The vessels that carry blood to the heart from the lungs are?.

Choice A rationale:

Veins do not always carry deoxygenated blood. The pulmonary veins are an exception as they carry oxygenated blood from the lungs to the heart.

Choice B rationale:

Veins do not carry blood away from the heart. They carry blood back toward the heart.

Choice C rationale:

Veins do not have a thick tunica media. The tunica media is thinner in veins than in arteries.

Choice D rationale:

Veins have valves. This is a true statement. The valves in veins prevent blood from flowing backward.

Choice A rationale:

Peyer’s patches are lymphoid nodules located in the small intestine and play a role in immune surveillance of the intestinal lumen and in the facilitation of the immune response.

Choice B rationale:

The appendix serves as a reservoir for beneficial gut bacteria. It is a narrow pouch that projects off the cecum in the digestive system.

Choice C rationale:

Adenoids are not known to serve as a reservoir for beneficial gut bacteria. They are located in the upper part of the throat and are part of the immune system, helping to fight off infections and trap bacteria that enter through the nose.

Choice D rationale:

Tonsils are not known to serve as a reservoir for beneficial gut bacteria. They are lymphoid tissues located at the back of the throat and help protect the body from respiratory infections.