Explore a 21-minute video lecture on helper T cells and their crucial role in activating B cells as part of the immune system physiology. Gain a comprehensive understanding of the adaptive immune system, focusing on T cells, cytotoxic T cells, naive helper T cells, and effector helper T cells. Learn from Sal Khan's clear explanations and visual aids to prepare for the NCLEX-RN exam. Access additional resources, including related lessons on cytotoxic T cells and professional antigen-presenting cells, to further enhance your knowledge of immunology. Benefit from Khan Academy's free, high-quality educational content, designed to support self-paced learning in various subjects, including biology and healthcare.