Vascular Supply of the Head and Neck

genana2 - finals

Carotid Arteries

• Supply majority of the head and neck region along with the vertebral arteries

• Primary vessels supplying blood to the brain and face

Right Common Carotid

Originates in the neck from the brachiocephalic artery

Left Common Carotid Artery

Arises in the thorax from the arch of the aorta

Carotid Arteries

• Trajectory is upward, to the brain, neck, and face

• Originate posterior to the sternoclavicular joints in the neck

• Contained within the carotid sheath posterior to the sternocleidomastoid

Artery

• Carries oxygenated blood

• From the heart to organs

• blood moves upward coz its from the heart

Vein

• Carries deoxygenated blood

• From the organs to heart

• blood moves downward coz it will go sa heart

Carotid Bifurcation

• Point where each common carotid artery splits into internal carotid artery and external carotid artery

• At the level of:

  • Fourth cervical vertebra (C4)

  • Laryngeal prominence

Carotid Bifurcation

Landmark for the carotid body and carotid sinus

Carotid body

chemoreceptor sensitive to decreased blood oxygen, increased carbon dioxide, and decreased blood pH

Carotid sinus

baroreceptor that respond to stretch of blood vessel and maintains blood pressure

Carotid Bifurcation

• Point where each common carotid artery splits into two:

• Internal carotid artery - supplies the brain

• External carotid artery - supplies the neck and face

Internal carotid artery

supplies the brain

External carotid artery

supplies the neck and face

Carotid Bifurcation

Common site for atherosclerotic plaque buildup

External Carotid Artery

• Major blood vessel from the common carotid artery that supplies the head and neck, including the face, scalp, and upper neck

• Ascends upwards and laterally, and gives off eight branches

External Carotid Artery

Has eight branches:

• Superior thyroid artery

• Ascending pharyngeal artery

• Lingual artery

• Facial artery

• Occipital artery

• Posterior auricular artery

• Maxillary artery

• Superficial temporal artery

External Carotid Artery

• Eventually enters the parotid gland to give off its terminal branches:

  • Superficial temporal artery

  • Maxillary artery

• Its branches anastomose with the branches from the contralateral external carotid artery, allowing for collateral circulation

Superior Thyroid Artery

• External Carotid Artery

• Stems from the external carotid artery at the level of the hyoid bone

• Supplies the thyroid, muscles of the larynx, some muscles of the neck

Ascending Pharyngeal Artery

• External Carotid Artery

• Stems from the external carotid artery near the carotid bifurcation

• Supplies the pharynx, eustachian tube, tympanic membrane

Lingual Artery

• External Carotid Artery

• Stems from the external carotid artery at the level of C3 vertebrae

• Supplies the tongue, salivary glands, soft palate, and muscles attached to the hyoid bone

Facial Artery

• External Carotid Artery

• Stems from the external carotid artery beneath the ramus of the mandible

• Supplies the muscles of the face, cervical lymph nodes, lips, and parts of the nose

Occipital Artery

• External Carotid Artery

• Stems from the external carotid artery at the level of the

  posterior belly of the digastric muscle

• Supplies the dura mater, auricle, sternocleidomastoid, occipitofrontalis

Posterior Auricular

• External Carotid Artery

• Stems from the external carotid artery above the stylohyoid muscle

• Supplies the semicircular canals, bony tympanic cavity, tympanic membrane, external auditory meatus

Internal Carotid Artery

• Major blood vessel that supplies the brain with oxygenated blood

• After bifurcation, it continues through the carotid sheath to enter the carotid canal of the temporal bone

• Does not have branches in the neck

Bouthillier Classification

• Internal Carotid Artery

• Classification of the internal carotid artery based on angiographic appearance

• Describes the segments anatomically and the compartments through which they travel

cervical segment

• Bouthillier Classification

• C1

petrous segment

• Bouthillier Classification

• C2

lacerum segment

• Bouthillier Classification

• C3

cavernous segment

• Bouthillier Classification

• C4

clinoid segment

• Bouthillier Classification

• C5

ophthalmic segment

• Bouthillier Classification

• C6

communicating (terminal) segment

• Bouthillier Classification

• C7

Circle of Willis

At the cranial cavity, this anastomoses to form a part of the _______________

Vertebrobasilar System

Arterial system that provides circulation to the cervical spinal cord, cerebellum, brainstem, and posterior cerebrum

Vertebrobasilar System

Comprised of

• Vertebral arteries (2)

• Basilar artery (1)

Vertebral Artery

• Divides into four segments along its course:

  • V1 (Pre-foraminal segment)

  • V2 (Foraminal segment)

  • V3 (Atlantic segment)

  • V4 (Intracranial segment)

Pre-foraminal segment

• Vertebral Artery

• V1

Foraminal segment

• Vertebral Artery

• V2

Atlantic segment

• Vertebral Artery

• V3

Intracranial segment

• Vertebral Artery

• V4

V1 (Pre-foraminal segment)

• Vertebral Artery

• Arises from the first part of the subclavian artery

• Angles posteriorly behind the common carotid artery to enter the transverse foramen of C6

V2 (Foraminal segment)

• Vertebral Artery

• Ascends through the transverse foramina of the cervical vertebrae of C6 to C3

V3 (Atlantic segment)

• Vertebral Artery

• Most tortuous part

• Begins at the transverse foramen of C2, enters transverse foramen of C1, then it curves posteriorly around the lateral mass of C1 to enter the spinal canal

V4 (Intracranial segment)

• Vertebral Artery

• Segment that enters the intracranial space through the

  foramen magnum

• Eventually gives formation to the basilar artery

Basilar Artery

Provides arterial supply to the brainstem and posterior cerebral hemispheres

Basilar Artery

• Courses anterosuperiorly to the pons, giving off:

  • Anterior inferior cerebellar arteries

  • Pontine arteries

  • Superior cerebellar arteries

• As it approaches the pituitary gland, it gives branches to the:

  • Posterior cerebral arteries

  • Posterior communicating arteries

Anterior Circulation and Posterior Circulation

The blood supply of the brain is divided into:

Anterior Circulation

• From the internal carotid arteries

• Supplies majority (anterior and deep parts) of the cerebrum

Posterior Circulation

• From the vertebrobasilar system

• Supplies cervical spinal cord, cerebellum, brainstem, posterior cerebrum

Circle of Willis

• An anatomical structure that provides an anastomotic connection between the anterior and posterior circulations

• Provides collateral flow to affected brain regions in the event of arterial incompetency

• Prevents ischemia in the event of a single vessel occlusion

Circle of Willis

• Located in the subarachnoid space

• In close proximity to the optic chiasm

• Pentagonal in shape

• Formed by 5 vessels

Anterior communicating artery

• Circle of Willis

• A short vessel that connects the two anterior cerebral arteries

Anterior cerebral arteries

• Circle of Willis

• Branches of the internal carotid artery

Internal carotid arteries

• Circle of Willis

• Continues after contributing to the Circle of Willis as the middle cerebral artery

Posterior communicating arteries

• Circle of Willis

• Connects the internal carotid and posterior cerebral arteries

Posterior cerebral arteries

• Circle of Willis

• Terminal branches of the basilar artery

Stroke

• An emergency medical condition characterized by an acute compromise of the cerebral perfusion or vasculature

• When a part of brain loses its blood supply

hemorrhagic stroke

hemorrhage/blood leaks into brain tissue

ischemic stroke

clots stops blood supply to an area of the brain

Penumbra

salvageable part of the brain

Ischemic core

brain tissue destined to die

Neurons

• __________ are cells that are unable to regenerate after damage

• Permanent brain damage

Stroke

_________ is the leading cause of adult disability worldwide

BE FAST

• balance - loss of balance, head ache or dizziness

• eyes - blurred vision

• face - one side of the face is drooping

• arms - arm or leg weakness

• speech - speech difficulty

• time - time to call for ambulance immediately