The SA nodes functions first for setting pace for the heart, then the inter-nodal pathway make link b/w SA and AV node. AV node is site of delay when contraction of atria occurs. AV bundle is the mean of electrical link b/w atria and ventricle. The conveying of impulse to the inter-ventricular septum occurs through bundle branches, while conveying of impulse throughout and along the walls of ventricle occurs through Purkinje fibers.
The major function of the immune system is to protect the host from environmental agents such as microbes or chemicals, thereby preserving the integrity of the body. This is done by the recognition of self and response to non-self.
