General Organisation Of The Head And Neck Flashcards
What are the two parts the skull can be split into?
The neurocranium which covers the brain and the viscrocranium that covers the head and neck structures
What are the infrahyoid muscles?
A series of strap like muscles that are running inferiorly from the hyoid bone,
Where can you find the hyoid bone?
Is a u shaped structure that is found at the base of the mandible
How can the platysma muscle be described?
A broad, sheet like muscle that is found lying anterolateral in the neck, that is very superfical, immeadalty below the skin and is found within the superficial fascia
What are the actions of the platysma?
Draws the corners of the mouth inferiorly, and draws the skin of the neck superiorly if the teeth are clenched
What is the nerve supply of the platysma?
The facial nerve (cervical branch)
What is the origin and insertion of the sternocleiodmastoid?
Orignates at the mastoid proccess and then goes to the clavicle or sternum
What are the actions of the sternocleidomastoid?
Unilaterally is involved in the ateral flexion of the neck and rotates the chin superiolry, and bilaterally is involved in flexion of the next, extension of the joint between the base of the skull and the first cervical vertebrae
What is the nerve supply of the sternocleiodmastoid?
The accessory nerve CN XI
What are the actions of the trapezius?
Elevates and rotates the scapulae in order to shurg the sholuders, and the superior border becomes visible when the shoulders are shrugged against resistance
What is the nerve supply of the trapezius?
The accessory nerve Cranial nerve XI
What are the borders of the anterior triangle of the neck?
The superior border is the inferior border of the manible, laterally is bordered by the medial border of the sternocleiodmastoid and medially by a imagninary saggital line down the midline of the body
What does the anterior triangle of the neck contain?
The suprhyoid muscles and the infrahyoid muscle,s and the common cartoid artery and the internal jugular vein, and the cranila nerves that include the facial nerve, the gloospharyngel nerve, the vagus nerve the accessory and the hypoglossal nerves
What are the further triangles that the anterior triangle of the neck can be split into?
The submental triangle, the carotid triangle, the submandibular triangle and the muscular triangle
What are the borders of the posterior triangle of the neck?
Anterior is the posterior border of the sternocleiodmastoid, the posterior is the anterior border of the trapezus muscle and the inferior border is the midlle 1/3 of the clavicle
What is contained in the posterior triangle of the neck?
The trunks of the brachial plexus and also contains the accessory nerve
What are the two MAIN layers of fascia found within the neck?
The superficial cervical fascia and the deep cervical fascia
What are some of the features of the superficial cercival fascia?
Is loose connective tissue, contains fat the platysma, and the cutaneous nerves the lymph nodes and the superficial blood vessels
What are the layers of the deep cervial fascia?
The investing layer, the cartoid sheath, the prevertebral fascial layer and the pretracheal layer
What are some of the features of the investing layer of the fascia?
Splits to envelop the sternocloidmastoid and the trapezius msucles.
What are the contetns of the carotoid sheath?
The cervical lymph nodes, the vagus nerve, the common cartoid artery and the internal jugular vein
What are the two groups that the pretracheal fascaia can be split into?
The visercal that encloses the thyoid gland and the trachea and the osephagus and the muscular layer that encloses the infrahyoid muscles
What is the bucopharygeal fascia?
Is a thickened layer of the pretracheal layer of fascia
What is the clincal signifance of the retropharyngeal space?
Infection can erode through the prevertebral fascia and the retropharngeal space drains into the thorax and then infection can spread into the middle mediastinum, and an abseccess in thi are can result in neck stiffness and stirodor, and difficulty swallowing as well as a sore throat
What are some of the features of the prevertebral fascial layer?
Attaches t the base of skull, and contains the vertebral column and the associated muscles (the pre and paravertebral muscles)
What are the two main groups of muscles that are found in the skull?
The muscles of mastication (which act to open and close the jaw) and the muscles of facial expression (which act as dilators or spinchters)
What innervates the muscles of facial expression?
The cranial nerve VII (the facial nerve)
What innervates the muscles of mastication?
Cranila nerve V the trigemnial?
What is the action of the orbicularis occuli?
Has a outer oribital and a inner palpral part, palepral part is involved in the gentle closure of the eyelid whereas the orbital portion is involved in closing the eyelid more forcefully
What is the action of the corrugator cuperciliar
Acts to draw the eyebrows together and is involved in the creaiton of wrinkles.
What are the actions of the ansalis?
The tranverse part compressess the nares and the motor part opens the nares
What is the action of the procerus?
Pulls the eyebrowns downwards and produces tranverse wrinkles over the node,
What is the action of the orbicularis oris?
Purses the lips
What is the action of the buccinator?
Pulls the cheek inwards towards the teeth preventing the acculumation of food in that area
What are the actions of the massesster??
Elevates the manible and closes the mouth
What are the actions of the temporalsi>
Eleveates the manible and closes the mouth, and retracts the manible pulling the jaw posteriorly
What is the action of the medial pterygoid?
Elevates the manidble and closes the mouth
What is the action of the lateral pterygoid?
Protacts the manible and pushes the jaw forwards
What are the three key branches of the trigeminal nerve?
The ophthalmic branch, the maxillary branch and the mandibular branch (that provides motor innervation to the muscles of mastication)
What are the five key terminal branches of the facial nerve?
Temproal braches,zyogmatic branches, the buccinator brahces and the marginal muchiator brach and the cervical branch to the platymsa
What is the gland that the facial nerve has a important relationship with?
The partoid gland, as it runs through the partoid gland and therefore can be damaged in pathology of this gland
What are the important blood vessels of the head and neck?
The common cartoid artery gives supply via its terminal branches, and the external carotid artoid and the internal aare both involved in supply, and the internla jugular vein, is reduces venous drainage to the face
What are the important layers of tissue in the scalp?
The skin, tthe connective tissue, the epicranial aponeuosis and the loose arelar tissue and the perrcarnium
What is the epicranial aponeurosis?
It is convergance for muscle bellies from the forehead and the occipit, and from the temporal bones on each side
What is the pericrnaium?
A dense layer of connective tissue that involves the external periosteum of the neurocranium
What is the loose areolar tissue layer of the scalp?
A sponge like layer that may distend wiht fluid as a result of injury or infecction and allows free movemnet of the scalp proper
What is the scalp proper?
The skin, the connective tissue and the epicranial aponeurosis
Why do scalp wounds tend to gape widley?
The skin has no deep facia and the subcutanous tissue if
How do wrinkles occur in the skin?
Perpindcicular to the direction of the facial mucle fibres and skin incisions perpindicular to these heal with minoor carign
What is the most important structure in determining the severity of a scalp wound?
The epicranial aponeurosis, because of the strength of this structure superficial skin wounds do not gape, and deep skin wounds will gape when the epicranial aponeurosis is ruptured
What are some of the features of infection within the scalp?
Loose areloar connective tissue is a danger area because blood and pus spreads into it, and the infection can pass into the cranial cavity through the emissary veins and reach structures such as the meniges, and can reacg eyelids or node, and occuptal frontalis
Where can ateries be found in the scalp?
They course within layer 2 of the scalp, and this is the subctuneous tissue between the skin and the epicranial aponeurosi,.
Where is the aterial supply of the scalp from?
The external cartoid arteries, through the occipatla posterior auricular and the superifical temproal ateries.
What are some of the features of the nerves of the scalp?
Temporal branches of the frontal nerve and the opthalmic branch of the trigeminal nerve, and surpa orbital may be involed in the innervation of the scalp, and syogmatic is also inolve in the innervation of the scap, and the auriclomoid nerve and the greate aricular and lesser occiptal nerve
What is the difference between the innervation of the scalp posteiror and anteiror to the auricles?
Innervation of the scalp anterior to the auricles is by all 3 divisions of the trigeminal nerve, whereas posterior to the auricles the nerval supply is from the spinal sutanous nerves
