Blood Supply Head & Neck 2 (HB, 11.pdf PDF

Leena's Notes 100924 HEAD and NECK BLOOD SUPPLY (PART 2) Dr. Giam Vega-Meléndez Systemic Biomedical Sciences III October 2024  MIDDLE CEREBRAL ARTERY > most extensive branch from ICA A direct branch of the ICA that lies in t...

Leena's Notes 100924 HEAD and NECK BLOOD SUPPLY (PART 2) Dr. Giam Vega-Meléndez Systemic Biomedical Sciences III October 2024  MIDDLE CEREBRAL ARTERY > most extensive branch from ICA 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 motor function. Central artery ↑ Rolandic Ant. Post artery - – parts of brain – Lenticulostriate arteries – Anterior and posterior parietal arteries – Anterior, middle and posterior temporal artery  MIDDLE CEREBRAL ARTERY I also supplies nuclei for : Supplies: audition 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 (V1) Gaze Centre (Visual · Eye assoc Lateral Brain > more supply  MIDDLE CEREBRAL ARTERY (MCA) Supplies suppliedbya – 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  MIDDLE CEREBRAL ARTERY (MCA) OCCLUSION Supply… ( final target = v – 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) more related to Temporal side > Superior Visual Fields Occlusion of the branches that supply Meyer’s loop fibers in the temporal lobe results in ***contralateral superior quadrantanopia  BASILAR ARTERY Cerebellum Formed from two vertebral arteries Located over the pons Give rise to the following arteries – Pontine aa. supply base of pons and abducent nerve (CN VI) root 7) Abducen's nerve – Labyrinthine (internal auditory) aa. 15% arise from basilar, 85% arise from AICA Supply cochlea and vestibule of ear – Anterior inferior cerebellar aa. (AICA) – Superior cerebellar aa. Supply superior cerebellar nuclei and the 15% cochlear cerebellar nuclei 85 % AICA : from Basilar – Posterior cerebral aa. & end of Basilar Artery artery (part of the Circle of Willis) PICA : from Vertebral artery  POSTERIOR CEREBRAL ARTERY (PCA) I located in VI Is a branch of basilar artery Which arteries supply VI? 1) Middle Cerebral actory Branches: Calcarine 2) branch 3) PCA – Anterior and posterior temporal branches – Posterior communicating aa. – Medial occipital aa. Calcarine branch (comes from medial occipital aa.) that supply the VISUAL CORTEX  POSTERIOR CEREBRAL ARTERY (PCA) 2 > lesion 1 here will Occipital impact vision bc Supplies V1 Lower Temporal Lobe Supplies: – Occipital lobe Include the visual cortex (VD – Lower temporal lobe Including the hippocampal formation  POSTERIOR CEREBRAL ARTERY (PCA) Thalamus Supplies – Midbrain – Thalamus. also have auditory info · Medial and lateral geniculate nuclei LGN- VISUAL NUCLEI, that receive synapses from the retinal ganglion cells ~ make up Pullinar : Nuclei · If Rupture related to LGN; which artery affected ? 1 Ans : Posterior Cerebral Artery (PCA) POSTERIOR CEREBRAL ARTERY (PCA) OCCLUSION Occlusion results in a homonymous hemianopsia of the contralateral visual field with macular sparing Preservation of macular function is thought to be related to the dual blood supply of the occipital lobe – posterior & middle cerebral aa.  POSTERIOR COMMUNICATING ARTERY Is an anastomosis between the internal carotid artery (ICA) with the posterior cerebral artery (PCA) Part of the cerebral arterial circle (Circle of Willis)  POSTERIOR COMMUNICATING ARTERY > Vertical damage Damage of PCA = 1 canaffect vision Hemianopsia Supplies: in both Optic eyes Chiasm b/c > Horizontal damage = – Optic chiasm Quadrantanopia – Hypothalamus – Anterior half of the ventral portion of the thalamus  ARTERIAL CIRCLE OF WILLIS 1) will affect Visual Info. 1 Damage · : Anastomoses of 2) affectEndocrine info. – the left and right internal carotid arteries along the with basilar artery – at the base of the brain – near the sella turcica (pituitary gland) middle of circle of will is > Hypophysis = in  ARTERIAL CIRCLE OF WILLIS Ad At Made by contributions of… Internal Carotid Artery (ICA) Anterior Cerebral Artery (ACA) Anterior Communicating Artery Posterior Communicating Artery Posterior Cerebral Artery (PCA) HUMAN ARTERIAL CIRCLE OF WILLIS ex vivo. Optic Chiasm 7 > Hypophysis , Mammalary Bodies in Brainstem HUMAN ARTERIAL CIRCLE OF WILLIS in vivo Optic Nerves Optic Chiasm Optic Tract Hypophysis CT > Cavernous Sinus  EXTERNAL CAROTID ARTERY v2 Maxillary Antery · , go through Interior Orbital Fissure External carotid artery supplies – superficial areas of the neck and head – small portion to ocular structures (maxillary artery branches) Infraorbital artery (inferior eyelid and lacrimal sac) Middle meningeal artery (anastomoses to the lacrimal artery) Three main branches: – Facial – Maxillary – Superficial temporal artery  BRANCHES OF EXTERNAL CAROTID ARTERY Superior Thyroid target > = thyroid Ascending Pharyngeal < pharynx Lingual Facial 39 nutrients ives O2 to all muscles for Occipital facial expression Posterior Auricular External supplies < : ear Maxillary M1 internal eye + Superficial Temporal to temporal bones  FACIAL ARTERY Originate from the external carotid Courses beneath the digastric and stylohyoid muscles (floor of mouth) Crosses the submandibular gland, and curves over the body of the 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 supplies Orbiculus Oris (mouth) > Finally becomes the angular artery supplies tissues along the side of the nose, superior and inferior eyelids > via Arcade arteries  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 thru the infraorbital foramen (supplying lower eyelid, lacrimal sac) Finally joins the angular and dorsonasal arteries* 7 Infraoritate BRANCHES OF MAXILLARY ARTERY  MAXILLARY ARTERY- MIDDLE MENINGEAL AA. Branch of the maxillary artery Enters through the foramen spinosum Supplies most of the Dura mater supplies Anterior Cerebral artery · : , - Arachnoid Pia Matter  Epidural Hematoma s rupture outside Dura Matter Cat Skull o Dura) Laceration of the medial meningeal artery 7 aka > Hemorrhage results in epidural (extradural) hemorrhage Usually presents after trauma From skull fracture (0.55·patients) Bleeding between the skull and external dura Associated with adolescents and young adults (trauma) Better prognosis ·  Subdural Hematoma Laceration of the superior cerebral veins results in subdural hemorrhage Usually presents after trauma, but worst prognosis death Headache, drowsiness, focal neurological deficits, sometimes dementia Associated with alcoholics and elderly (trauma) 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 cheek and then joins the infraorbital artery – Middle temporal artery Supplies temporalis muscle & – Frontal branch and parietal branch: Supplies skin and muscles of the forehead and parietal regions (scalp) Ends course by joining the supraorbital and supratrochlear arteries of the internal carotid  VEINS: V DRAINAGE SYSTEM > arteries supplying a tissue = "Frrigation"  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 B returned this to the arterial c) vein circulation again (systemic circulation) · a), b) c) < most important a) , draining structures  VENOUS DRAINAGE Most blood draining from the head passes into three pairs (right and left) of veins: – Internal Jugular Vein (IJV) – External Jugular Vein (EJV) – Vertebral Veins  BRAIN VENOUS DRAINAGE Within the brain, all veins 2 3 branches drain into dural venous sinuses in the > Hypophysis : meninges and the pituitary gland · cavernous sinus, the most important. Then drains into the internal jugular vein (IJV) ~ Vein Superior Vena join Lo Brachiocephalic > , Pulm Trunk Cava< Right Atrium.  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  INTERNAL AND EXTERNAL JUGULAR VEINS The internal jugular veins - are beneath the sternocleidomastoid muscle, lateral to the carotid arteries External jugular veins – lie over the sternocleidomastoid muscle and lateral to the internal jugular veins  INTERNAL JUGULAR VEIN 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 VEIN Internal jugular veins exit the cranial vault, they receive several other venous branches: – Angular vein located at junction of the veins of the forehead, orbit, and face – Supraorbital, suprathroclear, 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 superior vena cava  EXTERNAL JUGULAR VEIN 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  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  VENOUS DRAINAGE Maxillary vein – a short vein that drains the pterygoid plexus Pterygoid Plexus – a network located between the pterygoid and temporalis muscles Supraorbital vein – from the scalp and forehead, this vein 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  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