(1.1) Muscles, Fascia, Planes and Regions Flashcards
What structures are enclosed by the Pretracheal layer?
Muscular part encloses Infrahyoid muscles
Visceral art encloses Thyroid gland + Trachea + Oesophagus (anterior to posterior)
What are fasica? What are their roles in the head and neck?
Fascia = connective tissues that separate organs and anchor them to the body
Compartmental
Allows structures to glide over each other
Determines spread of infections/metastasis
What are the terminates of the prevertebral layer of the deep cervical fascia? What structures does it enclose?
Superiorly attaches to the base of cranium
Inferiorly attaches to T3
Laterally becomes Axillary Sheath
Encloses the vertebrae + the muscles associate with them
What is the Axillary Sheath?
A continuation of Prevertebral layer, enclosing the first portion of the Axillary Artery and Vein and the Brachial Plexus
Describe and draw a simple diagram of the layers in the neck.
Skin
Superficial cervical facia: containing Subcutaneous fat + neurovasculatres + Platysma (anterior only)
Deep cervical fascia
- Investing: invests SMC & Trapezius
- Pretracheal: from Hyoid bone and blends with Pericardium
- Muscular part: encloses Infrahyoid muscles
- Visceral part: encloses Thyroid gland, Trachea, Oesophagus
- Prevertebral Layers: surrounds vertebral column and associated structures
- anteriorly: attached to transverse process and vertebral bodies of the vertebral column
- posteriorly - attached to ligamentum nuchae at T3
- becomes Axillary Sheath inferiorly, surrounding first portion of Brachial Plexus & Axillary A and V
- Carotid Sheath: fusion of the above three deep fascia
- contains Common Carotid A (medially) + Internal Jugular V (laterally) + Vagus V (dorsally)
https://cfaascience.files.wordpress.com/2010/09/neckfascia.jpg
What is the embryonic origin of Facial Nerve? Hence what muscles does it innervate?
2nd Pharyngeal arch
Innervate muscles of facial expression
What is the embryonic origin of muscles of facial expression? Hence what nerve are they innervated by?
2nd Pharyngeal arch
Innervated by facial nerve
What is the major route of the spread of infection from the neck to the diaphragm? What may be the consequences of if pus accumulates?
- Within the Retropharyngeal space = between the visceral part of the Pretracheal layer and Prevertebral layer
- Abscess -> Dysphagia / Dysphonia (inability to use vocal cords) / Dysarthria (dysfunction of the muscles used to speak)
What may be the consequences due to paralysis of Orbicularis Oculi?
Exposure Keratitis = dried out cornea
Ectropion = ulcerated corneal surface, unable to close the eyelids -> lacrimal fluid isn’t spread over the cornea, to remove debis
A gentleman came in to complain that he hasn’t been able to blow his flute after his surgery on parotid gland, what has happened here?
Surgical accidentally damage the facial nerve -> denervation to Buccinator
What muscle is responsible for wrinkling the forehead + raising the eyebrows?
Occipitofrontalis
What is the difference between Facial paralysis and Bell’s palsy?
- Facial paralysis: known causes + doesn’t recover
- Bell’s palsy = idiopathic + recovers
Where are the facial nerve most at risk of damage?
- Middle ear pathology
- Parotid gland
- Stylomastoid foramen of Temporal bone where it leaves Facial Canal
What is the embryonic origin of muscles of facial mastication? Hence what nerve are they innervated by?
1st Pharyngeal arch
innervated by Mandibular division of Trigenminal nerve
What action does the Platysma produce? What is its innervation?
- Depresses Mandible
- Innervated by branches of Facial Nerve
What actions does the Trapezius produce? What is its innervation?
- Superior fibres: rotate Scapula for arm abduction >90
- Middle fibres: retract Scapula
- Lower fibres: depress Scapula
- Innervated by Accessory Nerve (CN XI)
What actions does the Sternocleidomastoid produce? What is its innervation?
- Bilaterally: elevate the head
- Unilaterally: rotates the head medially
- Innervated by Accessory Nerve (CN XI)
What are the two attachments of the distal Sternocleidomastoid?
- Medial 1/3 Clavicle
- Sternum
What are the four Suprahyoid muscles? What is their action?
- Geniohyoid
- Mylohyoid
- Stylohyoid
- Digastric - 2 bellies, anterior & posterior
- They elevate Hyoid bone & Larynx to initiate swallowing
What are the four Infrahyoid muscles? What is their action?
- Sternohyoid (superficially)
- Omohyoid (superficially) - 2 bellies, superior & inferior
- Thyrohyoid (deep)
- Sternothyroid (deep)
- They depress Hyoid bone & Larynx during swallowing
What are the boundaries of Posterior Triangle?
What 2 further triangles can the Posterior Triangle be divided into?
- Inferiorly: middle 1/3 of Clavicle
- Medially: lateral border of Sternocleidomastoid
- Laterally: medial border of Trapezius
- Occipital Triangle
- Subclavian (Omoclavicualr) Triangle
http: //teachmeanatomy.info/neck/areas/posterior-triangle/
What are the boundaries of Anterior Triangle?
What further four triangles can the Anterior Triangle be devided into?
- Superiorly: Mandible
- Laterally: medial border of Sternocleidomastoid
- Medially: imaginary midline
- Carotid Triangle
- Submandibular (Diagastric) Triangle
- Submental Triangle
- Muscular (Omotracheal) Triangle
http: //teachmeanatomy.info/neck/areas/anterior-triangle/
What structures are found in the Submental Triangle?
- Submental lymph nodes
What structures are found in the Submandibular Triangle?
- Submandibular gland & lymph nodes
- Parts of Facial artery & vein
- Hypoglossal (CN XII) & br. of Inferior Alveolar (CN Viii) nerves
What structures are found in the Muscular Triangle?
- Thyroid & Parathyroid glands
- Sternohyoid muscle
- Omohyoid muscle
- Thyrohyoid muscle
- Sternothyroid muscle
What structures are found in the Carotid Triangle?
- Carotid Sheath (Common Carotid A, Internal Jugular V, Vagus N & SNS fibres)
- Thyroid gland
What structures are found in the Carotid Sheath? Describe their positions of each other.
- Common Carotid Artery medially (bifurcates, only ICA within the Sheath above C4)
- Internal Jugular Vein laterally
- Vagus Nerve dorsally
- Carotid Sinus & Body
- SNS fibres surrounding Carotid A
Where can the Carotid pulse be felt?
Larynx & Middle 1/3 of front edge of Sternocleidomastoid
What structures can be found in the Occipital Triangle?
- Trunks of Brachial Plexus
- Accessory Nerve (CN XI)
How is the Jugular Venous Pressure measured? What is its significance? How to interpret it?
- Patient lies at 45 angle, looking to the left
- Indirect measurement of the pressure in right atrium e.g. systemic venous pressure
- Normally pulsation
What structures can be found in the Subclavian Triangle?
- Subclavian A & V
- Supraclavicular lymph nodes
- Suprascapular Artery
How may a person with damaged Sternocleidomastoid present with?
Torticollis = head tilt & rotated to the side that isn’t damaged
A 5 year old boy has been diagnosed with Quinsy, from where may an infection spread?
Quinsy = peritonsillar abscess
Through Parapharyngeal space -> affecting contents within Carotid Sheath
How can infections in the neck spread to the thorax?
- Draining into the retropharyngeal space which extends to the diaphragm
- Down the carotid sheaths as they extend from the base of the skull to the thorax
How may an infection in the superficial skin abscess spread?
Not further back into the neck as the Investing layer prevents it
How may an infection posterior to the Prevertebral fascia spread?
Perforates through Prevertebral fascia into the Retropharyngeal space and spread down the diaphragm
How may an infection between the Visceral part of Pretracheal and the Prevertebral fascia spread?
Infection spreads inferiorly to the anterior to Pericardium (e.g. anterior Mediasternum)
