What dysrhythmia is characterized by a sawtooth pattern of waves between normal QRS complexes on the ECG tracing?

The mucosa of the oral cavity and the rectum are simple columnar epithelium.

B and T lymphocytes can come and go from lymph nodes, but macrophages cannot.

Which of the following cells are not typically found in lymph nodes:

Vaccinations work  by exposing the adaptive immune system to a dead or weakened miro-organism causing the formation of Memory B and T lymphocytes.  

Which of the following DOES NOT occur in the stomach:

All of the following contribute to the lag time for the immune response EXCEPT:

Most digestion of all food groups occurs here:

Which of the following is FALSE regarding the anal sphincters:

A superficial cut involving the innate defenses only will not  result in immunity.