1.2 Anterior triangle of neck Flashcards
what does the carotid triangle contains?
common carotid artery (which bifurcates into external and internal carotid arteries), IJV, hypoglossal (XII) and vagus (X) nerves
what are the boundaries of the carotid triangle?
posterior belly of digastric, anterior border of SCM, superior border of omohyoid
what does the muscular triangle contain?
infrahyoid (strap) muscles, the pharynx and the thyroid and parathyroid glands:
what are the boundaries of the muscular triangle
midline of neck (media), superolateral (superior belly of omohyoid), inferolateral (inferior portion of SCM)
what does the submental triangle contain?
submental lymph nodes (filter lymph from the floor of the mouth and parts of the tongue):
what are the boundaries of the submental triangle?
hyoid bone (inferior), anterior belly of digastric (lateral), midline of neck (medial), base (mylohyoid muscle- runs from mandible to hyoid bone)
what does the submandibular triangle contain?
submental lymph nodes (filter lymph from the floor of the mouth and parts of the tongue):, facial vessels
what are the boundaries of the submandibular triangle?
superior (body of the mandible), anterior (anterior belly of digastric), posterior (posterior belly of digastric)
what is the innervation of the infrahyoid (strap) muscles
- Omohyoid, sternohyoid, sternothyroid: Anterior rami of C1-C3 (branch of ansa cervicalis)
- thyrohyoid: anterior ramus of C1 (hypoglossal nerve)
Thyroid surgeries of large goitres:
- to access the thyroid gland, the infrahyoid muscles must be divided (cut) as they lie superficial to the gland
- Must be cut at the _________________because the nerv e supply to these muscles are at the lower end –> avoid cutting the nerves
upper end (closer to the chin)
what is the innervation of the suprahyoid muscles?
- mylohyoid: mylohyoid nerve (branch of inferior alveolar nerve- CN V3)
- anterior belly: mylohyoid nerve (CNV3)
- Posterior belly: facial nerve (CN VII)
carotid sheath is a tubular fascial investment which extends from the cranial base to the root of the neck, surrounding the major vessels in the neck:
• From medial to lateral: common and internal carotid arteries (ECA pierces through sheath) → vagus nerve (CN X) → internal jugular vein (IJV)
• _________ is embedded in the anterior wall, while the ___________ lies posterior to the sheath
Ansa cervicalis;
cervical sympathetic chain
where is the superior loop of ansa cervicalis fibers derived from and what does it supply
C1 fibres (accompanying hypoglossal nerve/CN XII before separating in the carotid triangle) • Supplies superior belly of omohyoid, upper parts of sternothyroid and sternohyoid
where is theinferior superior loop of ansa cervicalis fibers derived from and what does it supply
Derived from C2 – C3 fibres
• Supplies inferior belly of omohyoid, lower parts of sternothyroid and sternohyoid
he common carotid arteries have different origins on the left and right side:
• Left CCA arises directly from the aortic arch (as the 2nd major branch), while the right CCA arises from the brachiocephalic trunk (bifurcates)
• Ascends in the carotid sheath (in carotid triangle) with IJV and vagus nerves (CN X)
• Bifurcates into the external (ECA) and internal (ICA) carotid arteries at the ___________________
upper border of the thyroid cartilage (level of C4)
what are the external carotid artery branches in the neck
Superior thyroid artery Ascending lingual artery Lingual artery Facial artery (tortuous cause in face) Occipital artery Posterior auricular artery Maxillary artery Superficial temporal artery
carotid sinus
- where is it
- what does it do
- slight bulge at bifurcation of CCA and comencement of ICA
- contains baroreceptors (detects pressure changes in blood passing to brain)
- passes to medullary cardiovascular centre
carotid sinus
- where is it
- what does it do
- Structure lying betwee
- Contains chemoreceptors (detect pH changes in blood passing to brain)
- Passes to medullary respiratory centre
where can the carotid pulse be found?
anterior border of the SCM at the level of the superior border of the thyroid cartilage:
what are the tributaries of the IJV
Middle thyroid vein (within the skull; site of IPSS for ACTH levels), Superior thyroid vein Lingual vein Facial vein Pharyngeal vein Inferior petrosal sinus
The IJV is crossed superficially by the_______________ at the upper end:
• Runs downwards deep to the SCM, and posterior to the ICA at the level of C2
• From the level of C4, it lies lateral to the ICA then CCA within the carotid sheath
• Vagus nerve lies deep to and in between the ICA/CCA and IJV in the carotid sheath
spinal accessory nerve (CN XI)
Central line/central venous catheter is a catheter placed into a large vein to administer medications or fluids (cannot be orally administered or would damage a smaller peripheral vein), obtain blood tests, and measure central venous pressure:
• Typically inserted at the right/left IJV or the right/left subclavian veins
• IJV follows a line extending from the inferior aspect of the external acoustic meatus to the sternal end of the clavicle (passing between the ___________________) → landmark for insertion of central line
sternal and clavicular heads of SCM
where are the horizontal groups of lymph nodes (from anterior to posterior)
submental, submandibular, pre-auricular/parotid, mastoid, occipital
where are the superficial vertical lymph nodes?
Extend along the EJV; draining the parotid glands and lower parts of the ear into the deep cervical nodes
where are the deep vertical lymph nodes?
Extend along the IJV from the base of skull to root of neck (drains superficial nodes):
• Jugulo-digastric nodes: along posterior belly of digastric muscle
• Jugulo-omohyoid nodes: at the intermediate tendon of omohyoid
