Wednesday, April 27, 2011

Physiology- Development and plasticity of brain

正当大家都在埋头苦干的 读书时,我的心,不小心飞进了这里。。。很用心的让自己心静静的读,静静地吸收所读的,但最后我还是来到了这里,写下我心情。。。

我没有像朋友那样的勤力,老早就开始背书。多两天要考的,我今晚才开始翻。师兄问:“你读到哪里?”,我说“刚要开始”,他问:“你是不是想死?”,我说“不是。。。”。

就这样我开始了我的第一课,第一章。。。

Development and plasticity of brain

- Plasticity of the brain refer the idea that brain is constantly changing throughout the lifetime.
- Prefrontal cortex develops rapidly btw 7 to 12 months.
- The human CNS begins to form when the embryo is approximately 2 weeks old.
  • The dorsal surfface thickens forming a neural tube surrounding a fluid filled cavity.
  • The forward end enlarges and differentiates into the hindbrain, midbrain, and forebrain.
  • The rest of the neural tube becomes the spinal cord.
- The development of neurons in the brain involves the following 4 processes (重要) :
  1. Proliferation: to the production of new cells/neurons in the brain primarily occurring early in life. In early development, cell lining the ventricles divide. Somes cells become stem and some continue to divide. Others remain where they are or become neuron or glia that migrate to other location. Migration: the movement of the newly formed neurons and glia to their eventual location. Migration occur in a variety of directions throughout the brain. Migration occur via cell following chemical paths in the brain of immunoglobins and chemokines.
  2. Differentiation: the forming of the axon and dentrite that gives the neuron its distinctive shape. The axon grows 1st either during migration or once it has reached target and is followed by the development of the dendrites. Neurons differ in their shape and chemical component depending on their location in the brain.
  3. Myelination: process by which glia produce the fatty sheath that covers the axons of some neurons. Myelin speeds up the transmission of the neural impulses. Myelination 1st occurs in the spinal cord and then in the hindbrain, midbrain and forebrain.
  4. Synaptogenesis: final stage of neural development and refers to the formation of the synapses btw neurons. Occurs throughout the life as neurons are constantly forming new connections and discarding old one.
- FAS is a condition that children are born with if the mother drinks heavily during pregnancy.
  • Hyperactivity and impulsiveness
  • difficulty maintaining attention
  • varying degree of mental retardation
  • motor problem and heart defects
  • facial abnormalities
- Part of the mechanism on increased ability due to experience is that attention to anything releases dopamine. Dopamine acts on the cortex to expand the response to stimuli active during the dopamine release.

- Possible causes of brain damage:
  • Tumor
  • infection
  • exposure to toxic substance
  • degenerative diseases
  • closed head injuries
- Types of stroke include:
  1. Ischemia
  2. Hemorrhage
- Both types of stroke cause by Edema.
- Treatment for stroke:
  1. tissue Plasminogen activation (tPA)
  2. cooled brain
  3. Cannabanoids
  4. Diaschisis
em。。。已经不知道自己读到哪里了,迷失了方向!今晚到此结束。。。


2 comments:

  1. 哪个师兄来的jek?hehe。。。XD

    好过我了。。。我到现在,一粒字都还没有读到。
    我真的要死掉料。。。>.<

    ReplyDelete
  2. 是光兄。

    我读的这课,已经20分了。。。
    也不懂考了什么东东。没有 不及格就好了。。

    你还是去读书啦。。。

    ReplyDelete