1) General Organisation of Head & Neck Flashcards
What are the palpable features of the anterior neck?
Hyoid bone, thyroid cartilage and cricoid cartilage
What is the function of the thyroid and cricoid cartilage?
Support and protect underlying larynx
What muscles attach at the hyoid bone?
Supra and infra-hyoid muscles
What are the three main muscles of the neck?
Platysma
Sternocleidomastoid
Trapezius
Describe the position of platysma:
Anterolateral neck, superficial
Overlies sternocleidomastoid
What is the function of platysma?
Draws corners of mouth inferiorly
Draws skin of neck superiorly
What is the nerve supply to platysma?
Facial nerve
What are the functions of sternocleidomastoid?
Lateral flexion of neck, rotates chin superiorly
Together: flex neck and extend at atlanto-occipital joint
What is the nerve supply to sternocleidomastoid and trapezius?
Accessory nerve
What is the function of trapezius?
in terms of the neck
Elevates and rotates scapula - shrug shoulders
What are the boundaries of the anterior triangle of the neck?
Inferior margin of mandible
Anterior margin of SCM
Midline of neck
What are the boundaries of the posterior triangle of the neck?
Posterior margin of SCM
Anterior margin of trapezius
Clavicle
Why are the anatomical triangles of the neck important?
Defining pathology as different structures e.g. LN chains run in the triangles
What are the functions of cervical fascia?
Form natural planes
Allows ease of movement between structure e.g. when swallowing
Contains spread of infection
What does the superficial cervical fascia contain?
What type of connective tissue is it?
Loose CT containing fat, platysma, cutaneous nerves, lymph nodes and superficial blood vessels
What are the layers of deep cervical fascia?
Investing layer
Carotid sheath
Pre-tracheal fascia
Pre-vertebral fascia
What are the two layers of the pre-tracheal fascia?
Muscular and visceral
How can you tell if a swelling in the neck is a goitre?
Will move upon swallowing
What are the complications of a goitre?
Compress trachea: breathlessness and stridor
Compress veins: facial oedema
What is contained in the carotid sheath?
Common carotid artery, internal jugular vein and vagus nerve
What does the pre-vertebral layer surround?
Vertebral column and associated muscles
What is the clinical significance of the retropharyngeal space?
Allows infection to spread into the mediastinum = mediastinitis
Which other space runs into the thorax?
Pre-tracheal space
What fascia splits the retropharyngeal space into two?
What is the posterior area called?
Alar fascia
Danger space
What are the three key branches of the trigeminal nerve?
Ophthalmic, maxillary and mandibular
What cranial nerves are the trigeminal and facial nerve?
Cranial nerve V and cranial nerve VII respectively
What does the trigeminal nerve innervate?
Muscles of mastication
Main sensory to face and scalp
What are the five key branches of the facial nerve?
Temporal, zygomatic, buccal, mandibular, cervical
What does the facial nerve innervate?
Muscles of facial expression
Special sensory to tongue-taste, PSNS to salivary and lacrimal glands
What is the main arterial supply to the face?
Common carotid via internal and external carotid (facial artery)
What is the main venous drainage of the face?
Internal jugular via facial vein
Give examples of the muscles of mastication:
Temporalis
Masseter
Pterygoids (lateral and medial)
Give examples of the muscles of facial expression:
Orbicularis oculi Levator palpebrae superioris Occipitofrontalis Buccinator Zygomaticus Orbicularis oris
What is the danger area of the scalp and what does this mean?
Loose CT, allows spread of infection to meninges
What is the arterial supply to the scalp? (broad)
External carotid and ophthalmic arteries
What is the nerve supply to the scalp? (broad)
Trigeminal and cervical nerves
Why do scalp lacerations bleed profusely?
Pull of occipitofrontalis prevents closure of bleeding vessels and skin
Vasoconstriction prevented by adherence of blood vessels to dense CT
Many anastomoses
What is the clinical significance of the path of the facial nerve?
Passes through parotid gland where it can be damaged e.g. tumour or surgery
