3.1 Major Blood Vessels of Head and Neck Flashcards
What do the subclavian and common carotid arteries arise from on the right?
Brachiocephalic trunk
Which arteries arise from the subclavian arteries in the base of the neck?
Vertebral
Internal thoracic
Thyrocervical
Does the common carotid artery give off any branches in the neck?
No
It bifurcates to give external and internal carotid arteries
What part of the thyrocervical trunk supplies the neck?
Ascending cervical and transverse cervical
What part of the thyrocervical trunk supplies the shoulder?
Suprascapular
What part of the thyrocervical trunk supplies the lower pole of the thyroid gland?
Inferior thyroid
What is the location of the bifurcation of the common carotid?
Superior border of thyroid cartilage
C4
How can a carotid artery atheroma cause a TIA or stroke?
Atheroma causes narrowing of artery
Rupture of clot can cause an embolus to travel to the brain
What is the carotid sinus and what does it detect?
Swelling at the region of bifurcation that has baroreceptors to detect changes in arterial BP
What does the carotid body detect?
Peripheral chemoreceptors which detect arterial O2
What can be accessed via carotid triangle for surgery?
Carotid arteries
IJV
Vagus nerve
Hypoglossal nerve
How does a carotid sinus massage work?
Apply pressure to terminate a supra ventricular tachycardia
Stimulates vagus to slow down heart
Describe the route of the internal carotid artery
Enters the skull through the carotid canal in petrous part of temporal bone
Turns medially and horizontally
Enters the cranial cavity then makes and S shaped bend
Course through cavernous sinus
Where can the cavernous sinus be found?
On either side of pituitary gland on upper surface of sphenoid
What is in the cavernous sinus?
Internal carotid artery CN III Oculomotor CN IV Trochlear CN VI Abducens CN Va Ophthalmic CN Vb Maxillary
What is the pneumonic to remember the contents of the cavernous sinus?
O TOM CAT
What is the first brach of the internal carotid?
Ophthalmic artery
Name the branches of the ophthalmic artery?
Supratroachlear
Supraorbital
Name the branches of the external carotid artery
Superior thyroid Ascending pharyngeal Lingual Facial Occipital Posterior auricular Maxillary Superficial temporal
Describe the blood supply scalp
Internal carotid
- Supra orbital
- Supra trochlear
External carotid
- Superficial temporal
- Posterior auricular
- Occipital
What are the layers of the scalp?
Skin Connective tissue - dense Aponeurosis Loose CT Periosteum
Where do the vessels of the scalp lie?
In the subcutaneous connective tissue layer
Why can injury to the scalp cause profuse bleeding?
- Walls of arteries closely attached to CT limits constriction
- Numerous anastomoses
- Opposing pull of occiptofrontalis
Why does loss of scalp not lead to bone necrosis?
Blood supply to skull is from middle meningeal
From what artery do most superficial arteries of the face arise?
External carotid
Name two branches of the maxillary artery?
Middle meningeal
Sphenopalatine
Describe the blood supply to the nasal septum
Anastomosis of arteries in Kisselbach area
Common site for nose bleed (sphenopalatine)
What are the most important branches in Kisselbachs area?
Septal branch of sphenopalatine artery from the maxillary artery
Anterior ethmoidal arteries from ophthalmic artery
Which foramina does the middle meningeal artery travel through?
Foramen spinosum
How does infection from scalp spread to the cranial cavity and affect the meninges?
Veins of scalp connect to diploid veins though emissary veins and then to dural venous sinus
Emissary veins are valveless
Do veins of the face have valves?
No
What sinuses are the facial veins connected to?
Cavernous sinus
Pterygoid sinus
What is the danger triangle of the face?
An area of face in which infections can spread through the venous system to the dural venous sinuses
How do the sigmoid sinuses exit the skull?
Continue as IJV and leave through jugular foramen
What is the IJV an indication of?
Pressure in the right atrium
What is JVP measured in?
mmH2O
How is JVP measured?
Height from sternal angle + 5cm
