16. The double-layered membranous sac that encases and protects the heart, consisting of fibrous and serous layers, is referred to as the:

The process of blood cell formation is called:

What is the main function of white blood cells?

The liquid portion of blood is known as:

Which part of the respiratory center in the brain primarily controls the rhythmic pattern of breathing?

Which organ is primarily responsible for producing erythropoietin, the hormone that stimulates red blood cell production?

48. Which is NOT a normal function of the lymphatic system?

Which of the following describes an autoimmune disease?

13. The coronary arteries are primarily responsible for delivering oxygenated blood to which of the following structures?

21. Which of the following factors most significantly affects vascular resistance, thereby influencing blood flow and arterial pressure within the circulatory system?