PHARYNX Dr. Jamila -ELmedany

EXTENSION It is a fibro muscular tube that lies behind: Nose. Mouth. Larynx. It extends from : Base of the skull To 6th cervical vertebra.

SHAPE It is Funnel shaped. It has: Upper expanded end that lies under the skull and A narrow lower end that becomes continuous with the Esophagus.

RELATIONS Posterior: Prevertebral muscles and fascia. Lateral: (1) Auditory tube. (2) Styloid process and its muscles.

RELATIONS (3) Carotid sheath and its contents. (4) Thyroid gland.

ANTERIOR RELATIONS It is deficient. It is replaced by: Posterior nasal openings. Oropharyngeal isthmus. Inlet of the larynx.

STRUCTURE OF THE WALL 1. Mucosa : Continuous with that of the nose ,auditory tube, oral cavity , larynx and esophagus. 2. Fascia: Thickened Internally: Paryngobasilar fascia. Externally: Buccopharynge fascia. 3. Muscles : circular & longitudinal.

CIRCULAR MUSCLES CONSTRICTORS: Superior. Middle. Inferior. They propel the bolus of food down into the esophagus. They overlap like three glasses stacked one inside the other.

CONSTRICTORS Each one fans out from its anterior attachment and passes posteriorly around the pharynx. They join each other in the: Pharyngeal Raphe A fibrous midline raphe which extends from the occipital bone to the esophagus.

CRICOPHARYNGEUS It is the lowest fibers of the inferior constrictor muscle. Action : 1. A sphincter on the lower end of the pharynx. 2. Prevents the entry of air into the esophagus in between swallowing.

LONGITUDINAL MUSCLES Stylopharyngeus. Salpingopharyngeus. Palatopharyngeus. Origins : Styloid process . Pharyngotympanic tube. Soft palate.

LONGITUDINAL MUSCLES Insertion: To the pharyngeal wall. Action: 1. Elevate the larynx and pharynx. 2. Pull the pharynx forward during swallowing and speaking.

STRUCTURES THROUGH GAPS (1) Between: Base of the skull and the superior constrictor : Pharyngobasilar fascia. Tensor palati. Levator palati.

STRUCTURES THROUGH GAPS (2) Between: Superior and Middle constrictors: It is a triangular gape . It allows : A. muscles, vessels & nerves to pass between the tongue and regions lateral to pharynx. B. Stylopharyngeus tendon to slip into the pharynx.

STRUCTURES THROUGH GAPS (3) Between: Middle & Inferior constrictors: Internal laryngeal nerve & superior laryngeal vessels. (4) Below: Inferior constrictor: The recurrent laryngeal nerve &inferior laryngeal vessels.

SUBDIVISIONS OF PHARYNX

NASOPHARYNX It has a respiratory function. It is Behind the posterior nasal openings (Choanae) AND Above the Soft palate.

BOUNDARIES Roof: Basilar part of occipital bone. Body of sphenoid. It has A collection of lymphoid tissue (pharyngeal tonsil) in its submucosa.

BOUNDARIES Floor : Sloping upper surface of the soft palate. Posterior wall: Anterior arch of atlas. Anterior : Choanae.

PHARYNGEAL ISTHMUS It is a gap in the floor between the free end of the soft palate and the posterior wall. It is closed in swallowing by the elevation of the soft palate and pulling forward of the posterior wall.

BOUNDARIES Lateral wall : 1. Pharyngeal opening of the auditory tube. 2.Tubal elevation: The elevated posterior margin of the tube. Pharyngeal Recess : It is a slit like depression on each side behind the tubal elevation.

LATERAL WALL 3. Salpingo-pharyngeal fold of mucous membrane produced by the salpingopharyngeal muscle. 4.Tubal tonsil: It is a collection of lymphoid tissue behind the opening of the auditory tube.

ADENOID Hypertrophy and infection of the pharyngeal tonsils. It causes: obstruction of the posterior nasal openings. The patient: breathes through the mouth and snores loudly at night. It can cause: deafness and recurrent otitis media due to its close relation to the auditory tube.

OROPHARYNX It is behind the mouth cavity. It extends from: Soft palate TO The upper border of the Epiglottis.

BOUNDARIES Roof : It is the under surface of the soft palate and the pharyngeal isthmus. It has collection of lymphoid tissue.

BOUNDA RIES Floor : Posterior 1/3 of the tongue & the interval between the tongue and the anterior surface of the epiglottis. Lingual tonsil : A collection of lymphoid tissue on the posterior 1/3 of the tongue.

BOUNDARIES Lateral wall : Palatoglossal arch A mucous fold overlying the palatoglossal muscle. It marks the boundary between the oral cavity and the oropharynx. The arched opening between the two folds is the Oropharyngeal isthmus.

LATERAL WALL Palato-pharyngeal arch A mucous fold behind the palatoglossal arch. It overlies the palatopharyngeal muscle.

BOUNDARIES Anterior : It opens into the mouth cavity through the oropharyngeal isthmus. Posterior wall : Body of 2nd cervical vertebra. The upper part of the body of the 3rd vertebra.

PALATINE TONSILS Two oval bodies of lymphoid tissue. They have their maximum size in childhood. They lie on each side in the tonsilar sinus in the lateral wall of the oropharynx between the palatoglossal arches (anterior) and palatppharyngeal arches (posterior)

PALATINE TONSILS They lie on the mucosa lining the Superior Constrictor muscle. The capsule is separated from the superior constrictor muscle by loose fascia.

PALATINE TONSILS This fascia contains: The External palatine vein. The Facial artery is lateral to the muscle. The Internal carotid artery lies about 1’’ (2.5) cm behind and lateral to the tonsil.

BOUNDARIES Superior: Soft palate. It is continuous with the lymphoid tissue on its undersurface . Inferior : Posterior third of tongue. It is continuous with the lingual tonsil.

BLOOD SUPPLY Arterial : Tonsillar arteries from : Facial. Ascending palatine. Venous Drainage: External palatine vein. Pharyngeal venous plexus. Pharyngeal and Facial veins.

LYMPH DRAINAGE Juglodigastric nodes: Below and behind mandible.

SENSORY SUPPLY Glossopharyngeal nerve supplies its mucosa.

TONSILITIS The tonsils are a common site of infection. Sore throat , Pyrexia and Tender Enlarged juglodigastric lymph nodes. After tonsilectomy The external palatine vein may be the source of postoperative bleeding.

QUINSY It is a Peritonsilar abscess. It is due to the spread of infection from the palatine tonsil to the loose connective tissue outside the capsule.

LARYNGOPHARYNX It extends from: The upper border of the epiglottis and pharyngoepiglottic fold TO The lower border of the cricoid cartilage(C6).

BOUNDARIES Anterior : Inlet of the larynx. Posterior wall: Bodies of 3rd , 4th ,5th and 6th cervical vertebrae. Lateral wall: Thyroid cartilage. Thyrhyoid membrane.

VALLECULAE Pair of mucosal pouches anterior to the cavity of laryngopharynx. They are between: The base of the tongue AND The epiglottis. One on each side between the median and lateral glossoepiglottic folds.

PIRIFORM FOSSAE Pair of mucosal recesses. Between: medially The central part of the larynx from which it is separated by the aryepiglottic fold. laterally The thyroid cartilage and thyroyhyoid membrane.

PIRIFORM FOSSA Function: It is an important channel that directs solids and liquids from the oral cavity around the raised laryngeal inlet into the esophagus. A foreign body in the fossa causes the patient to gag violently.

NERVES RELATED TO THE FOSSA Branches of internal & recurrent Laryngeal nerves lie deep to its mucous membrane. Nerve injury: They are liable to be injured when a foreign body ( bony fish) is lodged in the fossa.

ARTERIAL SUPPLY The following arteries supply the pharynx : 1. Ascending pharyngeal. 2. Ascending palatine. 3. Facial. 4. Maxillary. 5. Lingual.

VENOUS DRAINAGE The pharynx is drained through the Pharyngeal venous plexus. The plexus drains: Superiorly: into the Pterygoid venous plexus. Inferiorly: into the facial and internal jugular veins.

NERVE SUPPLY Most of the Motor and sensory supply of the pharynx is through nerves which form the pharyngeal plexus.

PHARYNGEAL PLEXUS Formed from: Pharyngeal branches of the Vagus. Branches from External laryngeal nerve (from superior laryngeal). Pharyngeal branches of Glossopharyngeal. Sympathetic fibers

STYLOPHARYNGEUS MUSCLE The only muscle of the pharynx which is innervated directly by a branch of the Glossopharyngeal nerve.

SENSORY NERVE SUPPLY Nasopharynx : pharyngeal branch of Maxillary nerve. Laryngopharynx: pharyngeal plexus (Vagus nerve). Oropharynx : pharyngeal plexus (Glossopharyngeal nerve).

LYMPH DRAINAGE Direct to: Deep cervical nodes. Indirect to : Retropharyngeal. Paratracheal nodes. The lymphoid tissue of the pharynx is generally enlarged in childhood.

Revision Questions 1. The palatine tonsils: a. Related to the superior constrictor of the pharynx. b. Borderd anteriorly by the palatoglossus muscle. c. Receives some of its blood supply from the facial artery. d. Lies in the oral cavity. e. The internal carotid artery is at its lateral side.

Revision Questions 2. Each of the following is related to the walls of the laryngeal part of the pharynx EXCEPT: a. Piriform fossa. b. Cricoid cartilage. c. Thyrohyoid membrane. d. Thyroid cartilage. e. Palatine tonsil

Revision Questions 3. The pharynx: a. Extends from the base of the skull to the 4th cervical vertebra. b. It is supported externally by the pharyngobasilar fascia. c. It is related posteriorly to the prevertebral fascia. d. It is related anteriorly to the pretracheal fascia. e. Its muscles have motor supply from the pharyngeal plexus

Revision Questions 4. The inferior constrictor muscle of the pharynx has nerve supply from: a. Accessory nerve. b. Hypoglossal nerve. c. Internal laryngeal nerve. d. Pharyngeal plexus. e. Ansa cervicalis.

Revision Questions 5. The piriform fossa is: a. Located above the pharyngeal tonsil. b. Located within the pharyngobasilar fascia. c. Located on each side of the larynx. d. Located posterior to the salpingopharyngeal fold. e. Related laterally to the cricoid cartilage.

Revision Questions 6. Structures entering the pharynx between the superior and middle constrictor muscles are: a. Recurrent laryngeal nerve. b. Internal laryngeal nerve. c. Glossopharyngeal nerve. d. Superior laryngeal artery. e. Inferior laryngeal artery.

Revision Questions 7. The middle constrictor muscle: a. Lies inner to the superior constrictor. b. Attached anteriorly to the pharyngeal raphe. c. The internal laryngeal nerve is between it and the inferior constrictor. d. The stylopharyngeus muscle passes between it and the superior constrictor. e. Propels the bolus of food down into the esophagus.

Revision Questions 8. Palatine tonsil: a. Its lymph drainage is to the submandibular lymph nodes. b. Lies in the oral cavity. c. Lies on the middle constrictor. d. The palatopharyngeal arch is anterior to it. e. Its venous blood drain into the external palatine vein.

Revision Questions 9. Interior of the pharynx: a. Receives a sensory innervation from the maxillary nerve. b. Has the palatine tonsil in the lateral wall. c. Has an anterior extension on each side of the larynx known as the vallecula. d. Has a ridge formed by the salpingopharyngeus muscle. e. The pharyngeal tonsil is a collection of lymphoid tissue on its roof.

Revision Questions 10. The following arteries supply the pharynx EXCEPT: a. Ascending palatine. b. Sphenopalatine. c. Ascending pharyngeal. d. Lingual. e. Maxillary.