The brain is the center of the nerv

The brain is the center of the nervous system in all vertebrate and most invertebrate animals. Some primitive animals such as jellyfish and starfish have a decentralized nervous system without a brain, while sponges lack any nervous system at all. In vertebrates the brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing, balance, taste, and smell.
Brains can be extremely complex. The cerebral cortex of the human brain contains roughly 15–33 billion neurons, perhaps more, depending on gender and age, linked with up to 10,000 synaptic connections each. Each cubic millimeter of cerebral cortex contains roughly one billion synapses. These neurons communicate with one another by means of long protoplasmic fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body and target them to specific recipient cells.
The brain controls the other organ systems of the body, either by activating muscles or by causing secretion of chemicals such as hormones and neurotransmitters. This centralized control allows rapid and coordinated responses to changes in the environment. Some basic types of responsiveness are possible without a brain: even single-celled organisms may be capable of extracting information from the environment and acting in response to it. Sponges, which lack a central nervous system, are capable of coordinated body contractions and even locomotion. In vertebrates, the spinal cord by itself contains neural circuitry capable of generating reflex responses as well as simple motor patterns such as swimming or walking. However, sophisticated control of behavior on the basis of complex sensory input requires the information-integrating capabilities of a centralized brain.
Despite rapid scientific progress, much about how brains work remains a mystery. The operations of individual neurons and synapses are now understood in considerable detail, but the way they cooperate in ensembles of thousands or millions has been very difficult to decipher. Methods of observation such as EEG recording and functional brain imaging tell us that brain operations are highly organized, while single unit recording can resolve the activity of single neurons, but how individual cells give rise to complex operations is unknown.

Kết quả (Trung) 1:

大脑是中枢神经系统中所有的脊椎动物和无脊椎动物最动物的中心。一些原始的动物，如水母和海星有分散的中枢神经系统无需大脑，而海绵根本缺乏任何中枢神经系统。在脊椎动物中大脑位于头部，受保护的由头骨和接近主的感觉器官的视觉、 听觉、 平衡、 味道，和气味。大脑可以极其复杂。人类大脑的大脑皮层包含约 150 亿神经元，也许更多，性别和年龄，联系在一起达 10,000 突触连接。每立方毫米的大脑皮质包含大约 10 亿突触。这些神经元长原生质纤维称为神经轴突，运送火车叫去很远地方的大脑或者身体的动作电位的信号脉冲通过互相沟通并设定这些链接到特定收件人的单元格。大脑控制身体的其他器官系统激活肌肉或导致分泌的化学物质如激素和神经递质。这种集中式的控制允许快速和协调对环境变化的反应。一些基本类型的响应速度是可能的没有大脑： 即使单细胞有机体可能能够从环境中提取信息并采取行动对此作出回应。海绵，缺乏中枢神经系统，有能力协调的身体收缩和甚至运动。在脊椎动物中，脊髓本身包含神经电路能够产生反射性的反应，以及简单的运动模式，如游泳或散步。然而，复杂的行为的控制和复杂的感觉输入的基础上要求中央大脑的信息集成的能力。尽管科技进步迅速，很多关于大脑是如何工作的一个谜。操作的单个神经元和突触现在理解相当详细，但他们合作在合奏的数以千计或数以百万计的方式已很难破译。方法观察如脑功能成像和脑电图进行记录告诉我们大脑操作高度组织，同时单胞外记录可以解决单个神经元的活性但如何个别细胞会引起复杂的操作是未知。

Kết quả (Trung) 3:

大脑是在所有的脊椎动物，无脊椎动物神经系统的中心。一些原始的动物，如水母、海星有分散的神经系统没有大脑，而海绵没有任何神经系统在所有。在脊椎动物脑位于头，由颅骨保护，靠近主要感觉器官视觉，听觉，味觉平衡，和气味。
大脑可以是非常复杂的。人类的大脑含有大约15–33000000000个神经元，大脑皮层，也许更多，这取决于性别和年龄，高达10000的突触连接，每个连接。大脑皮层每立方毫米包含大约十亿个突触。这些神经元与另一个长原生质纤维称为轴突的方式进行通信，它携带的信号脉冲称为动作电位的大脑或身体和针对他们特定的受体细胞的遥远的地方的火车。
大脑控制身体的其他器官系统，无论是通过激活肌肉或造成的化学物质如激素和神经递质的分泌。这种集中控制，允许快速和协调在环境变化的响应。反应的一些基本类型是可能的：即使没有大脑的单细胞有机体能够从环境和动响应它的信息提取。海绵，缺乏一个中央神经系统，能够协调的身体收缩甚至运动。在脊椎动物中，脊髓本身就包含着能够产生反射反应，如游泳或散步的简单运动模式的神经回路。然而，在复杂的感觉输入的基础上的行为复杂的控制要求的信息整合能力，中央大脑的
尽管科技进步迅速，很多关于大脑如何工作仍然是一个谜。单个神经元和突触的业务现在相当详细的了解，但是他们在数千或数百万合奏已破译合作是非常困难的。观察方法如脑电图记录和脑功能成像的告诉我们，大脑运作是高度有组织的，而单单元记录可以解决单个神经元的活动，但有单个细胞产生复杂的操作是未知的。