larynx

LARYNX

• INTRODUCTION• DEVELOPMENT OF LARYNX• SKELETAL FRAMEWORK• SUBDIVISON OF LARYNX• MUSCLES• HISTOLOGY• BLOOD SUPPLY• NERVE SUPPLY• LYMPHATIC DRAINAGE• APPLIED ANATOMY

SITUATION AND EXTENT

MEASURMENTS-

Male larynx V=44mm,T=43 mm,AP=36mm

Female larynx V=36mm,T=41 mm,AP=26mm

DEVELOPMENT

• Laryngotracheal tube

ventral wall of primitive pharynx-

28 days of development

• 4th arch-thyroid,cunieform, corniculate

5th arch- cricoid

6th arch- arytenoid

Epiglottis- caudal part of hypobranchial eminence

Muscles- 4 & 6 arches

CARTILAGES

Paired • Arytenoid• Corniculate• Cuneiform• Cartilago triticea

Unpaired

• Thyroid• Cricoid• Epiglottis

5

THYROID CARTILAGE

ANTERIOR ASPECT

POSTERIOR ASPECT

LATERAL ASPECT

EPIGLOTTIS

CRICOID CARTILAGE

ARYTENOID CARTILAGE

CORNICULATE AND CUNEIFORM CARTILAGE

Corniculate cartilage of Santorini

Cunieform cartilage of Wrisberg

Cartilage Tritiate

TRITIATE CARTILAGE

JOINTS:

Lateral View Antero-superior View

• CRICOTHYROID JOINT • CRICOARYTENOID JOINT

• ARTENOCORNICULATE JOINT

MEMBRANES & LIGAMENTS

• Extrinsic • Thyrohyoid

• Cricotracheal

• Thyroepiglottic

• Hyoepiglottic

• Intrinsic

• Quadrangular membrane & vestibular ligament

• Cricovocal membrane & vocal ligament

EXTRINSIC

• Thyrohyoid

• Cricothyroid

• Cricotracheal

Sagittal section showing interior of left half of larynx

EXTRINSIC

Hyoepiglottic Ligament

Thyroepiglottic Ligament

INTRINSIC

Sagittal section of left side of larynx showing laryngeal membranes

Coronal section through the larynx and cranial end of trachea Posterior aspect

SUBDIVISIONS OF LARYNGEAL CAVITY

LARYNGEAL INLETARYEPIGLOTTIC FOLD

SACCULEVESTIBULAR FOLDVOCAL FOLD

PARALUMENAL SPACES

Pre-epiglottic space

Paraglottic space

Subglottic space

EXTRINSIC MUSCLES

Extrinsic attached to hyoid (Depressors)

– Sternothyroid– Sternohyoid– Thyrohyoid

Extrinsic attached to thyroid (Elevators )

– Palatopharyngeus

– stylopharyngeus

INTRINSICMuscles acting on VC

– Length and tension• Cricothyroid• Thyroarytenoids

– Abductor• Post cricoarytenoid

– Adductors• Lateral cricoarytenoid• Thyroarytenoid• Interarytenoideus

Muscles acting on epiglottis– Aryepiglotticus– Thyroepiglotticus

CRICOTHYROID MUSCLE

Posterior Aspect Superior Aspect

POSTERIOR CRICOARYTENOID MUSCLE

LATERAL CRICOARYTENOID MUSCLE

OBLIQUE ARYTENOID MUSCLE and ARYEPIGLOTTICUS

TRANSVERSE ARYTENOID MUSCLE

THYROARYTENOID and VOCALIS MUSCLE

SHAPE OF RIMA GLOTTIDIS DURING DIFFERENT MOVEMENTS OF VOCAL CORDS

DURING PHONATION DURING WHISPERING

NERVE SUPPLY

Internal Laryngeal Nerve :

only sensory

External Laryngeal Nerve :

only motor

Recurrent Laryngeal Nerve : sensory and motor

ARTERIAL SUPPLY

Sup Laryngeal Artery

Inferior Laryngeal Artery

VENOUS DRAINAGE

Sup Thyroid Vein

Inf Thyroid Vein

LYMPHATIC DRAINAGE

• Above VC upper deep cervical {anterosuperior group}

• Below VC lower deep cervical {posteroinferior group}

Upper deep cervical

Lower deep cervical

HISTOLOGY

• Histology of Supraglottis• Epithelium• Mucous glands• Rich vascularity & lymphatic• Histology of Glottis• Epithelium• Lamina propria – 3 layers• Muscle layer- vocalis• No mucous gland in free edge of vocal cord• Cartilages

HISTOLOGY OF EPIGLOTTIS

•Epithelium•Lamina propria•cartilage

INFANT LARYNX

• Size• Position• Cavity- funnel shaped & short• Laryngeal cartilages-softer & pliable• Epiglottis• Thyroid• Vocal cord

APPLIED ANATOMY

CONGENITAL ANOMALIES OF LARYNX :CLASSIFICATION

• 1. SUPRAGLOTTIS LARYNGOMALACIA LARYNGEAL CYST CONGENITAL LARYNGOCELE 2. GLOTTIS LARYNGEAL WEB VOCAL CORD PARALYSIS 3. SUBGLOTTIS: SUBGLOTTIC STENOSIS LARYNGOTRACHEAL CLEFT

LARYNGOMALACIA

• Excessive flaccidity of supraglottic larynx• OMEGA SHAPED EPIGLOTTIS

LARYNGEAL CYST

• fluid filled smooth swelling in Supraglottic larynx

LARYNGOCELE

Air filled dialatation of saccule

ANTERIOR GLOTTIC WEB

•Due to incomplete recanalisation of larynx

LARYNGEAL WEB

• SUBGLOTTIC STENOSIS

Abnormal thickening of cricoid cartilage or fibrous tissue seen below vocal cords

Requires laryngeal mirror and head mirror

Structures seen……………

LARYNGOSCOPY-

Indirect Laryngoscopy

Done under GA

Before endotracheal intubation

Direct Laryngoscopy

SINGERS /SCREAMERS/CLERGYMENS NODULES

REINKE’S EDEMA

CLASSIFICATION OF LARYNGEAL PARALYSIS

• May be unilateral or bilateral and may involve

1. Recurrent laryngeal nerve2. Superior laryngeal nervea. External LNb. Internal LN

LARYNGEAL OBSTRUCTION

LARYNGOTOMY

INFLAMMATION OF LARYNX

MALIGNANCY OF LARYNX

• Supraglottic• Glottic• Subglottic