Arteries of the head and neck Flashcards
Where does the right common carotid artery arise?
from the bifurcation of the brachiocephalic trunk at the level of the right sternoclavicular joint
Where does the left common carotid artery arise
directly from the arch of the aorta
Where do the carotid arteries split into the internal and external carotid arteries?
Level of the thyroid cartilage T4
What is the carotid sinus?
common and internal carotid are slightly dilated so important for detecting and regulating blood pressure
What does the carotid sinus contain?
baroreceptors which detect stretch to measure blood pressure, this information is fed to the brain and is used to regulate blood pressure
What happens if someone has hypersensitivity in there carotid sinus baroreceptors?
In some people the baroreceptors are hypersensitive to stretch so if is external pressure is applied will cause slowing of heart rate, decrease in blood pressure and brain becomes underprofused so syncope occurs- checking pulse here is not advised for these patients
Where is the carotid body and what is it?
Carotid body- external to the carotid sinus- nervous cells that act as peripheral chemoreceptors so detect O2 content of blood which is passed on to the brain to regulate breathing rate
How does the internal carotid artery enter the cranial cavity?
Carotid cana;
What does the internal carotid artery supply?
Brain Eyes Forehead
Which artery in the head and neck is atherosclerosis most likely to occur?
Internal carotid artery
What will a reduction in blood flow to the brain cause?
Headaches, dizziness, muscular weakness, stroke
What will atheroma forming cause?
This will cause thickening of the tunica intima and will reduce the blood flow to the brain
What is the doppler study?
Assess severity of athersclerotic plaque
What is a carotid endarterectomy?
Artery can be opened and atheromatous tunica intima can be removed
Where do vertebral arteries arise?
subclavian arteries
Where do vertebral arteries ascend through?
Ascend up the posterior side of the neck through foramen transversarium Enter cranial cavity via the foramen magnum
What do vertebral arteries become?
Basilar arteries
What do basilar arteries supply?
Brain
What do external carotid arteries supply?
areas external to the cranium
Where does the external carotid artery travel?
Travels up the neck, posterior to the mandibular neck and anterior to the lobule of the ear ending at the parotid gland
What does the external carotid artery divide into?
The maxillary and superficial temporal artery
What 6 branches does the external carotid artery branch into?
Superior thyroid artery Lingual artery Facial artery (superficial areas of the face) Ascending pharyngeal artery Occipital artery Posterior auricular artery
What is the blood supply to the scalp?
Posterior auricular, occipital and superficial temporal arteries
What are the three reasons excessive bleeding occurs in the scalp?
Walls of the arteries are tightly and closely bound to connective tissue which prevents constiction Numberous anastomoses means very vascularised- dense blood supply Deep lacerations can involve epicranial aponeurosis which is worsened by the opposing pulls of the occipital and frontalis muscles
What is the middle meningeal artery a branch of?
Maxillary artery
What does the middle meningeal artery supply?
Skull and dura
What happens if a skull fracture occurs at the pterion?
can injure or lacerate the MMA, this means blood may collect between the skull and the dura causing an extradural haematoma
What happens in an extradural haematoma?
This causes an increase in intracranial pressure which causes; nausea, vomiting, seizures, bradycardia and limb weakness
What is the treatment for an extradural haemotoma?
Diuretics
Burr holes if serious
Label the brachiocephalic trunk, vertebral artery, right subclavian artery and basilar artery?
Label the arch of the aorta, subclavian arteries, common carotid artery and brachiocephalic trunk?
Label the right internal carotid, right subclavan, right external carotid, right common carotid and brachiocephalic trunk?
Label this picture
