Sensitivity to animal-derived immune serum may lead to a serious condition called:

A. The inguinal lymph nodes are not part of the hepatic portal system. The hepatic portal system refers to the venous system that directs blood from the digestive organs to the liver, while the inguinal lymph nodes are involved in immune function.
B. The inguinal lymph nodes do not line the entrance of the spleen. The spleen is located in the upper left abdomen and has its own set of immune cells but does not directly connect to the inguinal lymph nodes.
C. The inguinal lymph nodes are located in the groin area. They are part of the body's lymphatic system and help filter lymph fluid from the lower extremities and genital region.
D. Kupffer cells are specialized macrophages found in the liver, not in the inguinal lymph nodes. These cells are involved in the filtration of blood and the removal of pathogens and debris.

A. They have thin walls – Lymphatic vessels have thin walls, similar to veins, which allow for the passage of lymph.
B. They can contract to propel lymph – Lymphatic vessels do have the ability to contract, aided by smooth muscle and valves, which helps propel lymph in the right direction.
C. They transport lymph to the tissues – This statement is incorrect. Lymphatic vessels carry lymph away from the tissues (not to the tissues) and toward lymph nodes and eventually to the bloodstream.
D. They are blind-ended – Lymphatic capillaries are indeed blind-ended, meaning they begin as closed-ended tubes that absorb interstitial fluid from tissues.