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Extracranial Cerebrovascular Evaluation. Anatomy. Carotid Artery Anatomy. Branches of the Aortic Arch Innominate Left CCA Left Subclavian Innominate branches into Right CCA Right Subclavian. Rt. Common Carotid A. Rt. Subclavian A. Lt. Common Carotid A. Lt. Subclavian A. Innominate A.
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Carotid Artery Anatomy • Branches of the Aortic Arch • Innominate • Left CCA • Left Subclavian • Innominate branches into • Right CCA • Right Subclavian
Rt. Common Carotid A Rt. Subclavian A Lt. Common Carotid A Lt. Subclavian A Innominate A
Carotid Artery Anatomy • Subclavian divided into three parts by Scaleneus Anterior muscle. • First part lies medial to the muscle. • Second part lies posterior to the muscle. • Third part lies lateral to the muscle
Carotid Artery Anatomy • Branches of the first part of the Subclavian Artery • Vertebral Artery • Internal Mammary • Thyrocervical Trunk • Thyrocervical Trunk • Suprascapular • Inferior Thyroid • Transverse Cervical
Carotid Artery Anatomy Right CCA • Begins at the bifurcation of the Innominate artery behind the right sternocostal joint. • Has only a cervical portion.
Carotid Artery Anatomy Left CCA • Springs from the highest part of the arch of the aorta to the left of and in a plane posterior to the Innominate artery. • Has a thoracic and cervical portion.
Carotid Artery Anatomy Left CCA • The thoracic portion begins at the arch of the aorta and ascends in the superior mediastinum to the level of the left sternocostal joint where it becomes continuous with the cervical portion
Carotid Artery Anatomy Cervical Portion of Both CCA • Ascends obliquely upwards from the SCJ • Ends at the level of the upper border of the thyroid cartiage where it divides into: • Internal Carotid Artery (ICA) • External Carotid Artery (ECA)
Carotid Artery Anatomy ICA • Begins at the level of the upper border of the thyroid cartiage. • Consist of four portions. • Cervical • Petrous • Cavernous • Cerebral
Carotid Artery Anatomy Cervical portion • Runs perpendicularly upward in front of the transverse processes of the upper three cervical vertebrae. • Ends at the carotid canal in the petrous portion of the temporal bone.
Carotid Artery Anatomy Petrous portion • Enters the carotid canal in the petrous portion of the temporal bone. • Ascends a short distance. • Curves forward and medialward. • Ascends again as it leaves the skull.
Carotid Artery Anatomy Cavernous Portion • Artery is situated between the layers of the dura mater forming the cavernous sinus. • It is covered by the lining membrane of the sinus. • Ascends towards the posterior clinoid process. • Then passes forward by the side of the body of the sphenoid bone.
Carotid Artery Anatomy Cavernous Portion • Curves upward on the medial side of the anterior clinoid process. • Perforates the dura mater forming the roof of the sinus.
Carotid Artery Anatomy Cerebral Portion • After piercing the dura mater on the medial side of the clinoid process • Passes between the optic and occulomotor nerves to the anterior perforated substance at the medial extremity of the lateral cerebral fissure. • Gives off its terminal branches
Carotid Artery Anatomy Ophthalmic Artery • Divided into two groups • Orbital group – distributed to the orbit and surrounding parts • Occular group – distributed to the muscles and bulb of the eye.
Carotid Artery Anatomy Orbital group • Lacrimal • Supraorbital • Posterior Ethmoidal • Anterior Ethmoidal • Medial Palpebral • Frontal • Dorsal Nasal
Carotid Artery Anatomy Occular group • Central artery of the Retina • Short Posterior Ciliary • Long Posterior Ciliary • Anterior Ciliary • Muscular
Carotid Artery Anatomy Terminal Branches of the ICA • Anterior Cerebral • Middle Cerebral • Posterior Communicating
Carotid Artery Anatomy Anterior Cerebral (ACA) • Arises from the ICA at the medial extremity of the lateral cerebra fissure • Passes forward and medialward across the anterior perforated substance • Passes above the optic nerve to the commencement of the longitudinal fissure
Carotid Artery Anatomy Anterior Cerebral • Here it comes into close relationship with the opposite artery • Connected ti the opposite artery by a short trunk, the anterior communicating artery (ACoA)
Carotid Artery Anatomy Middle Cerebral (MCA) • Largest branch of the ICA • Runs first lateralward in the lateral cerebral fissure • The it runs backward and upward on the surface of the insula
Carotid Artery Anatomy Posterior Communicating Artery • Runs backward form the ICA • Anastomoses with the Posterior Cerebral Artery (PCA) a branch of the Basilar Artery.
Carotid Artery Anatomy Anterior Choroidal • Arises from the ICA, near the PCoA • Passes backward and lateralward between the temporal lobe and the cerebral peduncle • Enters the inferior horn of the lateral ventricle through the choroidal fissure ends in the choroid plexus
Carotid Artery Anatomy ECA • Begins at the level of the upper border of the thyroid cartiage. • Runs posterosuperiorly to the region between the neck of the mandible and the lobule of the auricle • Terminates by dividing into two terminal branches, the Internal Maxillary and Superficial Temporal arteries.
Carotid Artery Anatomy Branches of the ECA • Anterior Branches • Superior Thyroid • Lingual • Facial (External Maxillary) • Ascending Branch • Ascending Pharyngeal
Carotid Artery Anatomy Branches of the ECA • Posterior Branches • Occipital • Posterior Auricular • Terminal Branches • Superficial Temporal • Internal Maxillary
Vertebral Artery Anatomy Vertebral Artery • First branch of the Subclavian • Arises from the upper and back of the first part of the Subclavian Artery • Ascends in foramina in the transverse processes of the upper six cervical vertebrae
Vertebral Artery Anatomy Vertebral Artery • Winds behind the superior articulating surface of the atlas • Enters the skull through the foramen magnum • Unites at the lower border of the pons with the artery of the opposite side to form the Basilar artery
Vertebral Artery Anatomy Vertebral Artery • Divided into 4 segments • V1 - Segment from the origin of the verterbral artery to its entrance into the foramen of the transverse process • V2 – Segment of the vertebral artery that courses cranially through the foramina of the transverse processes
Vertebral Artery Anatomy Vertebral Artery • V3 – Segment that extends from the artery’s exit at the axis to its entrance into the spinal canal • V4 – Segment from point of perforation of the dura to the origin of the basilar artery
Vertebral Artery Anatomy Basilar Artery • Formed by the junction of the two vertebral arteries. • Extends from lower to upper border of the pons, lying in its median groove. • Ends by dividing into the two Posterior Cerebral arteries.
Vertebral Artery Anatomy Basilar Artery Branches • Pontine • Internal Auditory • Anterior Inferior Cerebellar • Superior Cerebellar • Posterior Cerebral
Carotid Artery Anatomy Circle of Willis • Anterior Circulation • ICA • MCA • ACA • ACoA • PCoA • Posterior Circulation • Vertebral Artery • Basilar • PCA