What structures prevent the backflow of lymph in lymphatic vessels?

Correct Answer: A

Rationale: Valves in lymphatic vessels prevent backflow; muscles aid movement but don't prevent it, capillaries collect lymph, and arterioles are blood vessels.

Correct Answer: C

Rationale: The splenic artery supplies the spleen; renal , hepatic , and mesenteric supply other organs.

Correct Answer: A

Rationale: Lacteals in the small intestine absorb fats; spleen , nodes , and thymus don't.

Correct Answer: A

Rationale: Lymphadenitis is node inflammation; lymphangitis is vessels, lymphoma is cancer, lymphedema is swelling.

Correct Answer: C

Rationale: Lymph nodes store memory cells; thymus matures, spleen filters, tonsils trap.