Session 2 - Organisation of Blood and Lymph Systems Flashcards
Where do the right and left common carotid arteries arise from? At what level does the right common carotid artery come from?
Right common carotid – arises from bifurcation of the brachiocephalic trunk. Occurs at level of right sternoclavicular joint.
Left common carotid – comes directly off the arch of the aorta.
What branches do the common carotids give off in the neck?>
None
What spinal level does the common carotid split?
C4
What is the carotid sinus? Where is it located? What is the carotid body? Where is it located?
- Common and internal carotid are dilated, area known as carotid sinus. Involved in detecting and regulating BP
- External to carotid sinus is the carotid body – these are peripheral CRs. Detect O2 in blood and regulate breathing rate.
What is carotid sinus hypersensitivity? What must you do for these patients?
in some people, baroreceptors hypersensitive to stretch and external pressure on carotid sinus can slow HR and decrease BP, resulting in brain under perfusion and syncope. Checking pulse here not advised in these patients.
At what point of the common carotid is a common site for atheroma formation? What could an atheroma here result in?
Bifurcation of common carotid.
Could result in rupture of clot and embolus travelling to brain, lodging in smaller artery and causing a stroke.
What symptoms result from carotid artery atherosclerosis
Dizziness, headache, muscular weakness
How would you assess the severity of thickness of a common carotid atherosclerosis??
Doppler study
What is the name of the procedure where the carotid artery is cut open and the atheromatous tunica intima is removed?
carotid endarterectomy
What does the external carotid artery supply?
Head and neck external to cranium
What branches of the external carotid supply:
a) superficial face structures
b) deep face structures
a) facial and superficial
b) maxillary
What arteries supply blood to the scalp? Which are branches of external carotid and which are internal carotid?
posterior auricular, occipital, superficial temporal (external carotid)
super-orbital and supratrochlear (internal carotid arteries branches)
Why can injuries to scalp cause excessive bleeding?
- Walls of arteries bound tightly to underlying connective tissue of scalp, preventing constriction to limit blood loss.
- Numerous anastomoses formed by arteries which produce a densely vascularised area
Why do deep lacerations involving the epicranial apneurosis result in excessive bleeding?
Deep lacerations can involve the epicranial aponeurosis which is worsened by the opposing pulls of the occipital and frontalis muscles, resulting in opening of the wound.
Does the skull undergo avascular necrosis after injury? Why?
skull does not undergo avascular necrosis due to blood from alternative source, middle meningeal artery.
What is the middle meningeal artery a branch of?
Maxillary artery
What does the MMA supply?
Supplies skull and dura mater.
What is the dura mater?
Outer membranous layer covering the brain
What happens in a fracture of the pterion?
Fracture of pterion (weakest point of skull) can damage MMA, resulting in blood collecting between the dura mater and the skull, resulting in an increase in intracranial pressure.
How does the internal carotid artery enter the cranial cavity? Where is this thing located?
Carotid canal in the petrous part of the temporal bone
What does the internal carotid supply?
Brain, eyes and forehead
From where do the vertenral arteries arise from?
Subclavian arteries
Through which transverse processes does the vertebral artery travel through?
C6 - 1
How does the vertebral artery enter the cranial cavity? What happens after they enter?
- Enters cranial cavity via the foramen magnum and then converge.
- After conversion they give rise to the basilar arteries which supplies the brain
Label the branches of the thyrocervical trunk
What are the lateral, medial, and superior borders of the carotid triangle?
Superior – posterior belly of digastric
Lateral – SCM
Medial – Superior belly of omohyoid