Which of the following is (are) found in many veins that help direct blood flow in one direction only: toward the heart?
A) valves
B) lymph nodes
C) myocardium
D) pericardium

Question

Quizplus · Accepted Answer

Valves are found in many veins to prevent the backflow of blood and direct it towards the heart. Lymph nodes, myocardium, and pericardium are not directly involved in directing blood flow in veins.

Which of the Following Is (Are) Found in Many Veins