Carotid Triangle & Neurovascular Structures Flashcards
What is the Carotid Triangle & what is it bounded by?
a VASCULAR AREA bounded by:
- superior omohyoid
- posterior digastric
- anterior border of SCM
What does the Carotid Triangle contain?
- thyroid gland
- larynx
- pharynx
- carotid sheath (& contents)
- branches of cervical plexus
- superior root of the ansa cervicalis
- deep cervical lymph nodes
- parts of CN XI & XII
Where does the right common carotid artery ascend from?
Branch of the braciocephalic trunk
Where does the left common carotid artery ascend from?
direct branch from the arch of aorta
what artery supplies the brain?
the internal carotid artery
what is the carotid sinus?
an enlargement/dilation at bifurcation of common carotid artery containing baroreceptors/pressoreceptors in wall of ICA
why is the carotid sinus important?
- important in monitoring blood pressure
- baroreceptors are sensitive to stretch
- helps keep blood pressure within homeostatic values
what is the carotid sinus innervated by?
- CN IX (glossopharyngeal nerve) via carotid sinus nerve
- CN X
What is the carotid body?
A small organ (2-5mm) which houses chemoreceptors located at bifurcation of CCA near the carotid sinus
Where does the carotid body lie?
Lies in a septum on the medial side of the bifurcation of the common carotid artery
What is the function of the carotid body?
- important in monitoring blood O2, CO2 and pH (& temperature)
- responds in emergency situations by increasing respiration, blood pressure & cardiac rate
what is the carotid body innervated by?
CNIX (glossopharyngeal) via carotid sinus nerve & CNX
where does the internal carotid artery supply?
main artery of the brain & structures in the orbits
where does the external carotid artery supply?
supplies most structures external to the cranium
- EXCEPT the orbit & part of forehead
what are the anterior branches of the external carotid artery?
- superior thyroid
- lingual
- facial
what are the posterior branches of the external carotid artery?
- occipital
- posterior auricular
what is the medial branch of the external carotid artery?
ascending pharyngeal artery
what are the terminal branches of the external carotid artery?
- superficial temporal
- maxillary
what artery does the middle meningeal artery branch off of?
the maxillary artery
what is the largest vein of the neck? what structures does it drain?
the Internal Jugular Vein drains:
- brain
- skull
- face
- parts of neck
what vein is a continuation of the sigmoid sinus?
the internal jugular vein
where is the internal jugular vein located?
- exits skull via the jugular foramen
- enters the carotid sheathe
- runs lateral to the common carotid artery
what veins drain into the internal jugular vein?
- inferior petrosal sinus
- pharyngeal
- occipital
- facial
- lingual
- superior thyroid
what is the function of the inferior bulb & valve of the IJV?
permits blood flow towards the heart while preventing backflow into the vein (might occur if inverted)
what muscle runs directly across the IJV?
the omohyoid muscle
what structures does the external jugular vein drain?
mainly drains the scalp & face
what veins drain directly into the external jugular vein?
- posterior external jugular
- transverse cervical
- suprascapular
- anterior jugular
where do anterior jugular veins arise?
near the hyoid bone & run on either side of the midline through subcutaneous tissue
what nerve emerges through the stylomastoid foramen?
CNVII & gives off the posterior auricular nerve
what does the parotid plexus give rise to?
- temporal nerve
- zygomatic nerve
- buccal nerve
- marginal mandibular
- cervical
what does the cervical branch of CNVII innervate?
platysma muscle
what nerve innervates the digastric muscle?
digastric branch of CNVII
what nerve supplies the stylohyoid muscle?
CNVII
what branches does CNX (vagus) give rise to?
- pharyngeal
- laryngeal
- cardiac branches
what are symptoms of damage to CNX laryngeal branches?
- hoarseness of voice
- aphonia
what does the transverse cervical nerve innervate?
cutaneous innervation over SCM & anterior triangle
what does the ansa cervicalis innervate?
infrahyoid muscles
