Suprahyoid Neck Flashcards
What are the boundaries of the nasopharynx?
Anterior: Posterior nasal cavity at the nasal choana
Posterosuperior: Lower clivus, upper cervical spine, and prevertebral muscles
Inferior: Divided from the oropharynx by a horizontal line drawn along the hard and soft palates
Lateral wall: Composed of the torus tubarius (cartilaginous eustachian tube), the eustachian tube orifice, and the mucosa of the lateral pharyngeal recess (fossa of Rosenmuller)
What are the boundaries of the oropharynx?
Anterior: A ring structure of structures separates the oropharynx from the oral cavity. This ring includes the circumvallate papillae of the tongue the anterior tonsillar pillars, and the soft palate. The lingual tonsil is in the oropharynx and not the oral cavity.
Posterior: Superior and middle constrictor muscles
Inferior: Separated from the larynx by the epiglottis and glossoepiglottic fold and from the hypopharynx by the pharyngoepiglottic fold
Superior: The soft palate forms the roof of the oropharynx
What are the layers of deep cervical fascia in the suprahyoid neck?
- Superficial layer (investing fascia)
- Middle layer (buccopharyngeal fascia)
- Deep layer (prevertebral fascia)
What are the spaces defined by the three layers of deep cervical fascia?
- Parapharyngeal space
- Pharyngeal mucosal space
- Masticator space
- Parotid space
- Carotid space
- Retropharyngeal space
- Perivertebral space
All but two spaces of the suprahyoid neck are true fascia-enclosed spaces; that is, they are completely circumscribed by the three layers of deep cervical fascia. What are the two exempted space?
The parapharyngeal space and the pharyngeal mucosal space
These two spaces have complex fascial borders with multiple fascia constituting the space margins.
This is the central space of the deep face, around which most of the other important spaces are situated. The surrounding spaces include the pharyngeal mucosal, masticator, parotid, carotid, and lateral retropharyngeal spaces.
Parapharyngeal space (PPS)
Because the contents of the PPS are limited, few lesions actually arise in this space. Rather, most infections and tumors found in the PPS originate in one of the surrounding spaces.
What are the contents of the parapharyngeal space?
Fat
Internal maxillary artery
Ascending pharyngeal artery
Pharyngeal venous plexus
The PPS has no mucosa, muscle, bone, nodes, or normal salivary gland tissue wtihin its boundaries. As a result it is unusual for a disease process to originate in the PPS
What are the fascial margins of the PPS?
Medial fascial margin = made up of the middle layer of deep cervical fascia as it curves around the lateral sided of the pharyngeal mucosal space
Lateral fascial margin = formed by the medial slip of the superficial layer of deep cervical fascial as it curves around the deep border of the masticator and parotid spaces.
Posteriorly = made up of the anterior part of the carotid sheath, which is made up of all three layers of the deep cervical fascia
What are the contents of the pharyngeal mucosal space?
Mucosa Lymphoid tissue of Waldeyer's ring (adenoids, tonsils) Minor salivary glands Pharyngobasilar fascia Superior and middle constrictor muscles Salphingopharyngeus muscle Levator palatini muscle* Cartilagenous end of the eustachian tube*
- The levator palatini muscle and the eustachian tube originate outside the PMS from the skull base
This fascia attaches the superior constrictor muscle to the skull base.
Pharyngobasilar fascia
Along the superior aspect of the posterolateral margin of the pharyngobasilar fascia is a notch called ______.
Through this notch the levator palatini muscle and the eustachian tube pass on their way from the skull base to the PMS.
Sinus of Morgagni
The cartilaginous opening of the eustachian tube within the PMS is referred to as what?
Torus tubarius
What are the contents of the masticator space?
Muscles of mastication:
- Masseter muscle
- Temporalis muscle
- Medial pterygoid muscle
- Lateral pterygoid muscle
Masticator nerve branches (Proximal V3 motor branch)
Inferior alveolar nerve (V3 sensory branch)
Inferior alveolar vein and artery
Ramus and posterior body of the mandible
What are the bordering spaces of the masticator space?
Anterior = Buccal space
Posteromedial = Parapharyngeal space
Posterior = Parotid space
What are the contents of the parotid space?
Parotid gland Fascial nerve (CN VII) Retromandibular vein External carotid artery Intraparotid lymph nodes