The Pharynx
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The Pharynx. Wide muscular tube situated behind nose, mouth & larynx . Upper part transmits air only . Lower part transmits food only . Middle part transmits food & air (only one at a time). The Pharynx. Wide muscular tube situated behind nose, mouth & larynx Upper part transmits air only

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Wide muscular tube situated behind nose mouth larynx upper part transmits air only

The Pharynx

  • Wide muscular tube situated behind nose, mouth & larynx.

  • Upper part transmits air only.

  • Lower part transmits food only.

  • Middle part transmits food & air (only one at a time).


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

The Pharynx

  • Wide muscular tube situated behind nose, mouth & larynx

  • Upper part transmits air only

  • Lower part transmits food only

  • Middle part transmits food & air (only one at a time)


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

The Pharynx

  • Muscular tube lying behind the nose, oral cavity & larynx

  • Extends from the base of the skull to level of the 6th cervical vertebra, where it is continuous with the esophagus

  • The anterior wall is deficient and shows (from above downward):

    • Posterior nasal apertures

    • Opening of the oral cavity

    • Laryngeal inlet


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

The PharyngealWall

  • It is a musculo-membranous wall, composed of:

    • Mucosa & submucosa

    • Pharyngobasilar fascia

    • Muscles: circular & longitudinal

    • Buccopharyngeal fascia

  • The buccopharyngeal fascia is separated from the prevertebral fascia by the retropharyngeal space.


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

The PharyngealWall


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

The Pharyngeal Facia

Bacterial Infection all the way into the abdomen

Alar Fascia

1

1 -- Retropharyngeal Space

Between Buccopharyngeal and Alar Fascia

Buccopharyngeal Fascia

Esophagus

2 -- Danger Zone

Between Alar and Prevertebral Fascia

Trachea

Prevertebral Layer

2

Pretracheal fascia

includes alar and

buccopharyngeal

Pericardium


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

The Pharynx

Important Landmarks

Nasal Cavity

Nasopharynx

  • Soft Palate

  • Epiglottis

  • Cricoid Cartilage

Hard palate

1

Oral Cavity

Oropharynx

2

Larygopharynx

3

Larynx

Trachea


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Pharynx

Nasopharynx

Laryngopharynx

Choanae

Pharyngeal isthmus

Oropharynx

Faucial isthmus

Epiglottis

Eosophagus

Trachea

Larynx


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

SYSTEMA RESPIRATORIUM

Nasal Part

  • Boundaries:

  • Roof:Body of sphenoid & basal part of the occipital bone.

  • Floor:Upper surface of soft palate & the pharyngeal isthmus (opening between the free margin of soft palate and posterior pharyngeal wall)


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

SYSTEMA RESPIRATORIUM

Nasal Part

FUNCTIONS

  • Respiratory- no food ever enters it.

  • Walls are rigid & non-collapsible so air passage is kept patent.

  • Lined by ciliated columnar epithelium

  • Mucus membrane supplied by trigeminal nerve.


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

SYSTEMA RESPIRATORIUM

Nasal Part

  • Nasopharynx

  • Choanae and pharyngeal isthmus

  • Pharyngeal ostium of the auditory

  • tube

  • Auditory tube = salpinx = Eustachian

  • tube

  • Torus levatorius

  • Torus tubarius

C2


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Nasal Part

  • Nasopharynx

  • Choanae and pharyngeal isthmus

  • Pharyngeal ostium of the auditory

  • tube

  • Auditory tube = salpinx = Eustachian

  • tube

  • Torus levatorius

  • Torus tubarius

C2


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Nasal Part

  • Tubal tonsil (Gerlach’s tonsil)

  • Salpingopalatine fold

  • Salpingopharyngeal fold

  • Pharyngeal recess

  • (Rosenmüller‘s fossa)

  • Fornix

  • Pharyngeal tonsil (adenoids)

C2


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Nasal Part

  • Tubal tonsil (Gerlach’s tonsil)

  • Salpingopalatine fold

  • Salpingopharyngeal fold

  • Pharyngeal recess

  • (Rosenmüller‘s fossa)

  • Fornix

  • Pharyngeal tonsil (adenoids)

C2


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Nasal Part

NASOPHARYNX

Sensory CN V2

Torus tubarius

Muscles of Soft Palate

1 - Levator veli palatini – CN X

2 - Muscularis uvulae – CN X

3 -Tensor veli palatini – CN V3

1

3

1

Trigeminal / Semilunar ganglion

2

Tensor – mandibular n.

2

1

Muscles of Pharynx

1 – Salpingopharyngeus – CN X

2 – Palatopharyngeus – CN X

2

Pterygoid hamulus of the Medial Pterygoid Plate


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

SYSTEMA RESPIRATORIUM

Oral Part

  • Lies behind the mouth

  • Extends from soft palate to upper border of epiglottis

  • Boundaries:

    • Roof: soft palate and pharyngeal isthmus

    • Floor: posterior one third of tongue, median & lateral glossoepiglottic folds, and the valleculae


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

SYSTEMA RESPIRATORIUM

Oral Part

  • Middle part situated behind oral cavity.

  • Walls made of superior, middle, inferior constrictors.

  • Communications

  • Above : nasopharynx via pharyngeal isthmus

  • In front: oropharynx via oropharyngeal isthmus

  • Behind: Supported by C2 + C3 vertebrae

  • Lateral wall: Palatine tonsil lying in tonsillarfossa(bounded by palatoglossal & palatopharyngeal arches)


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Oral Part

  • Oropharynx:

  • Soft palate–hyoid bone

  • Fauces (throat)

  • Faucial isthmus

  • Palatoglossal arch

  • Palatopharyngeal arch

  • Tonsillar fossa

  • Palatine tonsil

  • Semilunar fold

  • Supratonsillar fossa

C2

C3


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Oral Part

OROPHARYNX

Sensory – CN IX

Vallecula

Palatopharyngeus m. CN X

Palatine Tonsils

Palatoglossus m. CN X

Named were it inserts

Gag Reflex

Afferent CN IX

Efferent CN X


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Waldeyer’s Ring


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Waldeyer’s Ring


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Laryngeal Part

Lowest part situated behind larynx

  • Extends from upper border of epiglottis to lower border of cricoid cartilage

  • ANTERIOR WALL

  • Inlet of larynx

  • Cricoid & arytenoid cartilages

  • POSTERIOR WALL

  • C3-6 vertebrae

  • LATERAL WALL

  • Has a depression- piriform fossa


Clinical notes

Clinical Notes


Clinical notes1

Clinical Notes

  • Adenoides (enlarged pharyngeal tonsils) & adenoidectomy. Adenoids results in obstruction to nasal breathing and make mouth breathing necessary. The patient develops a typical facial expression called the ‘adenoid facies’. May also cause impaired hearing

  • Otitis media (middle ear infection), secondary to infection of nasopharynx

  • Tonsillitis & Tonsillectomy

Adenoid facies


Clinical notes2

Clinical Notes

  • Peritonsillarabcess: complication of tonsillitis and consists of a collection of pus beside the tonsil (peritonsillar space).

  • Piriformfossa: a common site for the lodging of foreign bodies

  • Pharyngeal pouch:posteromedialherniation of mucosal diverticulum between thyropharyngeal and cricopharyngeal parts of the inferior constrictor muscle leading to dysphagia (difficulty in swallowing) . It occurs mainly in older people

  • Retropharyngeal abcess: may spread to the superior mediastinum


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Muscles of Pharynx

3 CONSTRICTORS

Superior

Middle

Inferior

3 LONGITUDINAL MUSCLES

Stylopharyngeus

Salpingopharyngeus

Palatopharyngeus


Circular constrictor muscles

Circular (Constrictor) Muscles

  • Three in number: Superior, Middle & Inferior

  • Extend around the pharynx and are inserted posteriorly into a fibrous raphe that extends from the pharyngeal tubercle on the occipital bone to the esophagus

  • The three muscles overlap each other

  • The gap between the superior border of the superior constrictor and the occipital bone is filled by thickened pharyngobasilar fascia


Circular constrictor muscles1

Circular (Constrictor) Muscles


Circular constrictor muscles2

Circular (Constrictor) Muscles

  • Superior constrictor

    • Origin: medial pterygoid plate, pterygoidhamulus, pterygomandibular ligament, mylohyoid line

    • Insertion: pharyngeal tubercle, pharyngeal raphe

  • Middle constrictor

    • Origin: lower part of stylohyoid ligament, greater & lesser cornu of hyoid bone

    • Insertion: pharyngeal raphe


Circular constrictor muscles3

Circular (Constrictor) Muscles

  • Inferior constrictor

    • Origin: lamina of thyroid cartilage, cricoid cartilage

    • Insertion: pharyngeal raphe

  • Functions:

  • The constrictor muscles propel the bolus of food down into the esophagus

  • Cricopharyngeus(lower fibers of the inferior constrictor) act as a sphincter, preventing the entry of air into the esophagus between the acts of swallowing


Longitudinal muscles

Longitudinal Muscles

  • Three in number:

    • Stylopharyngeus

    • Salpingopharyngeus

    • Palatpharyngeous

  • Function:

    • Elevate the larynx & pharynx during swallowing


Longitudinal muscles1

Longitudinal Muscles

  • Stylopharyngeus

    • Origin:styloid process

    • Insertion:posterior border of thyroid cartilage

  • Salpingopharyngeus

    • Origin:auditory tube

    • Insertion: blends with palatoglossus

  • Palatopharyngeus

    • Origin:palatine aponeurosis

    • Insertion:posterior border of thyroid cartilage


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Muscles of Pharynx


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Nerve Supply to Pharynx

  • Sensory Nerve Supply:

    • Nasopharynx: Maxillary nerve

    • Oropharynx: Glossopharyngeal nerve

    • Laryngopharynx:Internal laryngeal branch of the vagus nerve

  • Motor Nerve Supply:

    • All the muscles of pharynx, except the stylopharyngeus, supplied by the pharyngeal plexus

    • The stylopharyngeus is supplied by the glossopharyngeal nerve


Blood supply lymphatics

Blood Supply & Lymphatics

  • Arterial supply is derived from branches of:

    • Ascending pharyngeal artery

    • Ascending palatine artery

    • Facial artery

    • Maxillary artery

    • Lingual artery


Blood supply lymphatics1

Blood Supply & Lymphatics

  • Arterial supply is derived from branches of:

    • Ascending pharyngeal artery

    • Ascending palatine artery

    • Facial artery

    • Maxillary artery

    • Lingual artery


Blood supply lymphatics2

Blood Supply & Lymphatics

  • Branches from:

  • External carotid artery

  • Facial artery

  • Lingual artery

  • Branches of maxillary artery


Blood supply lymphatics3

Blood Supply & Lymphatics

  • Venous supply

    The veins drain into pharyngeal venous plexus, which drains into the internal jugular vein


Blood supply lymphatics4

Blood Supply & Lymphatics

VENOUS DRAINAGE

Plexus on posterolateral aspect of pharynx

Drain into IJV & facial vein


Blood supply lymphatics5

Blood Supply & Lymphatics

  • The lymphatics drain into the deep cervical lymph nodes either directly, or indirectly via the retropharyngeal or paratracheal lymph nodes

LYMPHATIC DRAINAGE


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

TheEsophagus

  • Anatomy of the Esophagus

    • Muscular tube about 25 cm long

    • Lined by stratified squamous epithelium

    • Posterior to trachea

    • Penetrates diaphragm at esophageal hiatus

    • Possess upper and lower esophageal sphincters

      • Sphincter—A circular band of muscle that can pinch close a muscular tube


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

TheEsophagus

  • Secretes mucous, transports food – no enzymes produced, no absorption

  • Mucosa – protection against wear and tear

  • Submucosa

  • Muscularis divided in thirds

    • Superior 1/3 skeletal muscle

    • Middle 1/3 skeletal and smooth muscle

    • Inferior 1/3 smooth muscle

    • 2 sphincters – upper esophageal sphincter (UES) regulates movement into esophagus, lower esophageal sphincter (LES) regulates movement into stomach

  • Adventitia – no serosa – attaches to surroundings


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

TheEsophagus

  • A muscular tube; 25 cm in length

    • Collapsed at rest,

    • Flat in upper 2/3 & rounded in lower 1/3

  • Commences at the lower border of the cricoid cartilage.(C6).

  • Descends along the front of the spine, through the posterior mediastinum, passes through the diaphragm, and, entering the abdomen, terminates at the cardiac orifice of the stomach, opposite the eleventh dorsal vertebra.

  • In the newborn upper limit at the level of 4th or 5th cervertb and it ends at 9th dorsal


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

TheEsophagus

  • General direction of the esophagus

  • is vertical.

  • Presents two or three slight curvatures.

  • At commencement, in the median line

  • Inclines to the left side at the root of the neck

  • Gradually passes to the middle line

  • Again deviates to the left


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

TheEsophagus

  • The oesophagus also presents an antero-posterior flexure, corresponding to the curvature of the cervical and thoracic portions of the spine.

  • It is the narrowest part of the alimentary canal, being most contracted at its commencement, and at the point where it passes through the diaphragm.


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

TheEsophagus

  • In the neck, the oesophagus is in relation,

    • in front, with the trachea; and, at the lower part of the neck, where it projects to the left side, with the thyroid gland and thoracic duct;

    • behind, it rests upon the vertebral column and Longuscolli muscle; on each side, it is in relation with the common carotid artery (especially the left, as it inclines to that side), and part of the lateral lobes of the thyroid gland; the recurrent laryngeal nerves ascend between it and the trachea.


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

TheEsophagus

  • In the thorax, it is at first situated a little to the left of the median line: it passes across the left side of the transverse part of the aortic arch, descends in the posterior mediastinum, along the right side of the aorta, until near the Diaphragm, where it passes in front and a little to the left of this vessel, previous to entering the abdomen.


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Narrowings of the Esophagus

  • Oesophagus is the narrowest region of alimentary tract except vermiform appendix. During its course it has three indentations:

    • At 15 cm from incisor teeth is crico-pharyngues sphincter (normally closed) (UES)

    • At 25 cm aortic arch and left main bronchus

    • At 40 cms where it pierces the diaphragm where a physiological sphincter is sited (LES)

15cms

25cms

27cms

40cms


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Narrowing of the Esophagus

Followingsitesaretheareas are where most oesophageal foreign bodies become entrapped.

  • The most common site of oesophageal impaction is at the thoracic inlet

  • Defined as the area between the clavicles on chest radiograph, this is the site of anatomical change from the skeletal muscle to the smooth muscle of the oesophagus.

  • About 70% of blunt foreign bodies that lodge in the oesophagus do so at this location.


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Narrowing of the Esophagus

  • Another 15% become lodged at the mid oesophagus, in the region where the aortic arch and carina overlap the oesophagus on chest radiograph.

  • The remaining 15% become lodged at the lower oesophageal sphincter (LES) at the gastroesophageal junction.


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

TheWall of the Esophagus

  • The oesophageal wall has four layers: From within outwards:

    • Mucous Membrane,

    • Sub-mucosa,

    • Muscle coat and

    • Outer most fibrous layer.

  • Unlike other areas of the gut, it does not have a distinct serosal covering, but is covered by a thin layer of loose connective tissue


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

TheMuscles of the Esophagus

  • Outer longitudinal and inner circular

  • Laimer’s dehiscence/ A triangular area in the wall of the pharynx between the oblique fibres of the inferior constrictor muscle, and the transverse fibres of the cricopharyngeus muscle through which the Zenker'sdiverticulum occurs.


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

TheMuscles of the Esophagus

  • Zenker'sdiverticulum


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Esophagealsphincters

  • Upper Oesophageal Sphincter: It is a 2-3 mm zone of elevated pressure between pharynx & oesophagus. It relates to cricopharyngeal muscle .

  • Lower Oesophageal Sphincter: The LES is located at the junction between the esophagus and stomach, usually localized at or just below the diaphragmatic hiatus. Despite its distinct physiological function, it is not easily distinguished anatomically.


Blood supply lymphatics6

Blood Supply & Lymphatics

Unusual! Arterial supply derived from vessels feeding mainly other organs – thyroid, trachea & stomach.

Cervical Oesophagus: Right & Left superior & inferior thyroid arteries.

Thoracic Oesophagus: Upto tracheal bifurcation right & left inferior thyroid artery

direct supply from aorta (tracheo-bronchial tree)

Abdominal Oesophagus:Branches off left gastric artery and branches of splenic artery posteriorly


Blood supply lymphatics7

Blood Supply & Lymphatics

  • Intra-oesophageal (Intrinsic) Drainage

    • Longitudinally arranged in Submucosa

    • Distal end – portal anastamoses

  • Extra-oesophageal (Extrinsic) Drainage

    • Into locally corresponding veins

    • Inf. thyroid (into innominate vein),

    • Azygos, hemiazygos

    • L gastric & splenic


Blood supply lymphatics8

Blood Supply & Lymphatics

  • The venous supply is also segmental.

  • From the dense submucosal plexus the venous blood drains into the superior vena cava. The veins of the proximal and distal esophagus drain into the azygous system. Collaterals of the left gastric vein, a branch of the portal vein, receive venous drainage from the mid-esophagus.

  • The submucosal connections between the portal and systemic venous systems in the distal esophagus form esophageal varices in portal hypertension. These submucosalvarices are sources of major hemorrhage in conditions such as cirrhosis.


Blood supply lymphatics9

Blood Supply & Lymphatics

LYMPHATIC DRAINAGE

  • In the proximal third of the esophagus, lymphatics drain into the deep cervical lymph nodes,

  • In the middle third, drainage is into the superior and posterior mediastinal nodes.

  • The distal-third lymphatics follow the left gastric artery to the gastric and celiac lymph nodes


Blood supply lymphatics10

Blood Supply & Lymphatics

LYMPHATIC DRAINAGE

  • There is considerable interconnection among these three drainage regions.

    • Poorly understood

    • Important for tumour spread

    • Bi-directional spread

    • Tracheal bifurcation important landmark

  • Of Surgical Interest

    • Submucosallymphatics explain why tumours may extend long distance before obstructing lumen

    • May also explain high recurrence rates

    • Bidirectional lymph flow may explain retrograde tumour seeding if flow is blocked


Nerve supply

Nerve Supply

  • Parasympathetic

    • Vagus – motor to muscular coats & secretomotor to glands

  • Sympathetic

    • From cervical & thoracic sympathetic chain

    • Contraction of sphincters, wall relaxation, peristalsis

  • Intramural

    • Combination of all innervation form plexuses & ganglia

    • In muscular layers (myenteric or Auerbach’s plexus)

    • In submucosa (Meissner plexus)


Nerve supply1

Nerve Supply

  • In muscular layers (myenteric or Auerbach’s plexus)

  • In submucosa (Meissner plexus)


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Swallowing

1. Voluntary Phase

Bolus of food is pushed from the mouth into the oropharynx by forcing the tongue against the hard palate.

2. Involuntary Phase

Chewing and breathing stops.

Food is moved through the oropharynx and laryngopharynx by the successive contraction of the three constrictors.

Food is prevented from entering the nasopharynx by the elevation of the soft palate.

Food is prevented from entering the larynx by elevation of the larynx by the longitudinal pharyngeal muscles and the muscles which elevate the hyoid bone.

Food is prevented from reentering the mouth by the apposition of the tongue with the hard palate.

3. Involuntary

The relaxation of the cricopharyngeus allows the bolus of food to be squeezed into the esophagus


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Swallowing

Passavant ridge (fold = crest)


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Important Relationships

Mastoid Process

Posterior Belly Digastric CN VII

Styloglossus CN XII

Stylohyoid CN VII

Stylopharyngeus CN IX

SC

MC

SC – superior constrictor

MC – middle constrictor


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Important Relationships in Posterior Pharynx

Sympathetic Chain

Superior Cervical Ganglion

CN X

Landmark Carotid

CN XI

CN XII

Superior Root of

AnsaCervicalis

Sympathetic Chain

Middle Cervical Ganglion

CNX

Superior Laryngeal n.

Internal Laryngeal n.

External Laryngeal n.

Superior Laryngeal n. crosses Internal Carotid and splits


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Important Relationships

Stylopharyngeus m.

Glossopharyngeal n.

CN IX

*

CS

Pharyngeal Plexus

CN IX& CNX

Nerve to the Carotid Body

(*) and Carotid Sinus (CS)

(CN IX)

Sensory


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Important Relationships

Occipital a.

Crossed by CN XII

Ascending Pharyngeal a.

On posterior surface of middle and superior constrictors


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

Important Relationships

Occipital a.

Crossed by CN XII

Ascending Pharyngeal a.

On posterior surface of middle and superior constrictors


Wide muscular tube situated behind nose mouth larynx upper part transmits air only

LINE OF ATTACHMENT OF PHARYNX TO BASE OF SKULL


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