The action potential spreads throughout the myocardium in the following sequence:

SA node  Atrial internodal tracts and atria  AV node  Bundle of His  Purkinje system  Ventricles

TLS Online TPP Program

#Id: 7213

#Unit 5. Developmental Biology

Class I presentation requires internal synthesis of virus protein, as shown by the requirement that the target cell be infected by live virus, and by the inhibition of class I presentation observed when protein synthesis was blocked by the inhibitor emetine

TLS Online TPP Program

#Id: 7214

#Unit 5. Developmental Biology

Class II presentation can occur with either live or replication-incompetent virus; protein synthesis inhibitors had no effect, indicating that new protein synthesis is not a necessary condition of class II presentation.

TLS Online TPP Program

#Id: 7215

#Unit 5. Developmental Biology

Class II, but not class I, presentation is inhibited by treatment of the cells with an agent that blocks endocytic processing within the cell (chloroquine).

TLS Online TPP Program

#Id: 7216

#Unit 5. Developmental Biology

T cell

TLS Online TPP Program

#Id: 7217

#Unit 5. Developmental Biology

T cells initiate the adaptive immune response by interacting MHC on antigen-presenting cells that have been exposed to pathogens. 

TLS Online TPP Program

#Id: 7218

#Unit 5. Developmental Biology

Development of T cells from hematopoietic stem cells on bone marrow stromal cells expressing the Notch ligand