7 Arterial Supply of the Spinal Cord Neuroanatomy 7 Dr Ahmed Kamal — Transcript

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1. 0:03The arterial supply of the spinal cord
2. 0:07is the first or a recurring question in
3. 0:10written exams. In all medical schools,
4. 0:14which is why it is memorized well.
5. 0:16Fortunately, it is very easy. The
6. 0:20spinal cord is supplied by an anterior
7. 0:24spinal artery, two posterior spinal
8. 0:28arteries, and radicular arteries. Pay
9. 0:33attention to this with me. Here is the
10. 0:36spinal cord. We find in the anterior
11. 0:39median fissure here an artery running
12. 0:41along the spinal cord. This is called
13. 0:44the anterior spinal artery. Then around
14. 0:47the spinal cord, posterior roots and
15. 0:49anterior roots emerge from it. Around
16. 0:53the posterior root, there is a
17. 0:55posterior spinal artery here. And here
18. 0:58is a posterior spinal artery running
19. 0:59along the spinal cord. And here is a
20. 1:01posterior spinal artery, and here is a
21. 1:03posterior spinal artery. So, there are
22. 1:06posterior spinal arteries here. Because
23. 1:08there are four, two on this side and
24. 1:10two on the other side, running along
25. 1:11the spinal cord. Then there are
26. 1:14arteries that come. This is the spinal
27. 1:17nerve here. This is a posterior root
28. 1:20and this is an anterior root. This
29. 1:22spinal nerve exits from the foramen
30. 1:24between the vertebrae. It is called the
31. 1:26intervertebral foramen. With the exit
32. 1:30of each spinal nerve, an artery enters.
33. 1:32This artery is called a radicular
34. 1:35artery. So, a radicular artery enters
35. 1:37here. And a radicular artery also
36. 1:40enters here. This radicular artery that
37. 1:42enters with the spinal nerve is called
38. 1:43radicular. The radicular artery forms
39. 1:46an anastomosis with the anterior spinal
40. 1:50artery and the posterior spinal artery.
41. 1:52And here it forms an anastomosis with
42. 1:54the anterior spinal artery. On the
43. 1:55other side, the radicular artery also
44. 1:57gives off a branch. It forms an
45. 1:59anastomosis with the posterior spinal
46. 2:00arteries. And from this side, it forms
47. 2:02an anastomosis with the anterior spinal
48. 2:04artery. All these arteries together
49. 2:07form an anastomosis. They form a circle
50. 2:10around the spinal cord. And from this
51. 2:12circle around the spinal cord, the
52. 2:14blood supply starts. Which enters to
53. 2:18provide blood supply to the spinal cord
54. 2:19. So I have here these are the arteries
55. 2:22that provide blood supply to the spinal
56. 2:24cord. So when someone asks me, what are
57. 2:26the arteries that supply blood to the
58. 2:28spinal cord? I tell them there is an
59. 2:29anterior spinal artery. Where does this
60. 2:31anterior spinal artery come from? He
61. 2:34said, here is the spinal cord, and this
62. 2:37is the spinal cord, and this is the
63. 2:39medulla oblongata. And above the
64. 2:41medulla is another part of the brain
65. 2:43called the pons. Here there is an
66. 2:45artery called the vertebral artery and
67. 2:46this is a vertebral artery. Both
68. 2:48together, after they finish the medulla
69. 2:50, come to the pons to form the basilar
70. 2:52artery. So here, from the vertebral
71. 2:54artery, the anterior spinal emerges.
72. 2:56From the vertebral artery, the anterior
73. 2:57spinal emerges. They bring out the
74. 2:59anterior spinal which runs in this
75. 3:01anterior median sulcus. So this is the
76. 3:03anterior spinal artery, a branch from
77. 3:05the vertebral artery. We come next to
78. 3:07the two posterior ones on both sides.
79. 3:09Yes, they come here; if there is one
80. 3:11here, here is a posterior spinal artery
81. 3:14and the posterior. This spinal artery
82. 3:16splits into two, one here and one here.
83. 3:18And on the other side, one here and one
84. 3:20here. So these are the two posterior
85. 3:22spinal arteries. On every side, they
86. 3:25are also coming from the vertebral
87. 3:27artery. So the spinal artery is coming
88. 3:30from. The vertebral, and the two
89. 3:31posterior ones are coming from the
90. 3:33vertebral. And we are left with the
91. 3:35radicular arteries that enter with the
92. 3:37spinal nerves. Let's see the next slide
93. 3:39. Here it is clear, this is the
94. 3:41anterior spinal artery, which is this
95. 3:44one. And these two are what are called
96. 3:46the posterior spinal arteries, one here
97. 3:48and one there. They divide into two.
98. 3:50Here are the posterior spinal arteries,
99. 3:52and two posterior spinal arteries
100. 3:54around the posterior root, see. Then
101. 3:56the radicular. Artery entered with the
102. 3:59spinal nerve and distributed, see. So
103. 4:01now there is an anterior radicular
104. 4:02artery and a posterior radicular artery
105. 4:04. Here is an anterior radicular artery,
106. 4:06and here is a posterior radicular
107. 4:07artery. All these arteries formed a
108. 4:10circle together. And they started to
109. 4:13provide blood supply to the spinal cord
110. 4:15. The anterior spinal artery is a
111. 4:17branch from the vertebral, which is
112. 4:19this one. This is the anterior spinal
113. 4:21artery, a branch from the vertebral.
114. 4:23And the posterior spinal artery is also
115. 4:25a branch from the vertebral. Here, this
116. 4:27view is clear. Look, this is the
117. 4:30anterior spinal artery here. This is
118. 4:32the spinal cord. This is the anterior
119. 4:33spinal artery here. And these are the
120. 4:36radicular ones here. These radicular
121. 4:38arteries enter with the spinal nerve.
122. 4:40See, it entered with the spinal nerve.
123. 4:42Radicular artery. And here, the spinal
124. 4:43nerve radicular artery entered. And
125. 4:45here is a radicular artery. The
126. 4:46radicular artery divides into two here.
127. 4:48And it anastomoses with the posterior
128. 4:50spinal arteries. And all these
129. 4:52anastomoses provide blood supply to the
130. 4:54spinal cord. So, we will also talk and
131. 4:56say that the blood supply of the spinal
132. 4:58cord. Depends on the anterior spinal
133. 5:00artery, this one from that artery. And
134. 5:03two posterior spinal ones from the
135. 5:05artery as well. And the radicular
136. 5:07arteries, which we will see now, where
137. 5:09these radicular arteries come from. So
138. 5:12we will see now, here is the radicular.
139. 5:14Pay attention with me to this drawing.
140. 5:16This drawing has this long spinal cord,
141. 5:20all of it. This is the spinal cord
142. 5:22descending here. Here, this is the
143. 5:25vertebral artery coming to give it
144. 5:27blood supply, and then. It gives it the
145. 5:29anterior spinal artery that descends
146. 5:31downwards. And there should be two
147. 5:33posterior spinal arteries behind. Here,
148. 5:35with every segment of the spinal cord,
149. 5:37a radicular artery enters from here.
150. 5:39And a radicular artery here. And a
151. 5:41radicular artery here. And a radicular
152. 5:42artery here. And a radicular artery
153. 5:44here. Meaning they enter the spinal
154. 5:46cord with the spinal nerves. Each
155. 5:49segment has a radicular artery on each
156. 5:51side. So here is the radicular artery,
157. 5:53coming with the spinal nerve. And a
158. 5:54radicular artery here, also coming with
159. 5:56the spinal nerve. And the radicular
160. 5:57artery coming with the spinal. So these
161. 5:59radicular arteries, they enter with the
162. 6:01number of spinal nerves. Well, where do
163. 6:04they enter from? They say they come
164. 6:05from the nearest arteries to them,
165. 6:07meaning branches. The radicular
166. 6:09arteries, their number is large, 31
167. 6:12arteries. Like the spinal cord with the
168. 6:14number of its segments, 31. Segments.
169. 6:18So here I see that the radicular
170. 6:20arteries arise either from the
171. 6:21vertebral artery. Meaning here in the
172. 6:23neck, they arise from the vertebral.
173. 6:26They are considered branches of the
174. 6:27vertebral artery. Here is the vertebral
175. 6:29artery, it gives. Although it gave the
176. 6:32anterior and posterior spinal arteries,
177. 6:34it can also give a radicular artery.
178. 6:36Number two, it arises from the
179. 6:38ascending cervical artery. And it
180. 6:41arises from the superior intercostal
181. 6:43arteries. Remember the ones in the
182. 6:45thorax? The superior intercostal
183. 6:47arteries also provide radicular
184. 6:48arteries. The posterior intercostal
185. 6:50artery. The intercostal arteries, which
186. 6:54we also saw in the thorax, they give.
187. 6:56Arteries, the intercostal artery gives
188. 6:59a radicular. The lumbar arteries in the
189. 7:01lumbar region, which arise from the
190. 7:03abdominal aorta. They also supply the
191. 7:06radicular arteries. The lateral sacral
192. 7:09arteries, these are also sacral
193. 7:12arteries. They provide blood supply to
194. 7:16the radicular arteries, or give
195. 7:18radicular arteries entering the spinal
196. 7:20cord. So, once we know the anterior
197. 7:24spinal artery arises from the vertebral
198. 7:26. The posterior spinal arteries also
199. 7:29arise from the vertebral. As for the
200. 7:31radicular arteries, they arise from
201. 7:33many arteries. In the head and neck,
202. 7:35they arise from the vertebral artery.
203. 7:36From the ascending cervical. From the
204. 7:38subcostal in the thoracic region. They
205. 7:41arise from the intercostal arteries and
206. 7:43the subcostal artery. In the lumbar
207. 7:46region or in the abdomen. They arise
208. 7:47from the lumbar arteries and the
209. 7:49lateral sacral. All of these supply the
210. 7:52spinal cord.