Anatomy of pharynx and larynx

Anatomy of Pharynx and larynx

1. ANATOMY OF PHARYNX AND LARYNX Ms.Anu Sebastian: B.Pharm ; M.Pharm Assistant Professor, Dept. Of Pharmacology Nirmala College Of Pharmacy Muvattupuzha,Ernakulam,Kerala

2. PHARYNX It is funnel shaped tube of 13cm. It begins at the internal nares & ends at cricoid cartilage of larynx. It is made up of skeletal muscles& lined with mucous membrane. Location Anteriorly : Nasal & oral cavities Posteriorly : Cervical vertebrae Inferiorly: Larynx Superiorly: Internal nares Functions Acts as a passageway for air & food. Provides a resonating chamber for speech sounds. Houses tonsils which participate in immunological reactions against foreign invaders.

3. Fig: Strucure of Pharynx

4. Pharynx is having 3 regions: Nasopharynx Oropharynx Laryngopharynx Nasopharynx It is superior; portion, posterior to nasal cavity ; It extends to soft palate. Its wall is having 5 openings; 2 internal nares , 2 openings to eustachian tube and one to oropharynx . It houses pharyngeal tonsil. It is lined with pseudostratified ciliated epithelium. Equilizes pressure in middle ear with external.

5. Oropharynx It is posterior to oral cavity. It extends from soft palate to hard palate. It acts as passageway for both respiratory & digestive systems. It is having an opening from mouth- Fauces . It is lined by non-keratinized stratified squamous epithelium. Laryngopharynx It begins at the hyoid bone. It opens into oesophagus posteriorly & into larynx anteriorly . It is lined by non keratinized stratified squamous epithelium. It also acts as a passageway for both respiratory & digestive systems.

6. LARYNX/VOICE BOX It is short passageway that connects laryngopharynx with trachea. It lies in the middle of neck. Posteriorly : Esophagus & cervical vertebrae The wall of larynx is composed of 9 cartilages: Thyroid cartilage Epiglottis Cricoid artilage Arytenoid cartilage Corniculate cartilage Paired Cuneiform cartilage Occur singly

7. Thyroid cartilage It consist of 2 fused plates of hyaline cartilage. It forms the anterior wall of larynx. It is larger in male compared to female due to the influence of male sex hormone. It is connected to hyoid bone through thyrohyoid membrane. Epiglottis It is a large leaf shaped piece of elastic cartilage covered with epithelium. The stem (inferior portion) is attached to thyroid cartilage & hyoid bone; but the leaf is unattached. Glottis: It consist of a pair of folds of mucous membrane (True vocal folds)

8. Cricoid cartilage It is a ring of hyaline cartilage that forms the anterior wall of larynx. It is attached to the first ring of tracheal cartilage by cricotracheal ligament. The thyroid & cricoid cartilages are attached by cricothyroid ligament. Arytenoid cartilage Triangualr pieces of hyaline cartilage;located on suprior & posterior border of cricoid cartilage. They attach to vocal folds & intrinsic pharyngeal muscles. With the support of arytenoid cartilages, the intrinsic pharyngeal muscles contract & move the vocal folds to produce sounds.

9. Corniculate cartilage It is horn shaped pieces of elastic cartilage. It is located at the apex of arytenoid cartilage. It also acting as a supporting structure for epiglottis. Cuneiform cartilage It is club shaped elastic cartilage. It is anterior to corniculate cartilage. It supports vocal folds & epiglottis.

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