S2 blood vessels Flashcards
superior border of carotid triangle?
importance of the triangle?
posterior belly of digastric muscle
access site for carotid artery which is an important central pulse
medial/inferior border of carotid triangle?
superior belly od omohyoid muscle
lateral border of carotid triangle?
medial border of sternocleidomastoid
what level does bifurcation of common carotid occur?
C4
within carotid triangle
what is carotid endarterectomy?
Removal of plaque tissue in the carotid artery
> common site is the bifurcation
make incision in neck and carotid
what is carotid sinus massage? when is it performed?
performed if patient is tachycardic>trigger baroreceptors
massage/ put pressure on the site of the carotid bodies (within carotid sinus)
importance of internal jugular vein?
- large central vein
- superficial (easy to access)
- good site for central venous line > IV/ theatre
canulation
route of internal carotid arteries
give off no branches in neck
enter base of skull via carotid canal
supplies intracranial structures
vertebral arteries arise from? route?
L and R subclavian
ascend up cervical vertebrae (C6-C1) through transverse foramina
enter base of skull via foramen magnum
supply brain with blood
internal carotid artery route
passes through carotid canal (temporal bone) through the base and enter skull
enters cranium and makes an S shaped bend
moves through cavernous sinus
where is cavernous sinus found
which structures run through?
upper surface of sphenoid bone
- carotid artery
- CN 3 oculomotor
- CN 4 trochlear
- CN 6 abducens
- 2 branches of CN 5 (trigeminal > ophthalmic and maxillary branches)
O TOM CAT
branch of internal carotid artery that supplies the scalp?
ophthalmic artery
its branches > supratrocheal artery AND supra-orbital artery
branch of internal carotid that supplies optic nerve/ retina
ophthalmic artery
branch>central retinal artery
embolus can lodge here and cause sight loss
main branches of internal carotid artery
ophthalmic artery
anterior cerebral artery
middle cerebral artery
posterior communicating artery
distribution of external carotid
superior thyroid ascending pharyngeal lingual facial occipital posterior auricular maxillary superficial temporal
(remember Some Anatomists Like Freaking Out Poor Medical Students)
clinical importance of superficial temporal artery
clinical condition:
giant cell arteritis OR temporal arteritis
- frequent headaches
- scalp tenderness over temple (hurt when brushing hair)
- jaw pain when eating
- loss/ vision change
> can lose eyesight if not treated
what supplies blood to scalp
internal carotid
>supra-orbital and supratrocheal art
external carotid
> superficial temporal
> posterior auricular
> occipital art
layers of scalp
Skin Connective tissue Aponeurosis Loose areolar tissue Periosteum
(remember S.C.A.L.P)
why does scalp bleed a lot?
- artery walls held open by connective tissue so can’t constrict>no elastic recoil
- lots of anastomoses
- deep laceration to occipito frontal muscle can pull cuts open
what does maxillary artery supply and its key branches?
maxillary artery is a branch of external carotid. supplies deeper facial structures
its branches:
middle meningeal > supply dura mater (enters via foramen spinosum)
sphenopalatine art> supplies nasal septum (important in nose bleeds)
what happens with middle meningeal artery rupture?
occur from blow to side of head
fracture occur in pterion> rupture artery
blood leak into area below
ripping dura mater away from bone wall
> extradural hematoma
- requires craniotomy (open cranium relieve pressure)
drainage of scalp?
into dural venous sinus through emissary veins
facial vein drains to?
clinical importance?
cavernous sinus
> infection can spread via facial vein and end up in the dural venous sinuses (deep veins)
how to test jugular venous pressure?
using R internal jugular vein - patient at 45 degrees - head tilt to left - look for pulsations through SCM muscle > measure hight from sternal angle and add 5cm to give estimate of right atrial pressure in cmH20
