Major Blood Vessels Flashcards
What forms the borders of the carotid triangle?
Sup = post border of digestric
Lat = medial border SCM
Inf = sup border of omohyoid
Where is the external jugular V with regards to SCM?
Lies over SCM = more superficial
The common carotid and internal jugular V are hidden by what?
SCM
What arises from the brachiocephalic trunk?
Subclavian
Common carotid
When does the common carotid A bifurcate?
- Within the carotid triangle ~C4
- Level of superior border of the thyroid cartilage
Into = internal (no branches) and external (branches) carotid A
Outline the branches of the subclavian A
Vertebral A = supply brain
Thyrocervical trunk = supply shoulder/neck region, thyroid
Inferior thyroid A = inferior part of thyroid gland
Internal thoracic A = supply intercostal
What are the vertebral A?
Arise from subclavian A
Supply intracranial structures
Course via transverse foramen 1-6
Through foramen magnum, join to form basilar A – then join circle of willis
What is the circle of willis?
A circulatory anastomosis that supplies blood to the brain and surrounding structures
How is bifurcation related to carotid artery atheroma?
Common site for atheroma formation due to turbulence = narrowing of artery
Rupture of clot can cause embolus = TIA, stroke
What is the carotid body?
Peripheral chemoreceptors which detect arterial O2
Outside the A
What is the carotid sinus?
Swelling at bifurcation of caratid A
Location of baroreceptors for detecting changes in arterial BP
What does the carotid triangle contain?
Vagus N
Common carotid A
Internal jugular vein
Why is knowing the carotid triangle important?
Surgical approach to carotid arteries/IJV
Access vagus/hypoglossal Ns
Carotid pulse just below bifurcation
Carotid sinus massage = terminate SVT
Discuss the ophthalmic A
Branch of the internal carotid A
Supplies structures within and around the eyeball
Gives off = supratrochlear A, supra-orbital A
What is the mnemonic for branches of the external carotid A and their equivalents?
Some Anatomists Like Freaking Out Poor Medical Students
S = Superior thyroid = supplies superior thyroid
A = Ascending pharyngeal = pharynx
L = Lingual = tongue
F = Facial = structures in face
O = Occipital = structures around eye
P = Posterior auricular = Scalp posterior to auricle
M = Maxillary = (terminal)
S = Superficial temporal = scalp (terminal)
What is the blood supply to the scalp?
Internal carotid = supra-orbital, supratrochlear
External carotid = superficial temporal A, posterior auricular A, occipital A
What A supplies the skull?
Middle meningeal
What causes profuse bleeding from the scalp?
Opposing pull of occiptofrontalis on the epicranial aponeurosis
What are the superficial A of the face?
Transverse facial A (EC)
Angular A (EC)
Lateral nasal A (EC)
Superior & inferior labial A (EC)
Facial A (EC)
Supra-orbital (IC)
Supratrochlear (IC)
What is the kiesselbach area?
Nasal septum
4 A anastomose to form a vascular plexus
Common site for nose bleeds (epistaxis)
Where does the middle meningeal A branch from?
Maxillay A – external carotid A
What does the middle meningeal A branch into?
Anterior branch = lies over the pterion (thin area of the skull, risk of fracture)
Posterior branch
How does the middle meningeal A pass through the skull?
Foramen spinosum
In what layer does the middle meningeal A sit?
Between the skull and dura = supplies both
Rupture = extradural haemorrhage (lens shape)
