PHARYNX, CRANIO- VERTEBRAL JOINTS, AND PREVERTEBRAL REGION 2009 DENTAL & OPTOMETRY STUDENTS -George Salter, Ph.D

is a 15 cm. long tube connecting inferiorly with the oesophagus is a 15 cm. long tube connecting inferiorly with the oesophagus. It is 5 cm. wide superiorly, and it is only 1.5 cm wide as it merges with the oesophagus. This point is the most narrow diameter of the GI tract. PHARYNX: PHARYNX ESOPHAGUS

SUBDIVISIONS OF PHARYNX

Nasopharynx Oropharynx Laryngopharynx

Nasal Cavity Nasopharynx Oral Cavity Oropharynx Laryngo- pharynx or Hypopharynx Laryngeal Cavity

in the form of four layers WALLS OF PHARYNX- in the form of four layers Mucous membrane-including “tonsil” Pharyngobasilar fascia = Submucosa Muscle layer Buccopharyngeal fascia

Cross Section, (Oral Pharynx) for example: Mucosa; Submucosa or Pharyngobasilar Fascia (including the palatine tonsil); (3) Muscular; and (4)Buccopharyngeal Fascia

PHARYNX IN POSTERIOR VIEW Submucosa extended superiorly as the pharyngobasilar fascia Use scissors in lab

ANTERIOR RELATIONSHIPS Nasal cavity Oral cavity Laryngeal cavity

Choanae Soft Palate & Uvula Aditus

CHARACTERISTICS OF EACH OF THE THREE PARTS OF THE PHARYNX

(1) NASOPHARYNX (MUCOSA INTACT) Pharyngeal tonsil Auditory tube orifice Choana Pharyngeal recess Torus tubarius Salpingopharyngeal fold Uvula Pharyngeal isthmus

NASOPHARYNX – with mucosa removed Torus Tubarius Tensor (veli) palatini Levator (veli) palatini Salpingopharyngeus

Torus Tubarius Naso- pharynx Middle Ear Pharyngo- Tympanic Tube

SOFT PALATE --comprised of glands & muscle & separates nasopharynx from oral pharynx Uvula

(2) OROPHARYNX (MUCOSA INTACT) Pharyngeal Isthmus Palato- glossal fold Palato- pharyn-geal fold Palatine Tonsil Bed

TONSILLAR BED I-with mucosa removed Palatoglossus Pharyngobasilar Fascia - Palatopharyngeus Area between the 2 muscles or folds is the throat or fauces.

TONSILLAR BED (WITH MUCOSA & SUBMUCOSA REMOVED) Palatoglossus Superior Constrictor (forming the bed) Palatopharyngeus

? TONSILLAR BED- II Tonsillar br. of facial a. External palatine Superior constrictor with inferior part re- moved Tonsillar br. of facial a. External palatine (paratonsillar) v. ? Glossopharyngeal n. (IX) Middle constrictor

A notable relationship: Styloglossus—lying lateral to superior constrictor & joining with hyoglossus

Hard palate Uvula Soft palate

(3)Laryngopharynx (with mucosa intact) Aryepiglottic fold- forming part of the aditus Piriform recess-with mucosal fold indicating the location of the internal laryngeal n. Indicates aditus or opening to larynx Bulge indicating location of cricoid cartilage

MUSCLES OF PHARYNX

Outer Layer (circular)- constrictors-3 Inner Layer (longitudinal)-3 (1) (1) (2) (2) (3) (3) Now, let’s blow these longitudinal muscles up

Inner, Longitudinal Mm (3): (1) Salpingopharyngeus (2) Palatopharyngeus (3) Stylopharyngeus – in reality only its in- ferior fibers are shown

Outer, Circular Ms.-3 (1) Superior Constrictor (2) Middle Constrictor (3) Inferior Constrictor

Inner Longitudinal Muscle Layer Outer Circular Muscular Layer (3) (3) Salpingo- pharyngeus Superior Constrictor Palato- pharyngeus Middle Constrictor Stylo- Pharyngeus (inferior fibers) Inferior Constrictor

Three Constrictor Muscles: Insertions:

Constrictor Muscles Insertion(s)-all insert posteriorly Pharyngeal tubercle Midline Raphe Origins of constrictors- next:

Origins of the three constrictor muscles (all arise anteriorly): Superior constrictor Pterygomandibular raphe & bone at either end Middle constrictor Stylohyoid ligament, body & lesser horn of hyoid bone Inferior constrictor Thyroid and cricoid cartilages Esophagus

GAPS ABOVE, BETWEEN,& BELOW CONSTRICTORS: Superior constrictor Middle constrictor Inferior constrictor Esophagus

Gap superior to Sup. Const. Gap between Sup. & Inf. Const. Gap between Middle & Inferior Constrictor Gap inferior to Inferior Constrictor

Structures related to the gaps Pharyngobasilar Fascia pierced by Levator palati m. & Auditory Tube Stylopharyngeus, Stylo- hyoid Ligament & IX N. Thyrohyoid Membrane pierced by the ____ ? Region of Killian’s Dehiscence Recurrent Laryngeal N

NERVES OF PHARYNX

Afferent Fibers From Pharynx: Red (Crimson)= V2- naso-pharyngeal n. Blue = IX n.—pharyngeal brs. Auburn = X n.-internal laryngeal brs.

Motor Innervation of Pharynx And Pharyngeal Plexus Br. Of IX to Stylopharyn- geus (SVE) Pharyngeal brs. of X (SVE) --disruption of these fibers leads to dysphagia Add these sensory fibers and the to- tal equals the pharyngeal plexus Pharyngeal brs. of sympathetic tr. (GVE)

BLOOD SUPPLY & LYMPHATICS

Ascending palatine br. of facial artery S A L F O P S M Ascending palatine br. of facial artery A=Ascending Pharyngeal A. Pos

Retropharyngeal Lymph Nodes Drain to Deep Cervical Lymph Nodes

PALATINE TONSIL

Jugulodigastric or Tonsillar Node

ATLANTO-OCCIPITAL & ATLANTO-AXIAL JTS.

Atlanto-occipital Joints (Ellipsoid) Atlas and Axis (superior view) C1-C4 Vertebrae Dens Facet for occipital condyle C1 C2 Facet for transverse ligament C3 1. The joints between the sup. articular facets of the atlas and the occipital condyles are the ATLANTOOCCIPITAL (AO) JOINTS. Together the two joints act as an ELLIPSOID JOINT. They permit flexion and extension of the head, as well as lateral flexion (bending to the side). There are three ATLANTOAXIAL (AA) JOINTS. The TWO LAT. AA JOINTS are between the inf. articular facets of the atlas and the sup. articular facets of the axis. These are GLIDING JOINTS. The MEDIAN AA JOINT is a PIVOT JOINT. It is formed by the articulation between the dens and the ant. arch of the atlas, and between the dens and the transverse lig. of the atlas . When one rotates the head from side to side (eg, shaking the head "no"), the skull + atlas rotate together around a central stationary pivot --- the dens. C4 Atlanto-occipital Joints (Ellipsoid) Allow flexion/extension of head (nodding “yes”) Allow lateral flexion of head Lateral atlanto-axial joints (gliding) Median atlanto-axial joint (pivot)- (shaking “No”)

MUSCLES PRODUCING MOVEMENT OF THE ATLANTO-OCCIPITAL (AO) JOINTS 1. Bilateral action of the longus capitis, rectus capitis anterior, anterior fibers of SCM, and suprahyoid and infrahyoid mm. produce flexion of the AO joints.

MUSCLES PRODUCING MOVEMENT OF THE ATLANTO-OCCIPITAL (AO) JOINTS 1. Bilateral action of the rectus capitis posterior major and minor, superior oblique of head, trapezius (and others) all produce extension of the AO joints. 2. Lateral flexion of the AO joints (not shown) is produced by the unilateral action of the rectus capitis lateralis, superior oblique of head, SCM (and others).

Posterior longitudinal ligament Tectorial membrane Posterior longitudinal ligament Alar ligaments 1. The POST. LONGITUDINAL LIG. runs along the post. surfaces of the vertebral bodies within the vertebral canal. Its upward continuation (above the axis) is the TECTORIAL MEMBRANE. Deep to the tectorial membrane are some imp. ligaments related to the median AA joint. The thick TRANSVERSE LIG. OF THE ATLAS holds the dens against the ant. arch of the atlas. The SUP. & INF. LONGITUDINAL FIBERS pass to the ant. margin of the f. magnum and the body of the axis (resp.). The transverse lig. + the sup. and inf. longitudinal fibers form the CRUCIFORM LIG. The strong ALAR LIGS. pass superolaterally from the dens to the med. aspects of the occipital condyles. Superior longitudinal band CRUCIATE LIGAMENT Transverse ligament of atlas Inferior longitudinal band

HYPEREXTENSION OF THE HEAD ON THE NECK FRACTURE OF THE AXIS (HANGMAN’S FRACTURE) 1. With the knot placed beneath the chin, hyperextension of the head on the neck occurs when the body drops suddenly through the gallows floor. 2. The resulting fracture of the axis is called a hangman’s fracture. 3. Note that the pars interarticularis (between the superior and inferior articular processes) of the axis is fractured. Pars inter- articularis

ORIGINALLY, THERE WERE 8 CERVICAL SYMPATHETIC GANGLIA, ONE ASSOCIATED WITH EACH CERVICAL SPINAL NERVE. BUT, THESE GANGLIA COALESCED INTO 3 (4) GANGLIA. THEREFORE, THESE REMAINING CERVICAL SYMPATHETIC GANGLIA WERE LEFT TO SEND POSTSYNAPTIC FIBERS (VIA GRC) TO SEVERAL SPINAL NERVES EACH.

I. Carotid n postgang. fibers The sympathetic trunk is located posterior to the carotid sheath on the prevertebral fascia Superior Cervical Ganglion (upper 4 ganglia) Ext. Carotid N. internal carotid a hyoid Middle cervical ganglion (ganglia 5 & 6) Superior cervical ganglion – found at the levels of C2&3 vertebrae Middle cervical ganglion – found at C6 vertebra Inferior cervical ganglion – found between the base of the TP of C7 vertebra & neck of the 1st rib Inferior cervical ganglion (ganglia 7 & 8) R. Common Carotid A 1st rib (cut) R. subclavian a. (cut) K. Kryger

Overview of Sympathetics to Head Postganglionic axons distributed via Ext. & Int. carotid ns.( carotid plexus) Target tissue smooth muscle in vessel walls, dilator pupillae m, & sweat glands. superior cervical ganglion (in neck) Preganglionic axons ascend in the sympathetic trunk Functions: 1) vasoconstriction 2) dilate pupils 3) stimulate sweat glands Preganglionic fibres enter the sympathetic trunk Lateral horns of cord levels T1-2 K. Kryger

NOW, LET’S CONSIDER SYMPATHETIC FIBERS TO THE CERVICAL VISCERA

Sympathetic fibers to the neck viscera, eg Sympathetic fibers to the neck viscera, eg. the pharynx, would ascend as presynaptic fibers to reach the cervical sympathetic ganglia. Synapse would then occur, and postsynaptic fibers would pass to the viscera via direct branches or via the blood vessels.

Cervical Viscera Origin T1-L2

LAB

1. REMOVE ALL MUSCULATURE FROM OCCIPITAL BONE & POSTERIOR ARCH OF ATLAS.

2. REMOVE WEDGE OF OCCIPITAL BONE

REMOVE POST. ARCH OF ATLAS, TRANSECT & REMOVE CERVICAL SPINAL CORD & ASSOCIATED MENINGES

4. CUT & REFLECT TECTORIAL MEMBRANE INFERIORLY. 5. CUT ALAR LIGS. & SUP. LONGITUDINAL BAND. 6. DISARTICULATE AO JOINTS (Indicated by the vertebral artery ) W/ HAMMER & CHISEL. Tectorial membrane Tectorial Membrane Posterior longitudinal ligament Alar ligaments 1. The POST. LONGITUDINAL LIG. runs along the post. surfaces of the vertebral bodies within the vertebral canal. Its upward continuation (above the axis) is the TECTORIAL MEMBRANE. Deep to the tectorial membrane are some imp. ligaments related to the median AA joint. The thick TRANSVERSE LIG. OF THE ATLAS holds the dens against the ant. arch of the atlas. The SUP. & INF. LONGITUDINAL FIBERS pass to the ant. margin of the f. magnum and the body of the axis (resp.). The transverse lig. + the sup. and inf. longitudinal fibers form the CRUCIFORM LIG. The strong ALAR LIGS. pass superolaterally from the dens to the med. aspects of the occipital condyles. Superior longitudinal band CRUCIATE LIGAMENT Transverse ligament of atlas Inferior longitudinal band

7. WORK YOUR HANDS INTO RETROPHARYNGEAL SPACE, AND PULL CERVICAL VISCERA AND HEAD FORWARD AWAY FROM VERTEBRAL COLUMN.

??? 8. Cut prevertebral muscle attachment into the capitus Rectus capitis lateralis ???

HAPPY TRAILS TO YOU….

Lymph drainage review Superficial cervical Nodes of head & face – in the shape of a collar (red line) around head and located in relationship to E.J.V. in Neck Superficial Cervical Nodes Deep Cervical Nodes – located in relation- ship to the I.J.V. Division of deep cervical nodes into superior & inferior groups by omo- hyoid tendon

AXIS (C2): POSTEROSUPERIOR VIEW Dens Facet for dens Tubercle for transverse lig. Sup. facet for occipital condyle Axis-Anterior view Groove for vertebral a. ATLAS (C1): SUPERIOR VIEW Post. facet for transverse lig. Post. tubercle Post. arch Sup. facet for atlas 1. Atlas: a. Atlas is essentially a ring of bone, consisting of two lateral masses connected by ant. and post. arches. b. Transverse processes project further laterally than other cervical vertebrae (giving mechanical advantage to muscles that attach to it (eg., inf. oblique). Transverse foramen for passage of vertebral a. c. Ant. tubercle is for attachment of ant. longitudinal lig. and upper end of longus colli m. d. Atlas has no spine, just a post. tubercle on post. arch. e. Post. arch has groove for vertebral a. f. Lateral masses have concave, kidney-shaped facets superiorly for reception of the occipital condyles. g. Each lateral mass also has a tubercle for attachment of the transverse ligament of the atlas which runs from one lateral mass to the other. h. Anterior arch has a facet on its posterior aspect for articulation w/ the dens. 2. Axis a. Strongest of cervical vetebrae. b. Has two large, flat bearing surfaces, superior articular facets, for articulation w/the atlas above. c. Dens (odontoid process) represents body of atlas and projects superiorly to articulate with the ant. arch of the atlas. Dens also has a facet on its posterior aspect for the transverse lig. of the atlas. d. Spinous process of axis is large and bifid. Interarticular part Lat. Proc. Ant. arch Ant. tubercle Inf. articular pr. Spinous pr. Atlas-Inferior View AXIS (C2): POSTEROSUPERIOR VIEW