Blood Vessels Of The Head And Neck Flashcards
Origin of the right common carotid artery
Arch of aorta > brachiocephalic trunk > right common carotid artery
Origin of the left common carotid artery
Direct branch from the arch of aorta
What do the common carotid arteries bifurcate into?
Internal + external carotid artery
At what point do the common carotid arteries bifurcate?
C4
What is the bifurcation of common carotid artery a common site for?
Atherosclerotic plaque due to it being a ‘site of turbulence’
Where is the carotid sinus located?
Proximal point of the internal carotid artery with a bulbous appearance
Where is the carotid body located?
In adventitia of carotid artery bifurcation
Function of the carotid sinus
Monitors blood pressure using baroreceptors
Function of carotid body
Monitors blood pO2 using chemoreceptors
What is a carotid sinus massage?
stimulates the baroreceptors and slows heart rate
What is a carotid ultrasound (doppler) scan used for?
- to visualise + measure blood flow
- identify stenosis
How many branches does the external carotid artery have?
8
Where does the external carotid artery terminate?
As the superficial temporal artery + maxillary artery
What is arteritis?
Inflammatory of the walls of arteries
What is temporal arteritis?
What does it have a high risk of?
- inflammation of arteries by temples
- losing vision
Name three branches of the maxillary artery
- middle meingeal artery
- sphenopalatine artery
- greater palatine artery
Where does the sphenopalatine artery supply?
Nasal cavity
What are the branches of the external carotid artery
Some Anatomists Like Freaking Out Poor Medical Students
Superior thyroid artery
Ascending pharyngeal
Lingual
Facial
Occipital
Posterior auricular
Maxillary
Superficial temporal
Role of the superior thyroid artery
Supplies thyroid gland
Role of the lingual artery
Supplies tongue
What branches of the external carotid artery supply the back of the scalp?
Occipital artery
Posterior auricular artery
What is the route of the internal carotid artery?
- ascends neck in carotid sheath
- runs through petrous bone via carotid canal
- enters cavernous sinus + exits
- gives branches
What are the branches of the internal carotid artery?
- ophthalmic artery
- middle cerebral artery
- anterior cerebral artery
Where do the vertebral arteries branches from?
Subclavian artery
What is the route of the vertebral arteries?
- ascends up neck in tranasversa foramina C6-C1
- pierces posterior atlanto-occipital membrane + enter intracranially via foramen magnum
- right + left vertebral artery join to form basilar artery
What are the boundaries of the carotid triangle?
- superior: posterior belly of digastric
- medial: superior belly of omohyoid
- lateral: sternocleidomastoid
What group of muscles does digastric belong to?
Suprahyoid muscles
What group of muscles of omohyoid belong to?
Infrahyoid muscles
What is readily accessible through the carotid triangle?
Carotid sheath e.g. surgical access
What is a carotid endartectomy?
- incision into neck in carotid triangle
- common + internal carotid artery identified and incised
- removal of atherosclerotic plaque
What are the importances of the carotid triangle?/
- site of bifurcation of CCA
- surgical access to carotid sheath
- palpating of carotid puse
- carotid sinus massage
What does the external jugular vein drain into?
Subclavian vein
What drains into the external jugular vein?
Veins draining scalp + deep face
Location of the external jugular vein
- in superficial cervical fascia
- superficial to SCM
- in roof of posterior triangle
Route of the internal jugular vein
Descends length of neck in carotid sheath deep to the SCM
Route of the internal jugular vein to the heart
IJV > subclavian vein > brachiocephalic vein > superior vena cava > right atrium
How would you measure jugular venous pressure using venous pulsation from IJV?
- lay patient at 30-45°
- examination of venous pulsation from right IJV
- vertical heigh of pulsations seen - indicates pressure in right atrium
Outline accessing the internal jugular vein with a central line
- under ultrasound guidance
- point of access between two heads of SCM
- used for continuous monitoring of central venous pressure + drug infusions
How can orbital infections spread intracranially?
- the ophthalmic veins drain the structures of the orbit + drain mostly via the facial vein
- the ophthalmic veins also communicate with the cavernous sinus
- as these veins are valveless, blood can pass in either direction > infection can spread
How do infections of central face/nasal cavity spread intracranially?
- facial vein drains deep structure of the central face e.g. nasal cavity
- communicate with pterygoid venous plexus + cavernous sinus
- route for infection of central face/nasal cavity to spread intracranially
What artery is formed by the convergence of the vertebral arteries?
Basilar artery
Presentation of temporal arteritis
Blurry vision
Tenderness over temple
Headache
Tongue +jaw claudation on mastication
Diplopia
Blindness
Management of temporal cell arteritis
Steroids
To reduce inflammation
Why is the internal jugular vein used for central line access over the subclavian vein?
Higher risk of causing pneumothorax if using subclavian vein
