Anatomy of Pharynx and larynx

1. 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:
1. Thyroid cartilage
2. Epiglottis
3. Cricoid artilage
4. Arytenoid cartilage
5. Corniculate cartilage Paired
6. Cuneiform cartilage
Occur singly

9. 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)

10. 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.

11. 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.

12. THANK YOU