Head and Neck Supply PDF

What happens w/ the R and L common coronary arteries? Bifurcates into internal carotid artery (supplies the brain and internal organs) and external carotid artery (supplies the face) What is the first branch of the internal carotid artery? What happens with this branch? Ophthalmic arter...

What happens w/ the R and L common coronary arteries? Bifurcates into internal carotid artery (supplies the brain and internal organs) and external carotid artery (supplies the face) What is the first branch of the internal carotid artery? What happens with this branch? Ophthalmic artery Enters into the orbit through the optic canal together with the optic nerve to supply the EOMs and structures related to the eyeball What is the nerve that runs together with the internal carotid artery and internal jugular artery? The vagus nerve (CN X) Arterial Blood Supply to the Head and Neck Major arteries that supply the head and neck: ○ Common carotid artery ○ Subclavian arteries: form parts of the branches that supplies the neck and some facial portions Direct branches of the aorta and aortic arch Differential origin from the left and right sides of the body LEFT side of the body Aorta divides in: ○ Common carotid artery ○ Left subclavian artery RIGHT side of the body Aorta divides in: ○ Brachiocephalic trunk divides in: Right common carotid artery Right subclavian artery Common carotid artery Inferior (branchless) Travels up the neck lateral to the trachea and larynx Travels in a sheath deep of the sternocleidomastoid muscle, internal jugular vein, and CN X (nerve and ganglia) At larynx level divides in: ○ Internal carotid artery (to supply the head) ○ External carotid artery (to supply the face and neck) Head and Neck Receptors: Carotid Sinus and Carotid Body Carotid sinus (Baroreceptor)  ○ Swelling that presents the common carotid artery just before it bifurcates into internal and external carotid aa (innervated by sinus branch of glossopharyngeal nerve (CN IX); some via vagus nerve) Carotid pulse (from sinus) ○ Most reliable arterial pulse ○ Palpated against the larynx at the level of the thyroid cartilage Carotid pulse (chemoreceptor) ○ Chemoreceptor for O2 levels ○ Innervated by sinus branch of glossopharyngeal nerve (CN IX); some via Vagus nerve Subclavian Arteries Supply the intracranial and extracranial structures Vertebral artery is the first branch from the subclavian artery ○ It ascends, giving off muscular branches to the deep muscles of the neck and the suboccipital muscles and ultimately enters the posterior cranial cavity to supply the brain ○ Provides 20% of the brain arterial supply ○ Remaining 80% comes from the internal carotid artery Vertebral artery gives rise the basilar R and L vertebral arteries passes through the transverse foramina from the cervical vertebrae (C6-C1) Later, both side vessels enters the skull through the foramen magnum to reach the inferior surface of the brain Close to the pons, medulla oblongata and supplies cerebellar structures Here it unites to form the basilar artery ○ Supplies the cerebellum and pons of the brain and the inner ear ○ Formed from 2 vertebral arteries ○ Located over the pons ○ Give rise to the following aa. Pontine aa. Supply base of pons and abducent nerve (CN VI) root Labyrinthine (internal auditory) aa. 15% arise from basilar, 85% aride from AICA Supply cochlea and vestibule of ear Anterior inferior cerebellar aa. (AICA) Superior cerebellar aa. Supply superior cerebellar nuclei and the cochlear cerebellar nuclei Posterior cerebellar aa. (part of the circle of Willis) A branch of the basilar artery Branches: ○ Anterior and posterior temporal branches  ○ Posterior communicating aa. ○ Medial occipital aa. Calcarine branch (comes from medial occipital aa.) that supply the visual cortex** Supplies ○ Occipital lobe Include the visual cortex ○ Lower temporal lobe Including the hippocampal formation ○ Midbrain ○ Thalamus Medial and LGN-visual nuclei, that receive synapses from the retinal ganglion cells PCA Occlusion ○ Occlusion results in a homonymous hemianopsia of the contralateral visual field w/ macular sparing ○ Preservation of macular function is thought to be related to the dual blood supply of the occipital lobe Posterior and middle cerebral aa. ○ Vertebral aa. intracranial branching Anterior spinal artery ○ Anterior portion of the spinal cord Posterior spinal artery ○ Supply the medulla and posterior spinal cord Posterior inferior cerebellar artery (PICA) ○ Supplies a small portion of the dorsal medulla and cerebellum ○ A branch of the vertebral artery ○ Supplies Dorsolateral quadrant of the medulla Include the nucleus ambiguous (CN IX, X, and XI)  Inferior surface of the cerebellum Internal Carotid Artery No branches in the neck and supply structures internal to the skull The sheath covered by the sternocleidomastoid muscle of the neck Enters the cranial cavity through the carotid foramen in the temporal bone It supplied blood to ○ Eyeball ○ Orbital structures ○ Lacrimal gland ○ Ear ○ Most of the cerebrum of the brain, pituitary gland ICA branching… ○ Ophthalmic artery Branch of the internal carotid artery OA branches ○ Central retinal artery of the retina Hyaloid artery***** derives from ^ ○ Lacrimal artery ○ Muscular branches ○ Ciliary arteries (long and short posterior a.) ○ Supraorbital artery ○ Posterior ethmoidal artery ○ Anterior ethmoidal artery ○ Recurrent meningeal branch ○ Medial palpebral arteries ○ Supratrochlear artery ○ Dorsal nasal artery ○ Posterior communicating artery Is an anastomosis b/w the internal carotid artery (ICA) w/ the posterior cerebral artery (PCA) Part of the cerebral arterial circle (Circle of Willis) Supplies: Optic chiasm*** Hypothalamus Anterior half of the ventral portion of the thalamus ○ Anterior cerebral artery (ACA) Branches: Anterior communicating artery Medial orbitofrontal artery Frontopolar artery Callsomarginal artery Pericallosal artery  Both anterior cerebral arteries are connected by the anterior communicating artery Is part of the circle of Willis (anterior part) Most common site of aneurysms in the brain**** Supply: Medial and inferior portion of the frontal lobe Medial side of the parietal lobe Corpus callosum Supplies anterior parietal and frontal lobes: Motor cortex ○ Panning, control and execution of voluntary movements Somatosensory cortex ○ Receive and analyze sensory impulses as tactile stimuli from the skin Frontal eye field (contraversive eye center; eye gaze center) ○ Visual attention and motor movements ○ Middle cerebral artery A direct branch of the ICA that lies in the middle part of the brain (close to temporal and parietal and frontal lobes) Branches: Orbitofrontal artery Precentral artery Central artery Lenticulostriate arteries Anterior and posterior parietal arteries Anterior, middle, and posterior temporal artery Supplies: The lateral surface of the frontal and parietal cortex Temporal lobe ○ Broca’s area: production of speech ○ Wernicke’s speech area: comprehension and conceptualization of speech Posterior limb and genu of internal capsule (anterior limb, posterior limb, and genu) Most of the basal ganglia ○ Caudate nucleus ○ Lentiform nucleus Putamen Globus pallidus Proximal parts of the visual radiations, as they emerge, form the lateral geniculate nucleus of the thalamus and course in Meyer’s loops (inferior retinal quadrants) Occlusion of the branches that supply Meyer’s loop fibers in the temporal lobe results in **contralateral superior quadrantanopia Arterial Circle of Willis Anastomoses of ○ The left and right internal carotid arteries along the basilar artery ○ At the base of the brain ○ Near the sella turcica (pituitary gland) Made by contributions of… ○ Internal carotid artery (ICA) ○ Anterior cerebral artery (ACA) ○ Anterior communicating artery ○ Posterior communicating artery ○ Posterior cerebral artery (PCA) Ex vivo External carotid artery Supplies: ○ Superficial areas of the neck and head ○ Small portion of ocular structures (maxillary artery branches) Infraorbital artery (inferior eyelid and lacrimal sac) Middle meningeal artery (anastomoses to the lacrimal artery) 3 main branches ○ Facial ○ Maxillary ○ Superior temporal artery Branches ○ Superior thyroid ○ Ascending pharyngeal ○ Lingual ○ Facial ○ Occipital  ○ Posterior auricular ○ Maxillary ○ Superificial temporal V2 and maxillary artery???? Inferior orbital fissure Facial artery Originate from the external carotid Courses beneath the digastric and stylohyoid muscles Cross the submandibular gland, and curves over the body mandible as the submental artery It proceeds upward and forward to the angle of the mouth Superior and inferior labial arteries go to the lips Finally becomes the angular artery supplies tissues along the side of the nose, superior and inferior eyelids Maxillary artery The larger terminal branch of the external carotid artery Begins just anterior to the ear and enters the orbit through the inferior orbital fissure as the infraorbital artery Exit the orbit through the infraorbital foramen (supplying lower eyelid, lacrimal sac) ○ When the branch exits the orbit content ^ , question Finally joins the angular and dorsonasal arteries Middle meningeal artery ○ Branch of the maxillary artery ○ Enters through the foramen spinosum ○ Supplies most of the dura mater (pia and arachnoid are supplied anterior cerebral aa.) Epidural hematoma Laceration/tear of the middle meningeal artery results in epidural (extradural) hemorrhage (outside part of the brain) Usually presents after trauma From skull fracture (0.55% of all head injury patients) Bleeding b/w skull and external dura Associated w/ adolescents and young adults (trauma) Biconvex or lenticular Favors temporal/temporoparietal region Rapidly expanding w/ arterial blood More medically successful Subdural hematoma Laceration or tear of the superior cerebral veins resulting in subdural hemorrhage Usually presents after trauma, but the worst prognosis HA, drowsiness, focal neurological deficits, and sometimes dementia Associated w/ alcoholics and elderly (trauma) Diffuse and concave Entire surface of the brain 30% if severe head injuries No lucid interval w/ underlying severe brain damage Prognosis worse than extradural Slowly expanding w/ venous blood Superficial temporal aa. Branch of the external carotid aa. Supply blood to the superficial skin (scalp), muscles, and soft tissue around the head, face and orbit Branches ○ Transverse facial artery Supplies skin of the cheek and then joins the infraorbital artery ○ Middle temporal artery Supplies temporalis muscle ○ Frontal branch and parietal branch Supplies skin and muscle of the forehead and parietal regions (scalp) Ends course by joining the supraorbital and supratrochlear arteries of the internal carotid Which arteries supply the visual cortex? Choose 2 or 3 Middle cerebral artery, posterior cerebral artery- calcarine branch VEINS: DRAINAGE SYSTEM Venous drainage of the head and neck Drains waste and deoxygenated blood towards the SVC Heart and respiratory system, reoxygenate and removes waste from the blood to returned this to the arterial circulation again (systemic circulation) Most blood draining from the head passes into 3 pairs (R and L) of veins: ○ Internal Jugular Vein (IJV) Are beneath the sternocleidomastoid muscle, lateral to the carotid arteries The paired internal jugular veins drain blood from the brain, meninges, and deep regions of the face and neck The internal jugular drains the cavernous sinus (superior and inferior ophthalmic vein) Superior ophthalmic vein receives: central retinal vein anterior ciliary veins anterior and posterior ethmoidal veins vortex veins Inferior ophthalmic vein courses back on the inferior rectus Internal jugular veins exit the cranial vault, they receive several other venous branches: Angular vein located at the junction of the veins of the forehead, orbit, and face Supraorbital, supratrochlear, superior and inferior palpebral veins the facial vein The internal jugulars join the subclavian veins on each side of the body to form the brachiocephalic veins From here blood flows into the superior vena cava ○ External Jugular Vein (EJV) Lie over the sternocleidomastoid muscle and lateral to the internal jugular veins The posterior division of the retromandibular vein becomes the external jugular vein Are more superficial and usually drains blood primarily from the posterior head and neck Descents inferiorly along the neck, terminating in the subclavian vein The anterior jugular vein drains into the external jugular vein before joins the subclavian vein ○ Vertebral veins  Within the brain, all veins branches drain into dural venous sinuses in the meninges and the cavernous sinus, the most important ○ 1) Superior sagittal sinus ○ 2) Inferior sagittal sinus ○ 3) Cavernous sinus ○ Then drains into the internal jugular vein (IJV) Maxillary vein: a short vein that drains the pterygoid plexus Pterygoid plexus: a network located b/w the pterygoid and temporalis muscles Supraorbital vein: from the scalp and forehead, this veins sends a branch through the supraorbital notch and continues to join the frontal vein forming the angular vein Supratrochlear vein: from middle scalp and forehead, this vein descends to the medial angle of the eye Cavernous Sinus Is the most clinically significant dural sinus Located on the body of the sphenoid Immediately posterior to the optic chiasm Receive venous blood from ○ the eye and facial veins (via the superior and inferior ophthalmic veins) ○ Sphenoid and middle cerebral veins and pterygoid plexus Internal Carotid Artery (ICA) enters the sinus with some cranial nerves (CNs III, IV, VI, and V1-V2) This complex web of veins contains no valves: blood can flow in any direction depending on the prevailing pressure gradients Since the cavernous sinuses receive blood from different face areas, infections of the face including the nose, tonsils, and orbits can spread easily by this route Facial vein Facial region is drained by the maxillary, facial and superficial temporal veins Origin of facial vein: ○ the angular vein Communicates with the cavernous sinus by way of the ophthalmic veins In the cheek, the facial vein receives the deep facial vein from the pterygoid plexus, and it usually ends directly or indirectly in the internal jugular vein Superficial temporal vein Lateral side of head This vein drains the forehead and scalp and receives tributaries from the veins of the temple and face In the region of the temporomandibular joint (TMJ), this vein enters the parotid gland Posterior auricular vein Begins the side of the head, in a plexus which communicates with the tributaries of the occipital, and superficial temporal veins It descends behind the auricle (ear) and joins the posterior division of the posterior facial vein to form the external jugular Occipital vein Begins in a plexus at the back of the skull Joins the deep cervical and vertebral veins Occasionally it follows the course of the occipital artery and ends in the internal jugular In other instances, it joins the posterior auricular and through it opens into the external jugular Vertebral vein Right and left vertebral veins drain deep structures in the neck such as the cervical vertebra, cervical spinal cord, and some neck muscles into the subclavian and this to the superior vena cava