Re: 脑 (1)

由 xw » 7月 25 2011

老虻叔说举一漏万，就大脑的结构与名称，可列的名词就多如大海，还不说性能与
内部物理化学机制，腺体液流血脉氧料养料。有人说此题目应称人脑，维基中文说
瑞脑，习惯称大脑，我也选不好。其实人脑上面提的Brain stem, 脑干，中脑脑桥
与延髓，就是整个爬行类动物的脑子了。所以英文又称The Reptilian Brain:

In primitive animals, this is just about all the brain there is. All the other
parts we’ve taled about in the human brain just don’t exist for them. This
is why your brain stem is sometimes referred to as the “reptilian brain,” 
because it’s the main part of the brain in creatures such as lizards, turtles
, and fishes. 

脑干（中脑、桥脑、延髓）上接间脑diencephalon(“interbrain”) 、下接脊髓，负
责调节复杂的反射活动，包括调节呼吸作用、心跳、血压等，对维持机体生命有重
要意义。12对脑神经之中除了嗅神经和视神经外，脑干含有动眼神经、滑车神经、
三叉神经、展神经、面神经、前庭蜗神经、舌咽神经、迷走神经、副神经及舌下神
经这10对处理脑神经讯息的神经核。因此，医学常以「脑干死亡」为一个人类失去
生命的标准。

The brain stem is also like a pole on which parts of the brain are hung.
In addition to all of the pieces attached to it, most of the big nerves in 
your head, called the cranial nerves, run through the brain stem. These
nerves are responsible for all of the movements in your head, from the 
movement of your eyes to the way you swallow your food.

Human brainstem-thalamus posterior view description.JPG

Human brainstem and thalamus(丘脑) – posterior view

1. Taenia choroidea (and lateral: Lamina affixa, Stria terminalis)
2. Thalamus, Pulvinar thalami
3. (Ventriculus tertius)
4. Stalk of Glandula pinealis
5. Habenula
6. Stria medullaris
7. Colliculus superior
8. Brachium colliculi superioris
9. Colliculus inferior
10. Brachium colliculi inferioris
11. Corpus geniculatum mediale
12. Sulcus medianus
13. Pedunculus cerebellaris superior
14. Pedunculus cerebellaris inferior
15. Pedunculus cerebellaris medius
16. Tuberculum anterius thalami
17. Obex, Area postrema

A: Thalamus, B: Mesencephalon, C: Pons, D: Medulla oblongata

Human brainstem – mesencephalon (from the Greek mesos – middle, 
and enkephalos – brain)

中脑长约1.5公分，其腹面由桥脑延伸至间脑的乳头体，在两侧明显的突起称基脚
（basis pedunculi），是由锥体运动系统及皮质桥脑径的纤维所组成。位于基脚之
间的深陷处称为脚间窝（interpeduncular fossa），在脚间窝的底剖，有很多小血
管穿入中脑。因于脚间窝的底部，又称为后穿孔质。动眼神经起始于脚间窝的两侧。
中脑的侧面主要是大脑脚。大脑脚包括一些内部构造如黑质（substantia nigra）
和背盖（tegmental）。中脑的背面有四个圆形的隆起：上丘（superior colliculi）
和下丘（inferior colliculi）又称为四叠体（corpora quadrigemina）。下丘是
听觉的转运站。上丘与眼球的随意运动及视觉或其它刺激引起的眼球与头部运动有
关。

It’s at the top of the brain stem and is shaped a little like a hook. It 
contains nerves that send information from the eyes and ears to the 
thalamus(丘脑). It also controls head and eye movement, two of the most 
important movements in your entire body. Because of this, the midbrain 
has more motor nerves than any other section of your central nervous 
system.

中脑最酷的事情就是晚上睡觉的时候为你屏弃外面世界，就象把一扇身体的门关闭。
睡觉的时候，中脑几乎不允许外面刺激进入脑内，除非是巨大的刺激，巨声如打雷，
闪电，床头的灯亮，或有物触碰，人拉抓压你的身体四肢。

中脑内部结构也很复杂，网上找不到一幅好的示意图，暂按维基列名：

mesencephalon – Midbrain

1. tectum
   1. inferior colliculi
   2. superior colliculi
2. mesencephalic duct (cerebral aqueduct, Aqueduct of Sylvius)
3. cerebral peduncle
   1. interpeduncular nucleus
4. midbrain tegmentum
   1. ventral tegmental area
   2. Red Nucleus
   3. crus cerebri
   4. substantia nigra
5. pretectum

顶盖部: 四叠体 (下丘, 上丘) · 联合下器官 · 顶盖前 

大脑脚被盖部: 中脑导水管周围灰质 (中脑水管, 中缝背核) · 腹侧被盖 · 脑桥
脚核 · 红核 · 内侧纵束 (内侧纵束吻侧间质核) · 丘系 (内侧丘系, 外侧丘
系) · 颅神经核群 (III：动眼神经核, III：Edinger-Westphal核, IV：滑车神经
核, V：三叉神经中脑核) 

大脑脚基部: 黑质 · 大脑脚 (皮质脊髓束, 皮质延髓束, 皮质脑桥束/额桥束) 

Right below midbrain is a bulging mass, like a swollen throat, called pons
. The pons connects the cerebral cortex above the brain stem to the 
medulla oblongata below it. Scientists have found that the pons is what 
sends you into rapid eye movement, or REM, sleep, the phase of sleep 
when you dream.

Diagram showing the positions of the three principal subarachnoid cisternæ 
(pons visible at center)

桥脑又称脑桥，是人和哺乳动物小脑腹面的特有构造。

脑桥在延脑的上方，它位于延髓与中脑的大脑脚之间，前后缘有横沟为界；外形呈
白色弓状的横隆凸；内部有大量的横走的神经纤维，连接左、右小脑半球，并有许
多纵走的神经纤维束，联系端脑、间脑、中脑、延髓和脊髓，在神经纤维束之间有
许多神经核。

脑桥对于人的睡眠具有调节和控制的作用。

A number of cranial nerve nuclei are present in the pons:

• mid-pons: The chief or pontine nucleus of the trigeminal nerve sensory nucleus (V)
• mid-pons: the motor nucleus for the trigeminal nerve (V)
• lower down in the pons: abducens nucleus (VI)
• lower down in the pons: facial nerve nucleus (VII)
• lower down in the pons: vestibulocochlear nuclei (vestibular nuclei and cochlear nuclei) (VIII)
• Superior salivatory nucleus

Functions of these four nerves include sensory roles in hearing, equilibrium, 
and taste, and in facial sensations such as touch and pain; as well as motor 
roles in eye movement, facial expressions, chewing, swallowing, urination, 
and the secretion of saliva and tears.

还有呼吸自动调节的中枢：
Respiratory centres 

• pneumotactic centre
• apneustic centre

to be continued…