Pharynx and esophagus

ByProf. Dr. Ansari

Chairperson &Prof. AnatomyRAKCOMS

The Pharynx

• Is a fibromuscular tube which extends from the base of the skull to the lower border of the cricoid cartilage.

• At this point it becomes the esophagus.• Portions of the pharynx lie posterior to the nasal cavity (nasal pharynx), oral cavity (oral pharynx), and larynx (laryngeal pharynx).

The nasopharynx shows:-• The opening of the pharyngotympanic

(auditory or Eustachian) tube. This ostium is formed superiorly by the prominence of the cartilage of the auditory tube.

• The salpingopharyngeal fold which covers the salpingopharyngeus muscle.

• Immediately posterior and superior to the salpingopharyngeal fold, identify the pharyngeal recess.

• Locate the pharyngeal tonsil or “adenoids” that lie in the roof and posterior wall of the nasopharynx.

• This lymphatic tissue may be enlarged during childhood and obstruct air passage from the nasal cavity to the pharynx.

The oropharynx

The soft palate is made up of 5 group of muscles

• Palatoglossus• Palatopharyngeus• Tensor veli palatini• Musculus uvelae• Levator veli palatini• All palatine muscles are supplied

by pharyngeal plexus, except TVP=mandibular nerve.

• The palatine tonsils are located in the tonsillar fossa.

• It forms the part of Waldeyer’s ring, that guards the food/respiratory passages.

Laryngopharynx lies posterior to larynx

The pharyngeal constrictors

• There are three constrictors, superior, middle and inferior pharyngeal constrictors.

Above the superior pharyngeal constrictor:

• auditory tube (AT)• levator palati (LP)• ascending palatine artery (APA)

Between the superior and middle constrictors:

• stylopharyngeus muscle (SP)• glossopharyngeal nerve (IX)

Between the middle and inferior constrictors:

• internal laryngeal branch of the superior laryngeal nerve (IL)

• superior laryngeal artery from the superior thyroid artery (SLA)

Below the inferior constrictor:

• inferior laryngeal nerve ( ILN) (recurrent laryngeal branch of the vagus)

• inferior laryngeal artery (ILA) (inferior thyroid)

Nerve supply of pharynx

Sensory innervation:-• The pharyngeal plexus provides sensory innervation of the

oropharynx and laryngopharynx from CN IX and CN X.• The nasopharynx is innervated by CN V2.Motor nerve supply:-• The pharyngeal plexus, with fibers from CN IX, CN X, and cranial

part of CN XI, innervates all the muscles of the pharynx (except stylopharyngeus, which is innervated directly by a branch of CN IX).

• This includes the following muscles: palatopharyngeus, palatoglossus, musculus uvulae, the pharyngeal constrictors, salpingopharyngeus.

The esophagus

• The laryngopharynx follows the esophagus, below the lower border of cricoid cartilage/C6 vertebra posteriorly.

• For convenience sake it is divided into three parts:-

• Proximal 1/3rd, middle 1/3rd and distal 1/3rd.

• It pierces the diaphragm and forms the abdominal part of diaphragm

The esophagus

• Is a muscular tube about ten inches (25 cm.) long, extending from the hypopharynx to the stomach.

• The esophagus lies posterior to the trachea and the heart and passes through the mediastinum and the hiatus, an opening in the diaphragm, in its descent from the thoracic to the abdominal cavity.

• The esophagus has no serosal layer; tissue around the esophagus is called adventitia.

Three regions of esophagus

Cervical begins at the lower end of pharynx (level of 6th vertebra or lower border of cricoid cartilage) and extends to the thoracic inlet (suprasternal notch); • It is 18 cm from incisors.

Thoracic part:- from thoracic inlet to GE junction, including abdominal esophagus.

Abdominal part:-Considered part of lower thoracic esophagus.

Malignancy sites:-• Upper third (10% of

esophageal cancers)• Middle third (40%)• Lower third (50%).

References

• http://biology.clc.uc.edu/fankhauser/labs/microbiology/strep_detection/oropharynx_P2253089_lbd.JPG

• http://www.healthhype.com/pharynx-functions-anatomy-pictures-disorders.html

• http://ak47boyz90.wordpress.com/2010/08/15/l1-anat-pharynx/

• http://home.comcast.net/~wnor/lesson8.htm

• http://training.seer.cancer.gov/ugi/anatomy/esophagus.html

• http://missinglink.ucsf.edu/lm/IDS_106_UpperGI/Upper%20GI/ecases/ecase2.htm