ENT ANATOMY and PHYSIOLOGY OF AERODIGESTIVE TRACT Page 1 of 1

ANATOMY and PHYSIOLOGY OF AERODIGESTIVE TRACTDra. Clydine G. Barrientos090409

Anatomy- Mucosally lines neuromuscular tube- Begins lower neck- Traverse mediatinum- Ends stomach- 20-25cm long

Segments- Upper 3rd – 10% esophageal cancer- Mid 4rd – 40- Lower – 50

Regions: cervical- 4-5cm long - Lower end of pharynx

o CV6 o Below cricoid cartilage

- Thoracic inleto Suprasternal notcho Shifts to left

Thoracic- Upper

o Thoracic inlet to level of tracheal bifurcation

o TV 4 Opposite the sterna angle Pushed to midline by aorta

- Mid - Lower

Abdominal – T11

3 Physiologic Sphincters- UES

o Cricopharyngeus – ONLY TRUE sphincter

- LES- GE junction

*for foreign body ingestion

Zenker’s diverticulum – outpouching

TRACHEA- TV5- 1st tracheal ring – broader- Respiratory ep[ithelium – warms and moistens

the air- Cartilaginous layer- CN10 – parasympathetic- Sympathetic trunk

BRONCHI- Common in left- children

- Common in right – adult- Right –below and in front- Left – above and in front

Physiology-

Pharyngeal stage - Most critical stage

8-20secs – peristalsis90% during expiration - swallow

- Zline – jxn bet str sq and columnar epith - Control peristalsis – Auerbach’s plexus- External muscular coat – ICOL, striated, mixed,

smootho Impt in carcinomas

- Sensory input regulation and regulate secretion- Submucosa – dense collagenous CT, Meissner’s

plexus (moves the bolus down), regulates secretions

- 17 degrees – to midline - Inc in smooth muscles (reduction in diameter)- Pharyngeal space – most critical stage- Fine muscular control of tongue – most

important action of the tongue- Prolong cricopharyngeal opening and oral

transit timeo Elderly