CRANIO-VERTEBRAL JOINTS AND SUBOCCIPITAL REGION

OUTLINE

I. CRANIOVERTEBRALJOINTSII. PREVERTEBRAL MUSCLESIII. SUB-OCCIPITAL REGION

Muscles ofback extendto neck

Specialized(Suboccipital) muscles atC1 and C2

Correlates:Hangman's fracturesResearch:Anatomy researchbased on imaging

HEADACHE

WORD OF THE DAY -SUBLUXATION =partial dislocation

BODY

VERTEBRAL ARCH

PEDICLE

TRANSVERSE PROCESS

LAMINA

SPINOUS PROCESS

BODY

ARTICULAR PROCESSES(FACETS)

PARS ARTICULARIS(INTERARTICULARIS)VERTEBRAE: ANATOMICAL,

CLINICAL TERMINOLOGY

PARS ARTICULARIS(INTERARTICULARIS) - IMPRECISE CLINICAL TERM (PARS) - part of a vertebra located between the inferior and superior articular processes of the facet joint (region between the lamina and pedicle).

SUBLUXATION -partial dislocationof vertebral body

BODYDISPLACED

CERVICAL VERTEBRA

ant.

post.

lat.view

NOSE

ARTICULAR FACETS -ANGLED SUPERIORLY AND MEDIALLY

- PERMIT -

1) FLEXION-EXTENSION 2) ROTATION

REVIEW:CERVICALVERTEBRA

MOVEMENTS OF HEAD AND NECK: body language

FLEXION - anterior EXTENSION - posterior

LATERAL FLEXION - head on shoulder, face forward

ROTATION - face turned,look over shoulder

YES

NOMAYBE

FIRST CERVICAL VERTEBRA = C1 (ATLAS)

SECOND CERVICAL VERTEBRA = C2 (AXIS)

DENS

Superior articular facets abut occipital condyles -Joint permits Flexion-Extension "yes" movement of head; Does not permit rotation

Ring of Atlas rotates on Dens of C2- C1-C2 Joint Permits Rotational movement of head "No"; Does not permit flex-extend

SUPERIORARTICULARFACET

1. ANTERIOR LONGITUDINAL LIGAMENT -Strong band on anterior side

C. LIGAMENTS

2. POSTERIOR LONGITUDINAL LIGAMENT-weaker, narrower band

3. LIGAMENTA FLAVA - yellow elastic bands connecting laminae

Review ligaments of back

Ligamenta Flava

Posterior Longitudinal Ligament

Anterior Longitudinal Ligament

LIGAMENTS OF SPINAL COLUMN

NOSE

ORIENT TO BISECTED HEAD

ATLAS C1

AXIS C2

NOSE

ATLAS C1

AXIS C2

ATLAS C1

AP view

Antero-posterior film of with mouth open

1. Transverse process of C22. Ramus of mandible3. Odontoid process (dens) of C2

DENS OFAXIS C2

ATLAS C1

1. ANT. ATLANTO-OCCIPITAL MEMBRANE (C1-OCCIP) = ANT. LONG. LIG.

3. POST.ATLANTO-OCCIPITALMEMBRANE(C1-OCCIP) =LIG.FLAVUM

2. MEMBRANA TECTORIA (C2-OCCIP) = POST. LONG. LIG.

B. LIGAMENTS OF CRANIO-VERTEBRAL JOINTS

Some are extensionsof ligaments of vertebral column

C2 FUNCTIONS:STABILIZE JOINTPROTECT MEDULLAPREVENT EXCESSMOVEMENT

NOSE

Note: Post. Atlanto-occipital membrane and Membrana tectoria fuse to DURA

DENS C1

C2

ORIENT TO VIEW STANDING INSIDE VERTEBRALCANAL LOOKING ANTERIOR

MEMBRANA TECTORIA

POST. LONG. LIG.

4. CRUCIATE (CROSS) LIGAMENT-parts

1) Transverse Ligament of Atlas

2) Superior Band to Occipital Bone

3) Inferior Band to Body of C2

C. LIGAMENTS OF CRANIO-VERTEBRAL JOINTS

INFERIORBAND

SUPERIORBAND

TRANSVERSE LIGAMENT OF ATLAS - attaches to inner side of atlas (C1); Holds Dens (C2) Anteriorly

LIGAMENTS OF CRANIO-VERTEBRAL JOINTS

C1

C2

Henry VIII – Executed 72,000 people

Medulla

F/E= Flex-ExtendR=Rotate

Knot

Joint C1-C2 Only Rotates, No Flex-Ext; All Other Joints Flex-Ext

Knot Post. to C1-C2 Flexes Joint ; Sudden Drop Breaks Vertebrae and Ligaments,Vertebrae can penetrate CNS – Instantaneous death ; Knot anywhere else just flexes neck; Death by strangulation -with prolonged Agony

DEATH BY HANGINGFLEXNECK

F/ER

T1 - MRI - BONES,FLUID DARK

F/EF/EF/EF/E

CT OF HANGMAN'S FRACTURE

AXIS C2

ATLAS C1

FRACTURE

ANATOMICALLY,FRACTURES OCCURWITH FLEXION OR EXTENSION OF C1-C2 JOINT; AUTO WRECKS, FALLS IN ELDERLY MOSTLYHYPEREXTENSION

**

CLASSIFYFRACTURESC2

C2

C1

C3

- Fractures of spine occur in 14% of hospital admissions following automobile accidents (cervical 6%)- Reduction by use of both seat belts and air bagsWang, J. Neurosurg. Spine 10: 86-92, 2009

Alar Ligament

5. Alar “Check”Ligaments -From Dens to Occipital Bone- PreventsExcessive Rotation of Head

C. LIGAMENTS OF CRANIO-VERTEBRAL JOINTS

PrevertebralMuscles -Located anterior to Cervical vertebrae

II. PREVERTEBRAL MUSCLES

Lab Prosections:Disarticulate C1 – occipital bone separate in Retropharyngeal Space

Head, structures of ant. and lat.neck can be displaced forward

PREVERTEBRAL MUSCLES

ACT - FLEX NECK/HEADINN - CERVICAL VENTRAL RAMI

2. Longus capitisO - Trans processes C3-C6I - Occipital bone

1. Longus colliO- Trans processes Lowercervical vertebraeI - Bodies upper cervicalvertebrae

Colli = neck in Latin

4. Rectus Capitis Lateralis O - Atlas (Trans process)I - Occip. Bone

PREVERTEBRAL MUSCLES

3. Rectus Capitis Anterior O - Atlas I - Occip. Bone

TRAPEZIUS

Recall: Dissection Back

SUBOCCIPITAL REGION

SPLENIUS CAPITIS AND SPLENIUS CERVICIS-located deep to trapezius

1. Rectus Capitis Post. MinorC1 to Occipital bone

2. Rectus Capitis Post. MajorC2 to Occipital bone

3. Obliquus Capitis SuperiorC1 to Occipital bone

4. Obliquus Capitis InferiorC2 to C1

Rectus Capitis Post. Minor

Rectus Capitis Post. Major

Obliquus Capitis Superior

Obliquus Capitis Inferior

SUBOCCIPITAL MUSCLES

All innervated by -Suboccipital N. (dorsal ramus C1)

Semi-spinalisreflected

SUBOCCIPITAL MUSCLES - actions deduced from origin/insertion and location

1. Rectus Capitis Posterior Minor-Extend2. Rectus Capitis Posterior Major-Extend/rotate3. Obliquus Capitis Superior-Extend4. Obliquus Capitis Inferior-Rotate

SUBOCCIPITAL TRIANGLE = Rectus Capitis Posterior Major, Obliquus Capitis Inferior, Obliquus Capitis Superior

flex-extend

rotate

OCCIPITALBONE

C1 - ATLAS

C2 - AXIS

Rectus CapitisPosteriorMinor

Rectus CapitisPosteriorMajor

Obliquus CapitisInferior

Obliquus CapitisSuperior

NOTE: OBLIQUUS CAPITIS INFERIOR - PRODUCES ONLYROTATION OF HEAD **

SUBOCCIPITAL TRIANGLE - ARTERIES/NERVES

A. NERVES

1) Suboccipital Nerve- Dorsal ramus C1 -Motor to SuboccipitalMuscles2) Greater Occipital Nerve - Dorsal ramus C2 - Sensory to skin

B. ARTERIES

1) Vertebral Artery2) Occipital Artery

C2

C1

Vertebral A.

Occipital A. Suboccipital Nerve

Greater Occipital Nerve

Bifurcation

CommonCarotidArtery

VertebralArtery

InternalCarotidArtery

External Carotid Artery

Lingual Artery

Facial Artery

Maxillary Artery

Occipital Artery

Left side onlyHighMag

VERTEBRALARTERYTURNS ABOVE C1

I

II

III

IVV

VIVII+VIII

IX, X+XI XII

V1V2V3

PITUITARYSTALK INTERNAL CAROTID A.

VERTEBRAL A.

MIDDLE MENINGEAL A.

SEE VERTEBRALARTERY INSIDECRANIAL CAVITY

ANATOMY OF HEADACHE - Headache = pain in any region of the head- Complex because diverse causes: ex. vascular, meningeal, muscular- Structures sensitive to pain: scalp, air sinuses, meninges, arteries and veins- Neural tissue is Insensitive: brain parenchyma (nerve cells, glia; except small part of midbrain)

Sensory Innervation of Dura: from recurrent branches of nerves that enter cranial cavity

- Trigeminal: branches of V1, V2 and V3 (ex. nervous spinosus);- Also: (Vagus X), Upper cervical spinal nerves

V1

V2

V3 branchesex.NervusSpinosus

Sensory branchesof C1 and C2,Vagus (X)

SENSORY INNERVATION OF DURA

TENSION HEADACHE: POSSIBLE ROLE OF SUBOCCIPITAL MUSCLES

DETECT HEAD ROTATION:MUSCLE SPINDLES IN SUBOCCIPITAL MUSCLES

Can contribute to reflexes

ANATOMICAL RESEARCH LIVES!

Rectus Capitis Post. Minor Inserts to Post. Atlanto-Occipital membrane and Dura

RectusCapitisPost minor

Dura

Post. Atlanto-Occip. Membrane = LIG. FLAVA

Cranial dura is innervated; possible cause of headache

OCCIP.BONE

C1

RECTUS CAPITIS POSTERIOR MINOR ATTACHES TO DURA