Page 64 - Edited - Webster HEAD AND NECK - part 2-Merge PDF

THE PHARYNGEAL CONSTRICTOR MUSCLES (4)
ΗΝ 258 ΗΝ 258
The deficiencies in the lateral muscular walls allow structures to
enter / leave not only the pharynx but also the oral cavity WITHOUT
PIERCING THE CONSTRICTOR MUSCLES. The only exceptions to
this are the tonsilles artery & paratonsillar vein( ). The tensor
muscle of the palate pierces the upper part of the
pterygomandibular raple ( )

Pharyngobasilar fascia
Medial pterygoid STRUCTURES ENTERING NASO-
plate PHARYNX: 1 Auditory (PHARYNGO-
TYMPANIC) TUBE

2 LEVATOR PALATI M. (

STRUCTURES ENTERING ORO-PHARYNX &
ORAL CAVITY:
PTERYGOMANDIBULAR
RAPHE 1. Lingual nerve ( )
SOME IMPORTANT SUPERIOR 2. Glossopharygeal n. ( )
CONSTRICTOR
DISTANCES ORAL 3. Styloglossus m. ( )
1. INCISOR CANITY 8 4 Lingual artery ( )
5.Hypoglossal n. ( )
TEETH/GUMS TO
CRICOID CARTILAGE
(minimum for tracheal MANDIBLE
airway intubation). STRUCTURES ENTERING HYPO-
ADULT: 15 cms (6"). K.E.W. HYOID PHARYNX & LARYNX (1):
1. Superior laryngeal n. (from
NEWBORN: <10cms. BONE VAGUS)
2. FROM CRICOID 2. Laryngeal artery.
CARTILAGE TO
STOMACH
ADULT 25cms (10").
THYROID INFERIOR DEHISCENCE OF
CARTILAGE
KILLIAN
LARYNX
CONSTRICTOR
CRICOID BEGINNING OF OESOPHAGUS IS
CARTILAGE NARROW-SPHINCTERIC ACTION
OF CRICOID PART OF INFERIOR
CONSTRICTORM.
TRACHEA
OESOPHAGUS
K.E.W.
STRUCTURES ENTERING LARYNX (2): Recurrent laryngeal nerve (vagus)

THE DEHISCENCE OF KILLIAN. This is a weakness in the posterior pharyngeal wall, the result of the
subdivision of the inferior constrictor muscle into two parts - one superior, attached largely to the thyroid
cartilage, the other inferior, attached to the cricoid cartilage. The different predominant orientations of
the bundles of skeletal muscle fibres in the two parts create a potential defect posteriorly, covered by
little more than the pharyngo-basilar fascia and mucous membrane. This zone is called the "dehiscence
of Killian" and through it a pouch of food-entrapping mucous membrane may herniate backwards. (Such
a pouch has to be eliminated surgically.) The sphincteric arrangement of the cricoid part of the inferior
constrictor narrows the beginning of the oesophagus (HN162; 280): failure of this muscle to relax during
swallowing while peristalsis in the more superior constrictor muscles continues to push food
downwards promotes the creation of a pouch. Where are the other two narrow parts of the oesophagus?

K.E.W.
kewteach\killian