Overview
- Presenter: Nader ALDajani
- Topic: Pharynx I & II
Pharynx
- Shape: Funnel-shaped
- Extent: From the base of the skull to the level of the 6th cervical vertebra at the lower border of cricoid cartilage.
- Length: 10 cm
Structure
- Layers:
- Mucous membrane
- Submucosa
- Muscular layer (External and Internal)
- Adventitia
- Mucous Membrane Types:
- Ciliated epithelium
- Stratified squamous epithelium
- Transitional epithelium
- Subepithelial Lymphoid Tissue: Waldeyer’s ring
Nasopharynx
- Location: Opens anteriorly to the nose.
- Boundaries:
- Above: Base of skull
- Below: Soft palate
- Laterally: Opening of the eustachian tube, Pharyngeal recess (fossa of Rosenmuller)
Oropharynx
- Location: Opens anteriorly to the mouth.
- Boundaries:
- Above: Soft palate
- Below: Upper border of epiglottis
- Contains: Palatine tonsils between the anterior and posterior pillars.
Hyopharynx (Laryngopharynx)
- Location: Opens anteriorly to the larynx.
- Boundaries:
- Above: Upper border of the epiglottis
- Below: Lower border of cricoid cartilage
- Contains: Pyriform fossa, valleculae
Lymphoid tissue
Functions of the sub epithelial lymphoid tissue: - Protective functions - Formation of lymphocytes - Formation of antibodies - Acquisition of immunity - Localization of infection
Palatine Tonsils
- Location: Part of the Oropharynx
- Features: Contains 12 to 15 crypts
- Separation: Deep surface separated from constrictor muscles by connective tissue capsule
Other Lymphoid Tissue
- Types:
- Adenoid (no capsule)
- Lingual tonsils
- Tubal tonsils
- Lateral pharyngeal bands
- Discrete nodules
Muscles
External Muscles
- Constrictor Muscles:
- Superior constrictor: Arises from pterygoid, pterygomandibular ligament, posterior end of mylohyoid fibers
- Middle constrictor: Arises from the hyoid bone and stylohyoid ligament
- Inferior constrictor: Thyropharyngeus, Cricopharyngeus
- Killian’s Dehiscence: Potential gap between thyropharyngeus and cricopharyngeus
zenkers diverticulum, barium swallow, laryngeal pouch, management; …
Internal Muscles
- Muscles:
- Stylopharyngus
- Salpingopharyngus
- Palatopharyngus
