Biology by Khan Academy

Role of phagocytes in innate or nonspecific immunity | NCLEX-RN | Khan Academy

Role of phagocytes in innate or nonspecific immunity. Neutrophils, macrophages, and dendritic cells. MHC II. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/test-prep/nclex-rn/rn-immune-system/rn-the-…(link is external) Missed the previous lesson?

Role of the sarcoplasmic reticulum in muscle cells | NCLEX-RN | Khan Academy

The role of the sarcoplasmic reticulum in controlling calcium ion concentrations within the muscle cell. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/test-prep/nclex-rn/rn-muscular-system/rn-th…(link is external) Missed the previous lesson?