Created by Sal Khan. Correction to "Sodium-potassium pump" video.

Created by Sal Khan. 钠钾泵 Sodium-potassium pump

Created by Sal Khan. 神经元的结构 Anatomy of a neuron

Created by Sal Khan. 神经元膜电位的两种不同类型的变化。 Two different types of changes in the membrane potential of a neuron.

Created by Sal Khan. 炎症反应（红肿热痛）的机制 Overview of the inflammatory response.

Created by Sal Khan. B 细胞、CD4+ T 细胞和 CD8+ T 细胞的回顾。 Review of B cells, CD4+ T cells and CD8+ T cells.

Created by Sal Khan. How cytotoxic T cells get activated by MHC-I/antigen complexes and then proceed to kill infected cells. 1.MHC I 2.细胞毒性T细胞

Created by Sal Khan. Introduction to helper T cells and their role in activating B cells. 1.复习 2.T细胞 3.辅助T细胞的激活 4.效应T细胞的作用 5.T细胞对B细胞的激活

Created by Sal Khan. 1.MHC II （主要组织相容性复合体） 2.antigen presenting cells (APCs) （抗原提呈细胞）

Created by Sal Khan. Overview of B cells (B lymphocytes) and how they are activated and produce antibodies. 1.B细胞作用机制 2.膜结合抗体 3.记忆B细胞，效应B细胞

Created by Sal Khan. Innate vs. adaptive immunity. Humoral adaptive immunity vs. cell-mediated adaptive immunity. 1.特异性免疫和非特异性免疫 2.体液免疫和细胞免疫

Created by Sal Khan. Role of phagocytes in innate or nonspecific immunity. Neutrophils, macrophages, and dendritic cells. MHC II. 1.解释免疫系统 2.免疫系统的第一道，第二道防线 3.吞噬细胞的作用机制

Created by Sal Khan. 跳跃式传导 Myelin sheaths, nodes of Ranvier, and saltatory conduction in neurons.

Created by Sal Khan. 一个神经元如何在化学突触处刺激（或抑制）另一个神经元。 How one neuron can stimulate (or inhibit) another neuron at a chemical synapse.

Created by Sal Khan. 肌球蛋白和肌动蛋白是怎么相互作用使肌肉收缩的

Created by Sal Khan. 原肌球蛋白和肌钙蛋白的作用，他们是怎么调节肌肉收缩的

Created by Sal Khan. 肌浆网的作用

Created by Rishi Desai. Rishi is a pediatric infectious disease physician and works at Khan Academy. 波尔效应和霍尔登效应

Created by Rishi Desai. Rishi is a pediatric infectious disease physician and works at Khan Academy. 氧含量 CaO2 氧饱和度SaO2 氧分压PaO2

Created by LeBron James, Sal Khan.