Pharynx

pharynx

Funnel shaped musculomembranous tube extended from the skull base to the oesophagus opposite the sixth cervical vertebra

Pharynx

Nasopharynx Oropharynx Hypopharynx.

Nasopharynx

From base of skull to soft palate Walls structures Pharyngeal opening of the eust.tube Pharyngeal recess/ fossa of rosenmuller Nasopharyngeal tonsil

oropharynx

From soft palate to the upper border of the epiglottis Lat. Wall contains palatoglossal , palatopharyngeal arches & palatine tonsil in between

hypopharynx

From upper border of epiglottis to the lower border of the cricoid cartilage. From 3rd to 6th cx. vert. Supported by thyroid cartilage & thyrohyoid membrane

Nerve supply

Motor: * cranial part of the XI nerve & vagus n (X) ** glossopharyngeal n (IX) to stylopharyngeus muscle only 2. Sensory : - maxillary n from the nasal part - glossopharyngeal n.---oral part - internal laryngeal n of the vagus from the laryngeal part

Blood supply

Ascending pharyngeal a. Ascending palatine Facial a. Maxillary a Lingual a

Veinous drainage : pharyngeal pluxes to int.jug.v.

Lymphatic drainage: #- deep cx. Ln. #- retropharyngeal #- parapharyngeal Ln - subepithelial lym. t. (Waldeyer`s ring): 1-palatine ts. 2-n/p ts ( adenoid) 3- lingual ts. 4- tubal ts. 5- lateral pharyngeal band.

Palatine tonsil

Two masses of lymphoid tissue located in the lat. wall of the oropharynx between ant. & post. Faucial pillars The free medial surface project into the cavity of pharynx and pitted by numerous small opening lead into crypts in which the mucous glands are secreting Lat. Surface covered by fibrous tissue called capsule

Swallowing (deglutition)

Oral phase Pharyngeal phase Oesophageal phase.

Oral phase

Preparatory stage: - food or drink in the mouth - coordination of the lip, buccal, mandibular, & tongue movements - voluntary control - cr ns ;- Vth (sens,mastication) - VIIth( lip ,buccal) - Xth (oropharyngeal sphinctor) - XIIth (tongue )



Propulsive stage: - bolus between the tongue & hard palate - contraction from the tip of the tongue pushing against the hard palate - relaxation of the oropharyngeal sphinctor ,rising of the soft palate & dropping of the post. 1/3rd of the tongue>>>bolus into the oropharynx

Pharyngeal phase

pharyngeal peristalsis / propulsive force Two key elements; 1-tongue driving force 2-hypopharyngeal suction * elevation of the Lyx * change in the pressure at the cricopharyngeal sphinctor * closure of Lyx & nyx * relaxation of the cricopharyngeal sphinctor

Oesophageal phase

Relaxation of cricopharyngeal sph. Oesophageal peristalsis