_____ are areas where arteries lie close to the body surface and a pressure wave caused by the expansion and recoil of arteries can be felt.

550 nm electromagnetic radiation is in what region of the electromagnetic spectrum?

_____ produce plasma cells which secrete antibodies.

_____ cells produce fibers that support other cells in lymphoid organs.

On an electrocardiogram, the P wave corresponds with which of the following electrical events?

Which of the following lymphoid structures gather and remove pathogens from food and air?

Around 80% of the volume of blood in the ventricles fills passively; the other 20% depends on _____.

The _____, in the wall of the distal portion of the small intestine are important for destroying bacteria that might try to breach the intestinal wall AND for sampling the gut flora to generate “memory” lymphocytes.

Which of the following acts as the “backup” pacemaker to the heart and is responsible for a 0.1 second delay in impulse transmission?

A blood clot that develops in an unbroken blood vessel and freely floats in the blood stream is known as a: