1 - General Organisation Flashcards
What are the two groups of muscles in the face and what is their nerve supply?
- Muscles of facial expression: the scalp (occipitofrontalis) and muscles of the cheek (buccinators)
- Buccinators keep cheeks taut to keep food in oral cavity and not pooling between cheeks
What are the extra-cranial branches of the facial nerve?
To Zanzibar By Motor Car
(innervates muscles of facial expression)
(nerve travels through substance of parotid gland when leaves skull so nerves and gland closesly related)
What is the nerve supply to the muscles of mastication and what else does this nerve supply?
What nerves supply each sensory part of the face?
What is Bell’s Palsy?
- Most common non-traumatic cause of ipsilateral facial paralysis. Due to inflammation of the facial nerve. Inflammation causes oedema and compression of the nerve as it leaves the skull.
- Drooping face
How may parotid cancer present?
- Weakness of facial muscles on one side with ipsilateral enlargement of the parotid gland.
- Weakness due to infiltration of cancer into facial gland
- Benign parotid pathology (e.g mumps) usually has no facial weakness as nerve not involved
What are the muscles of mastication? (movement of the TM joint)
- Temporalis
- Masseter
- Pterygoids (not palpable)
(all supplied by mandibular division of trigeminal nerve)
What is the action of the muscles of mastication?
- All elevate the mandible apart from one
- Lateral pterygoid assists suprahyoids and gravity to depress the manbile
‘Laaaaaaaateral’
Label the landmarks on this neck.
thyroid, cricoid, and thyroid GLAND now
What are the borders of the posterior and anterior triangle of the neck and why are they important?
- If know which triangle a lump is in can help figure out a cause for the lump based on the anatomy in that triangle
- 2x each triangle
What is the importance of the scalene muscles?
- Floor of posterior triangle
- Brachial plexus and Subclavian vessels pass between anterior and middle scalenes
- Phrenic nerve along anterior scalene before thorax
What are the borders and the importance of the carotid triangle?
Useful for JVP and catheters
Can find carotid sheath here for easy access
Label the cross section of this neck and explain the importance of the 1 superficial and 3 deep fasical compartments.
Why does the neck have fascial compartments?
Allows structures to pass over each other and layers to be separated easily in surgery but determines direction and extent of infection
What is the retropharyngeal space and the importance of it?
- Between pre-vertebral layer and buccopharyngeal fascia
- Can cause mediastinitus if abscess or infection here as can infect fasical plane and track down
- Up to age 3 this space contins lymph nodes to drain nose, oral cavity and upper pharynx
- Usually needed to allow space for pharynx to expand when swallowing
How may a retropharyngeal abscess present?
- Secondary to upper RTI in children under 5 usually
- Visible bulge, sore throat, difficulty swallowing, stridor, reluctance to move neck, high temperature
- High morbidity as risk of mediastinitus
- Differentials: meningitis or mumps
(swelling and irritation (inflammation) of the chest area between the lungs (mediastinum))
What can be some symptoms of a goitre apart from a visible bulge that moves up when swallowing?
- Breathlessness, stridor, facial oedema
- Goitre can be restrosternal and extend into thorax due to pre-tracheal fascia
- Goitre compreses trachea and venous drainage
Where can you palpate the carotid pulse?
What are supra and infrahyoid muscles?
- Stabilise the hyoid bone, also called strap muscles
- Infra supplied by cervical nerves C1-C3
- Supra supplied by cranial nerves
Label this diagram of the neck at the level of the superficial cervical fascia.
What are the actions and innervations of the following muscles:
- Platysma
- Sternocleidomastoid
- Trapezius
- Make sure can recognise muscles on prosection (use google)
- Platysma is cervical branch of facial nerve
- SCM rotates head also
Label the following muscles of facial expression and the action that they have:
- Orbicularis Oculi
- Occipitofrontalis (frontalis and occipitalis)
- Orbicularis Oris
- Orbital part on outside squeezes eye shut forcibly but palpebrl part on inside closes eyelids e.g blinking
- Occipitalis is muscle at back of head joined to frontalis at front by big aponeurosis. Forms layer of the scalp and elevates the eyebrows and wrinkles forehead
- Purses lips
Label the following muscles of facial expression and the action that they have:
- Buccinator
- Dilators of lips (e.g zygomatics and risorius)
- Compresses cheeks against teeth during mastication. Trumpet player contract it
- Risorius pulls corner of mouth laterally so smile and zygomaticus pulls mouth laterally and upwards so teeth smile
What are the muscles of mastication and their actions?
- Medial pterygoid: Elevates mandible and protrudes it
- Lateral pterygoid: Depresses (open) mandible and protrudes it
- Masseter: Elevates (closes) mandible. Palpable on jaw
- Temporalis: Elevates mandible and posterior fibres retract it
ALL INNERVTED BY MANDIBULAR PART OF TRIGEMINAL NERVE (CN V)
What is levator palpebrae superioris?
- Muscle in upper eyelid innervated by CN III
- Elevates the upper eyelid
What is omohyoid?
Has two bellies that are joined by a tendon. Superior belly makes up border of the carotid triangle, along with digastic (posterior belly) and SCM
What are each of the cervical vertebrae important landmarks for?
Identify the omohyoid and digastric muscles on this diagram. Explain where the carotid sheath is and what lies in it.
Talk about location of bundles within as well
- 3 AND 5
- Common carotid artery (up to C4) medially, internal jugular vein laterally, vagus nerve posteriorly
