颈内动脉平甲状软骨上缘水平起自颈总动脉,按其形成,以颅底的颈动脉管外口为界,分为颅外段和颅内段。颅外段又称为颈段,自颈总动脉分叉处至颅底,为颈内动脉各段中最长的一段。颈内动脉先在颈外动脉的后外侧上行,后转至颈外动脉的后内侧沿咽侧壁达颅底。颅内段始于颈内动脉岩尖出颈内动脉管处,在此颈内动脉位于三叉神经半月节的内侧,与其仅隔一层硬膜袖套,颈内动脉破裂孔上方,向上、向前、内侧走形,达到蝶鞍后部的下外侧。此段的颈内动脉全程大部行于骨性管道内,在入海绵窦处较为狭窄,并与咽鼓管和鼓室紧邻。颈内动脉在后床突附近入海绵窦,稍上升后转为近水平位沿蝶骨体两侧的颈动脉沟呈“S”形前行,达前床突后沿前床突内侧的凹沟弯转向上,在前床突的内侧出海绵窦,在海绵窦内的颈内动脉有一些分支(表5-2,图5-1,图5-3至图5-12)。脑膜垂体干是一支恒定的血管,起自海绵窦内颈内动脉前行段开始部分的背侧(图5-4),其分支包括小脑幕动脉,供应小脑幕及小脑幕的岩骨附近;脑膜背侧动脉,供应鞍背及斜坡的硬脑膜;垂体下动脉,供应垂体的后部。第二支是海绵窦下外侧干,它规律地发自颈内动脉海绵窦段的较远端,供应海绵窦内的神经组织、海绵窦壁、三叉神经节、中颅窝底海绵窦周围的硬脑膜及小脑幕游离缘。最后一支是包膜动脉,它分为前、后两支,供应鞍底硬脑膜和垂体,此动脉常有缺失。颈内动脉在前床突的下内侧出海绵窦,穿过硬脑膜进入颈内动脉池。颈内动脉床突上段全程在颈内动脉池内走行,向上、向后,略向外侧至颈内动脉分叉部(图5-3)。海绵窦段上段颈内动脉的分支包括:眼动脉,发自颈内动脉的前内侧和上内侧,供应眼球及眼副器(图5-4);垂体上动脉,发自颈内动脉的下内侧,供应垂体柄、垂体前叶和视交叉(图5-4);后交通动脉,发自颈内动脉的下外侧(图5-3);脉络膜前动脉,发自远端颈内动脉的下外侧,走向钩回;最后颈内动脉分成大脑前动脉和大脑中动脉(图5-3)。
表5-2 颈内动脉的分支及分布
续表
1.颈内动脉 internal carotid artery;2.大脑前动脉 anterior cerebral artery;3.大脑中动脉 middle cerebral artery;4.后交通动脉posterior communicating artery;5.脉络膜前动脉 anterior choroidal artery;6.大脑后动脉 posterior cerebral artery
图5-3 颈内动脉床突上段及其主要分支
1.破裂孔 foramen lacerum;2.颈内动脉海绵窦段前曲 cavernous segment forward of ICA;3.颈内动脉海绵窦段后曲 cavernous segment backward of internal carotid artery;4.眼动脉 ophthalmic artery;5.垂体上动脉 superior hypophyseal artery;6.脑膜垂体干 meningohypophyseal trunk;7.垂体柄 pituitary stalk;8.后床突 posterior clinoid process
图5-4 颈内动脉海绵窦段及其分支
1.颈内动脉 internal carotid artery;2.大脑前动脉 A1段 anterior cerebral artery A1 segment;3.大脑前动脉 A2段anterior cerebral artery A2 segment;4.前交通动脉 anterior communicating atery;5.回返动脉 recurrent artery of heubner;6.额极动脉 frontopolar artery;7.中央短动脉 short central artery;8.胼胝体正中动脉 median callosal artery;9.胼周动脉 pericallosal artery;10.胼缘动脉 callosomarginal artery;11.额叶 frontal lobe;12.视神经 optic nerve;13.垂体柄 pituitary stalk;14.终板terminal lamina
图5-5 大脑前动脉及前交通复合体
1.大脑前动脉 A1段 anterior cerebral artery A1 segment;2.前交通动脉 anterior communicating artery;3.大脑前动脉 A2段anterior cerebral artery A2 segment;4.回返动脉 recurrent artery of heubner;5.内侧眶额动脉 internal orbitofrontal artery;6.额极动脉 frontopolar artery;7.胼周动脉 pericallosal artery;8.胼缘动脉(大脑前动脉 A3段)callosomarginal artery(anterior cerebral artery A3 segment);9.额前内侧动脉 anterior internal frontal artery;10.颈内动脉 internal carotid artery
图5-6 大脑前动脉主干及其分支
1.内侧眶额动脉 internal orbitofrontal artery;2.额极动脉 frontopolar artery;3.胼周动脉 pericallosal artery;4.胼缘动脉callosomarginal artery;5.额前内侧动脉 anterior internal frontal artery;6.额中间内侧动脉 middle internal frontal artery;7.额后内侧动脉 posterior internal frontal artery;8.旁中央动脉 paracentral artery;9.楔前动脉 precuneal artery;
A1~A5.大脑前动脉A1~A5段anterior cerebral artery A1~A5 segment
图5-7 大脑前动脉皮层支走行
1.豆纹动脉 lenticulostriate artery;2.外侧眶额动脉 external orbitofrotal artery;3.上干 superior trunk;4.中干 middle trunk;5.下干 inferior trunk;6.前额动脉 prefrontal artery;7.中央前沟动脉 precentral sulcus artery;8.中央沟动脉 precentral sulcus artery;9.顶前动脉 anterior parietal artery;10.顶后动脉 posterior parietal artery;11.角回动脉 artery of angular gyrus;12.额叶 frontal lobe;13.颞叶 temporal lobe;14.侧脑室(已打开)lateral ventricle;15.岛叶 insular lobe;
M1~M5.大脑中动脉 M1~M5段 M1~M5 of MCA
图5-8 大脑中动脉(岛叶段)
1.外侧眶额动脉 external orbitofrontal artery;2.豆纹动脉 lenticulostriate artery;3.上干 superior trunk;4.中干 middle trunk;5.下干 inferior trunk;6.颞前动脉 anterior temporal artery;7.颞中动脉 middle temporal artery;8.颞后动脉 posterior temporal artery;9.中央沟动脉 precentral sulcus artery;10.顶前动脉 anterior parietal artery;11.顶后动脉 posterior parietal artery;12.角回动脉 artery of angular gyrus;13.岛叶 insular lobe;14.额叶 frontal lobe;
M1~M3.大脑中动脉 M1~M5 of MCA M1~M3段 M1~M3 of MCA
图5-9 大脑中动脉皮层支及穿支血管
1.大脑前动脉 anterior cerebral artery;2.外侧眶额动脉 external orbitofrontal artery;3.前额动脉 prefrontal artery;4.中央前沟动脉 precentral sulcus artery;5.中央沟动脉 precentral sulcus artery;6.顶前动脉 anterior parietal artery;7.顶后动脉 posterior parietal artery;8.角回动脉 artery of angular gyrus;9.颞枕动脉 occipitotemporal artery;10.颞后动脉 posterior temporal artery;11.颞中动脉 middle temporal artery;12.颞前动脉 anterior temporal artery;13.颞极动脉 temporal polar artery;14.小脑后下动脉 posterior inferior cerebellar artery;
M4.大脑中动脉 M4段 M4 of MCA
图5-10 大脑中动脉终末支
1.颈内动脉 internal carotid artery;2.大脑中动脉 middle cerebral artery;3.后交通动脉 posterior communicating artery;4.大脑后动脉 posterior cerebral artery;5.小脑上动脉 superior cerebellar artery;6.基底动脉 basilar artery;7.动眼神经 oculomotor nerve;8.视神经 optic nerve
图5-11 后交通动脉及其周边结构
1.后交通动脉 posterior communicating artery;2.脉络膜前动脉 anterior choroidal artery;3.大脑后动脉 posterior cerebral artery;4.小脑上动脉 superior cerebellar artery;5.颈内动脉海绵窦段 cavernous segment of ICA;6.颈内动脉床突上段supraclinoidal segment of ICA;7.大脑中动脉 middle cerebral artery;8.大脑前动脉 anterior cerebral artery;9.视神经 optic nerve;10.动眼神经 oculomotor nerve;11.滑车神经 trochlear nerve
图5-12 后交通动脉及其周边结构