The Meninges and Blood Vessels of Brain and Spinal Cord, and the Cerebrospinal Fluid 山东大学医学院 解剖教研室 李振华

Meninges of Brain and Spinal Cord The spinal cord and brain are surrounded by three membranes, the meninges. Named from the outside inward they are Dura mater 硬膜 Arachnoid mater 蛛网膜 Pia mater 软膜

The Meninges of Spinal Cord Spinal dura mater 硬脊膜 Spinal arachnoid mater脊髓蛛网膜 Spinal pia mater 软脊膜

Spinal Dura Mater 硬脊膜 Characters A dense, fibrous membrane that encloses the spinal cord and cauda equina Above, attached to circumference of foramen magnum Below, becomes thinner at level of S2, invests filum terminale to attach at back of coccyx On each side, continuous with external membrane of spinal nerves at intervertebral foramina

Spinal Dura Mater 硬脊膜 Epidural space 硬膜外隙 Subdural space 硬膜下隙 Position: lies between spinal dura mater and periosteum of vertebral canal Contents: a quantity of loose connective tissue, fat, lymphatic vessels and vertebral venous plexus, the spinal nerves on each side pass through the epidural space which is applicable for block anesthesia Subdural space 硬膜下隙

Spinal Arachnoid Mater 脊髓蛛网膜 Characters A thin, delicate, tubular membran loosely investing spinal cord Above, it is continuous with cerebral arachnoid mater

Subarachnoid Space 蛛网膜下隙 Position: lies between pia and arachnoid maters containing cerebrospinal fluid Terminal cistern 终池: the largest part of subarachnoid space extending from termination of spinal cord to level of S2, where it is occupied by nerves of cauda equina, so it is the best site for a lumbar puncture

Lumbar spinal puncture (spinal tap)

Spinal Pia Mater 软脊膜 A delicate vascular membrane that closely invests the spinal cord Denticulate ligament齿状韧带: consist of 21 pairs triangular ligaments extending from spinal cord on each side between anterior and posterior roots of spinal nerves to spinal dura mate; these ligaments help to fix position of spinal cord. Filum terminale 终丝: an extension of pia beyond conus medullaris

The Meninges of Brain Cerebral dural mater 硬脑膜 Cerebral arachnoid mater 脑蛛网膜 Cerebral pia mater 软脑膜

Cerebral Dural Mater 硬脑膜 Characters A thick and dense inelastic membrane that composed of two layers, an inner or meningeal and outer or endosteal It is in loose contact with calvaria, and most strongly adherent to base of skull

Cerebral dural mater 硬脑膜 Four septa Cerebral falx 大脑镰 Tentorium of cerebellum小脑幕－ in front there is a gap, the tentorial incisure 幕切迹, for passage of midbrain Cerebellar falx 小脑镰 Diaphragma sellae 鞍隔

Cerebral Dural Mater 硬脑膜 Sinuses of duramater 硬脑膜窦 Superior sagittal sinus 上矢状窦 Inferior sagittal sinus 下矢状窦 Straight sinus 直窦 Confluence of sinus 窦汇

Cerebral Dural Mater 硬脑膜 Transverse sinus 横窦 Sigmoid sinus 乙状窦 Superior petrosal sinuses 岩上窦 inferior petrosal sinuses 岩下窦

Cerebral Dural Mater 硬脑膜 Cavernous sinus 海绵窦 Position: lies on each side of sella turcica Traversing the cavernous sinus Internal carotid artery Abducent nerve Traversing the lateral wall of the cavernous sinus Oculomotor nerve Trochlear nerve Ophthalmic nerve Maxillary nerve

Cerebral Dural Mater 硬脑膜

The flowing of the blood in dural sinus Sup. sagittal sinus Inf. sagittal sinus Straight sinus Confluence of sinus Transverse sinus Sup. petrosal sinus Sigmoid sinus Cavernous sinus Inf. petrosal sinus Internal jugular vein

Lateral projection from a magnetic resonance venogram using time-of-flight methods. Frontal projection from a magnetic resonance venogram using time-of-flight methods.

Cerebral Arachnoid Mater 脑蛛网膜 Characters: a delicate membrane covering brain loosely, passing over sulci and entering only cerebral longitudinal and transverse fissures

Cerebral Arachnoid Mater 脑蛛网膜 Arachnoid granulations 蛛网膜粒－ project into sinuses of dura mater, serve as sites where cerebrospinal fluid diffuses into bloodstream

Subarachnoid Cisterns 蛛网膜下池 Cerebellomedullary cistern 小脑延髓池 Chiasmatic cistern 交叉池 Interpeduncular cistern 脚间池 Pontine cistern 桥池 Superior cistern 上池

Cerebellomedullary cistern

Intracranial hemorrhages… Extradural or epidural hemorrhage: blood collects between the calvaria and the periosteal layer of dura

Intracranial hemorrhages… Subdural hematoma: blood collects between the dura and arachnoid

Intracranial hemorrhages Subarachnoid hemorrhage: blood flows into the subarachnoid space and mixes with cerebrospinal fluid

Cerebral Pia Mater 软脑膜 Closely invests brain surface In some areas the pia invaginates into ventricles to take part in the formation of choroids plexus

Circulation of Cerebrospinal Fluid (CSF) Cerebrospinal fluid is a clear colorless fluid Nourishes brain Removes waste Conducts chemical signals between parts of CNS Liquid cushion for brain and spinal cord Production: produced by the choroids plexuses within the lateral, third and fourth ventricles

Choroid plexus = choroidal epithelium surrounding brain capillaries CSF volume = 150 ml 75 ml in cisterns 50 ml in subarachnoid space 25 ml in ventricles CSF formation = 450-600 ml/day

Circulation of Cerebrospinal Fluid (CSF) interventricular foramina CSF drains from lateral ventricle third ventricle mesencephalic aqueduct median and two lateral apertures fourth ventricle arachnoid granulations subarachnoid space superior sagittal sinus vein

Hydrocephalus 脑积水

Hydrocephalus 脑积水

MRI scan of head in sagittal plane. MR scan showing an enhancing mass which is a meningioma growing from the meninges at the edge of the foramen magnum. The tumour is benign but is causing compression of the brain stem and secondary hydrocephalus.

Blood Vessels of Brain and Spinal Cord

Arteries of Brain Two sources Internal carotid artery: supplies anterior 2/3 of cerebral hemisphere and parts of diencephalon Vertebral artery: supplies postterior 1/3 of cerebral hemisphere and parts of diencephalon, brain stem and cerebellum

Internal Carotid Artery 颈内动脉 Branches Anterior cerebral artery 大脑前动脉 Middle cerebral artery 大脑中动脉 Anterior choroidal artery 脉络丛前动脉 Posterior communicating artery 后交通动脉

Internal Carotid Artery 颈内动脉 Anterior cerebral artery 大脑前动脉 Joined the fellow of the opposite side by the anterior communicating artery Cortical branches: supply all medial surface of the cerebral cortex as far back as the parietooccipital sulcus and superior border of the suprolateral surface of the cerebral hemisphere Central branches: supply caudate nucleus, anterior part of lentiform nucleus and anterior limb of internal capsule

Internal Carotid Artery 颈内动脉 Middle cerebral artery 大脑中动脉 Cortical branches: supply most of superolateral surface of cerebral hemisphere and insular lobe Central branches: supply lentiform and caudate nuclei, genu and posterior limb of internal capsule (lenticulostriate artery)

Internal Carotid Artery 颈内动脉 Anterior choroidial artery 脉络丛前动脉：passes backward, enters inferior horn of lateral ventricle, and ends in choroid plexus. It supplies lateral geniculate body, posterior limb of internal capsule, middle 3/5 of crus cerebri and globus pallidus Posterior communicating artery 后交通动脉: runs backward to join posterior cerebral artery

Vertebral Artery 椎动脉 Cranial branches Branches of basilar artery Anterior and posterior spinal arteries 脊髓前、后动脉 Posterior inferior cerebellar artery 小脑下后动脉 Branches of basilar artery Anterior inferior cerebral artery小脑下前动脉 Labyrinthine artery 迷路动脉 Pontine arteries 脑桥动脉 Superior cerebellar artery 小脑上动脉 Posterior cerebral artery 大脑后动脉

Vertebral Artery 椎动脉 Posterior cerebral artery 大脑后动脉 Cortical branches: supply medial and inferior surfaces of temporal lobe and occipital lobe Central branches: supply dorsal thalamus, medial geniculate body, hypothalamus and subthalamus

Cerebral Arterial Circle ( Circle of Willis ) Formation Anterior communicating artery Both anterior cerebral arteries Internal carotid arteries Posterior communicating arteries Posterior cerebral arteries Position: lies on sella turcica around optic chiasma, tuber cinereum and mamillary bodies

Area of oxygendeprives brain Blockage Thrombus Plaque

Intracerebral hemorrhage Arteriovenous Malformation 动静脉畸形

Lenticulostriate arteries 豆纹动脉 Microaneurysm 微血管动脉瘤 Lenticulostriate arteries 豆纹动脉 Subarachnoid hemorrhage 蛛网膜下腔出血

Infarct with Punctate hemorrhage

Internal carotid arteriogram Internal carotid arteriogram. This image is a lateral projection obtained by intra-arterial digital subtraction angiography. Vertebral arteriogram. This image is a lateral projection obtained by intra-arterial digital subtraction angiography.

Veins of Brain Superficial cerebral veins Drain blood from cortex and subcortical medullary substance and empty into adjacent sinuses of dura mater Superior cerebral v. ascend over the lateral surface of the cerebral hemisphere and drain into the superior sagital sinus. Inferior cerebral v. drain into the. transverse sinus and cavernous sinus Superficial middle cerebral v. drains the lateral surface of the cerebral hemisphere . it empties into the cavenous sinus. Deep middle cerebral v. drains insula and is joined by the anterior cerebral and striate veins to form the basal vein.

Veins of Brain Deep cerebral veins Drain deeper parts of hemispheres, basal nuclei, internal capsule diencephalon and choroid plexus Ultimately form great cerebral vein 大脑大静脉 which enter straight sinus

Arteries of Spinal Cord Two sources Anterior and posterior spinal arteries Branches of segmental arteries: radicular arteries of posterior intercostals arteries, lumbar arteries, and lateral sacral arteries Damage area: T1~T4,ventral part of L1 vascular ring ( vasocorona )

Arteries of Spinal Cord Posterior spinal a. Vascular ring Anterior spinal a. Radicular a.

Veins of Spinal Cord Spinal veins: draininto internal vertebral venous plexus