General Organisation Flashcards
Where is the neck located?
Extends from the lower margin of the mandible to the suprasternal notch of manubrium and the upper border of the clavicle.
How are structures in the neck compartmentalised?
By layers of cervical fascia:
-
ONE layer of superficial cervical fascia
- loose connective tissue containing adipose
-
THREE deep cervical fascial layers:
- Investing layer (most superficial)
- Pretracheal fascia
- Prevertebral fascia (most deep)
What structures lie in the superficial fascia?
- external jugular vein
- anterior jugular vein
- cutaneous nerves
- superfical lymph nodes
- platysma
Describe the investing layer
- Most superficial of the deep fascia
- Surrounds entire neck
- Encloses the sternocleidomastoid muscle and trapezius
- Encloses submandibular and parotid salivary glands
What are the superior, inferior, anterior and posterior attachments of the investing layer?
- Superior:
- lower border of mandible
- mastoid process
- external occipital protuberance
- Inferior
- upper border of manubrium
- upper surface of the clavicle
- acromion and spine of scapula
- Anteriorly
- hyoid bone
- Posterior
- spinous process of vertebrae
- ligamentum nuchae
Describe the pretracheal fascia
- anterior neck
- attaches to the hyoid bone superiorly and anteriorly
- inferiorly extends into the thorax to join fibrous pericardium
Has a muscular and visceral layer;
- muscular encloses infrahyoid muscles
- visceral encloses thyroid gland, trachea and oesophagus
Where is the buccopharyngeal fascia located?
Posterior to the oesophagus, blending with the pretracheal fascia. Runs from the base of the skull superiorly to the diaphragm inferiorly.
Where is the carotid sheath located?
Base of the skull through the root of the neck to the arch of the aorta.
What does the carotid sheath contain?
- Common carotid artery
- Internal jugular vein
- Cranial nerve (CN)
- Vagus nerve (CN X)
Where is the prevertebral fascia located?
Surrounding the vertebral column.
Attachments:
- Superior - base of skull
- Anterior - transverse processes and vertebral bodies of the vertebral column
- Posterior - nuchal ligament of vertebral column
- Inferior - 3rd thoracic vertebrae
Extends laterally as the axillary sheath surrounding the axillary vessels and the brachial plexus running into the upper limb
What is the clinical correlation between deep cervical fasciae and infection?
Layers of deep cervical fascia form natural cleavage planes allowing structures to move and pass over one another with ease. These are useful during surgery as they allow for easy separation of the layers but determine the direction and extent to which any infection occurring in the neck will spread.
Where do infections of deep neck spaces normally arise from?
Infections of:
- teeth
- tissues of the pharynx
- sinus
- middle ear
Infections of deep neck spaces are rare but lethal
Where is the retropharyngeal space located?
A deep neck space found between the prevertebral fascia and the buccopharyngeal fascia
What are the sources of a retropharyngeal infection?
Usually secondary to an upper respiratory tract infection (nasal cavity, nasopharynx and oropharynx).
- commonly seen in children under the age of 5
- can develop into an abscess
What are the signs and symptoms of a retropharyngeal abscess?
- bulge when inspection oropharynx
- sore throat
- difficulty swallowing (dysphagia)
- stridor
- reluctance to move neck
- fever
Important to recognise and treat early as high morbidity and mortality
What is dysphagia?
Difficultly swallowing
What is stridor?
High pitched wheezing sound caused by disrupted airflow. Also known as musical breathing or extrathoracic airway obstruction.
What is the difference between morbidity and mortality?
Morbitity = illness
Mortality = death
In what direction does a goitre normally grow?
Retrosternally (behind the sternum) as the pretracheal fascia extends into the thorax.
What are the symtoms of an enlarged retrosternal goitre?
- Breathlessness and Stridor
- due to compression of the trachea
- Facial oedma
- due to compression of venous drainage from the head and neck
What are the two broad groups of the muscles of the head and neck?
- Muscles of facial expression
- normally dilators and sphincters, apart from buccinator
- attaches to bone or skin/fascia
- Muscles of mastication
- open or close the jaw
- act on the temporomandibular joint
What are the branches of the Facial Nerve?
FIVE extra-cranial branches (terminal)
- Temporal
- Zygomatic
- Buccal
- Mandibular
- Cervical
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What are the key branches of the trigeminal nerve (CN V) ?
- Opthalmic Division (Va)
- Maxillary Division (Vb)
- Mandibular Division (Vc)
CN V is the main sensory nerve of face and scalp and motor to the muscles of mastication.
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Action, innervation and examination of lateral pterygoids
Action:
- Protrudes mandible
- Opens jaw
- Contralateral excursion (jaw left to right)
Innervation:
- Mandibular branch of trigeminal nerve
Examination:
- Open mouth against resistance
- Move jaw side to side
Action, innervation and examination of medial pterygoids
Action:
- Elevation
- Contralateral excursion
Innervation:
- Mandibular branch of trigeminal nerve
Examination:
- Open mouth against resistance
- move jaw side to side
Action, innervation and examination of masster muscle
Action:
- Elevates mandible (stronger action than medial pterygoid)
Innervation:
- Mandibular branch of trigeminal nerve
Examination:
- Palpation during jaw clench
Action, innervation and examination of temporalis
Action:
- Elevates of retrudes manidble
Innervation:
- Mandibular branch of trigeminal
Examination:
- Palpation during jaw clench
Describe suprahyoid muscles
Act to elevate the hyoid bone and depress the mandible. Innervated by branches of the trigeminal nerve and hypoglossal nerve. Found superior to the hyoid bone.
Describe the infrahyoid muscles
Four muscles situated below the hyoid bone. Supplied by cervical nerves (C1-3)
Superficial layer:
- Omohyoid
- Sternohyoid
Deep layer:
- Sternothyroid
- Thyrohyoid
Either depress hyoid bone or thyroid cartilage
Orbicularis Oculi: action, innervation and examination
Action: orbital region uses to consciously close the eye, palpebral region (found in eyelid) used for unconscious light closure in blinking and sleep.
Innervation: Temporal and zygomatic branches of facial nerve
Examination: Close eyes and resist opening
Levator Palpebrae Superioris: action, innervation and examination
Action: elevates upper eyelid
Innervation: oculomotor nerve
Examination: inspection of eyes for ptosis
What is ptosis?
Drooping or falling of upper eyelid
Occipitofrontalis: action, innervation and examination
Action: elevates eyebrows
Innervation: Frontal belly = temporal branch of facial nerve, Occipital belly = posterior auricular branch of facial nerve
Examination: elevate eyebrows against resistance
What are the layers of the scalp?
S: skin
C: (dense) connective tissue
A: aponeurosis of occipitofrontalis
L: loose connective tissue
P: pericranium
Dilator muscles of the lips: action, innervation and examination
Action: separates the lips
Innervation: Buccal and mandibular branches of facial nerve
Examination: Not individually examined
Buccinator: action, innervation and examination
Action: flattens cheek, holds cheek close to teeth when chewing preventing food from pooling between cheek and gums.
Innervation: Buccal branch of facial nerve
Examination: Blow out cheeks and resist expulsion of air
What are the scalene muscles?
Accessory muscles of respiration. Found within the neck and form the floor of the posterior triangle.
What are the borders of the anterior triangle of the neck?
Superiorly - inferior border of mandible
Medially - sagittal line down the middle of the neck
Lateral - anterior border of sternocleidomastoid
