action?

I: dorsal scapular nerve

A: retracts scapula and rotates glenoid cavity inferiorly

Splenius: Innervation? Action?

I: posterior rami of spinal nerves

A: laterally flex the neck and rotate the head; extend the head and neck

Erector spinae (ILS): Innervation? Action?

I: posterior rami of spinal nerves

A: extend vertebral column and head; laterally flex vertebral column

Semispinalis: Innervation? Action?

I: posterior rami of spinal nerves

A: extend head and thoracic & cervical regions

Multifidus: Innervation? Action?

I: posterior rami of spinal nerves

A: stabilizes vertebrae

Rotatores: Innervation? Action?

I: posterior rami of spinal nerves

A: stabilize vertebrae: local extension and rotatory movements

Interspinales: Innervation? Action?

I: posterior rami of spinal nerves

A: extension and rotation of vertebral column

Intertransversarii: Innervation? Action?

I: posterior and anterior rami of spinal nerves

A: lateral flexion of vertebral column

Levatores costarum: Innervation? Action?

I: posterior rami of C8-T11 spinal nerves

A: elevate ribs, assist with respiration

Thoracolumbar fascia function and location

F: muscle attachment and support

L: lower thoracic and lumbar region

Major function of the Erector spinae muscle group

extensor of the vertebral column

What does the triangular area at the most superior part of the back of the neck allow for?

head movement

Suboccipital triangle: muscle at the superomedial boudnary

rectus captis posterior major

Suboccipital triangle: muscle at the superolateral boundary

obliquus capitis superior

Suboccipital triangle: muscle at the inferolateral boundary

obliquus capitis inferior

Suboccipital triangle: muscle at the most medial point

rectus capitis posterior minor

suboccipital nerve is known as

posterior ramus of C1 spinal nerve

Where does the first spinal (suboccipital) nerve emerge?

from the vertebral canal between the atlas and the vertebral artery

What are the 3 articulations of the atlantocaxial joint?

1 median antlantoaxial joint and 2 lateral atlantoaxial joints

What kind of joint is the atlantoaxial joint?

pivot joint

/What is the primary movement altlantoaxial joint?

rotation from L to R; “no” pattern

What nerve innervates the atlantoaxial joint?

C1 spinal nerve

What is the transverse ligament of the atlas?

ligament between the tubercles on the medial aspects of the lateral masses of C1

Purpose of the alar ligament

prevent excessive rotation

The ligaments that make up the cruciate ligaments

• transverse ligament of the atlas

• longitudinal bands

• alar ligament

• tectorial membrane

Vessels that supply all regions of the vertebral column

Periosteal and equatorial branches

Forms the venous plexuses along the vertebral column both inside and outside

spinal veins

Spina bifida

congenital malformation; defect in the closure of the vertebral arch

C1 fractures

• result of vertical force

• can also rupture transverse ligaments, making spinal cord injury more likely

C2 fractures

• high force injury

• “hangman’s fracture”

• severe neck pain due to the C1 nerve

hyperextension (whiplash) injury

• over stretched or torn anterior longitudinal ligament

• can cause fracture and dislocation of vertebrae

spinal stenosis

narrowing of the vertebral foramen that causes compression of the spinal nerve roots

IV disc herniation: what is pushed out? what is compressed?

• herniation of the nucleus pulposus

• compressed spinal nerve root

How many of each type of spinal nerves?

• 8 cervical

• 12 thoracic

• 5 lumbar

• 5 sacral

• 1 coccygeal

Where does the spinal cord start?

medulla oblongata

What is the conus medularis?

the tapering end of the spinal cord

What is the cauda equina?

bundle of nerves spinal nerve roots, inferior to the spinal cord

spinal nerves: posterior (dorsal) roots

• afferent (sensory) fibers

• sensory info from receptors to the CNS

• cell bodies in the spinal ganglia

Spinal nerves: anterior (ventral) roots

• efferent (motor) fibers

• from CNS to skeletal muscles/glands

• cells bodies are in anterior grey horn

What are meninges?

coverings of the spinal cord and brain

What are the 3 types of mater?

• dura mater: tough, external layer

• arachnoid: thin, intermediate layer

• pia: delicate/vascular, innermost layer

Cerebrospinal fluid: what is it? function?

• clear liquid in the subarachnoid space

• cushioning and nutrient to the brain and spinal cord

Where is the needle inserted in a lumbar spinal puncture?

subarachnoid space between the L3-4 or L4-5

Purpose of epidural anesthesia

block sensation inferior the the level of block