Surface Anatomy of the Neck Flashcards
What are the four fascial layers in the neck
- Investing (superficial) fascia
- pretracheal fascia
- carotid sheath
- prevertebral fasciae
“True” Retropharyngeal Space
permits movement during swallowing of pharynx, oesophagus, trachea and larynx
Danger space
major pathway for the spread of infection to mediastinum
Retropharyngeal abscesses
– Nasopharynx, paranasal sinuses or middle ear infections
what are the borders of the posterior triangle
anterior: posterior border of the SCM
posterior: anterior border of the trapezius muscle
inferior: middle 1/3 of the clavicle
what are the borders of the anterior triangle
superiorly: inferior border of the handle
laterally: anterior border of SCM
Medially: sagittal line down the midline of the neck
What do you need to consider when identifying neck lumps
Location – Anterior triangle – Posterior triangle – Midline Tenderness Heat/Inflammation Size/Depth Pulsatile Solitary or multiple lumps Movement - Swallowing - Sticking out tongue
THYROID CARTILAGE
- there are two lamina the lesser and greater horns
- there are laryngeal prominence (composed of the fusion of the inferior 2/3 of two lamina - ADAMS APPLE)
- thyroid cartilage articulates with the cricoid cartilage (rotation and gliding thyroid cartilage which changes the length and sound of the vocal cords)
BRACHIOCEPHALIC TRUNK
anteriorly covered by the right sternothyoid and sternothyroid muscles
- passes superolaterally to the right and divides:
right common carotid and right subclavian arteries which run posterior to the sternoclavicular joint
SUBCLAVIAN ARTERY
Passes Rib 1 on way to upper limb
3 parts, according to the subclavian artery
1st part of the subclavian artery
– Vertebral artery
– Thyrocervical trunk
– Internal thoracic artery
2nd part of the subclavian artery
– Costocervical trunk
3rd part of the subclavian artery
– Dorsal scapular artery
COMMON CAROTID ARTERY
Bifurcates at the level of superior border of thyroid cartilage
– Internal carotid artery
– External carotid artery
Superiorly covered by muscles
Distally exposed allowing palpation of pulse
– Normally internal carotid artery
CAROTID BIFURCATION
- Level of the superior border of the thyroid cartilage
- External carotid artery
- Internal carotid artery
– Dilatation of proximal internal carotid artery
CAROTID BODY & CAROTID SINUS - Nerve supply
- afferent glossopharyngeal (carotid sinus nerve)
- efferent vagus nerve
Carotid Sinus receptors
Baroreceptor
– Reacts to change in arterial blood pressure
Carotid Body receptors
Chemoreceptor
– Monitors the partial pressure of CO2
INTERNAL CAROTID ARTERY
covered by the carotid sheath , this sheath carries the:
- internal jugular
- internal carotid
- vagus nerve
supplies the intracranial structures
EXTERNAL CAROTID ARTERY
Some Anatomists Like Freaking Out Poor Medical Students
Superior thyroid artery Ascending pharyngeal artery Lingual artery Facial artery Occipital artery Posterior auricular artery Maxillary artery Superficial temporal artery
venous drainage of the cervical veins
– External jugular vein – Anterior jugular vein – Vertebralvein
venous drainage fo the cranial veins
– Cerebralveins
– Dural venous sinuses – Diplopic veins
– Emissary veins
CRANIAL VEINS
Drained by – Dural venous sinus • Superior sagittal sinus • Inferior sagittal sinus • Sinus rectus – Sigmoid sinus • Becomes internal jugular vein
INTERNAL JUGULAR VEIN
Drains intracranial structures, superficial parts of face and neck
Within the carotid sheath
– Vagus and internal carotid artery
Initially lies posterior to the internal carotid artery, moves laterally then anterior of the common carotid
Jugular Venous Pulse Wave is visible along the trajectory of the IJV
Central Venous Access or Central Venous Catheterisation
Most commonly inserted in the internal jugular vein (sometimes subclavian) Measure central venous pressure (CVP) – Normal CVP is <8 cm H2O Administration of fluids, medications Complications – Pneumothorax – Puncture of subclavian artery – Nerve injury
what is the risk if you catheterise through the external jugular vein
air embolism
EXTERNAL JUGULAR VEIN
Descends from the angle of the mandible to the middle of the clavicle
- Crosses the SCM obliquely, deep to the platysma, and enters the antero- inferior part of the posterior triange.
- Pierces the investing fascia at the posterior border of the SCM.
- Descends and terminates in the subclavian vein.
- Drains most of the scalp and side of the face.
what is the external jugular veins formed by
– Posterior division of
the retromandibular vein – Posterior auricular vein
ANTERIOR JUGULAR VEIN
Inferior to the hyoid bone • Drains into external jugular or subclavian veins • Anterior jugular veins of both sides join • Jugular venous arch
NERVES IN THE NECK
Cutaneous branches of the cervical plexus
Erb's point – four cutaneous branches become superficial – Lesser occipital – Greatauricular nerve – Transverse cervical – Supraclavicular
• Accessory nerve
– Motor control of
trapezius and SCM
– Passes across the posterior triangle
LYMPH NODES IN THE NECK
- No lymph nodes in the scalp or face
* Except parotid/buccal region