1. Transport in Humans The Blood Circulatory System

3. Describe the structure and function of the heart in moving blood around the body.

4. Describe the structure and function of the blood vessels.

6. Blood pumped by the heart leaves the open-ended vessels for a series of blood spaces surrounding the tissues.

7. When the heart relaxes, the blood flows back into the vessels through pores.

9. The circulating fluid does not leave the blood vessels or come in direct contact with the blood tissues at any time.

11. The systemic circulation connects the heart and all the body tissues except the lungs. It is responsible for transporting:

12. Nutrients from the digestive system to the tissues that need the food.

13. Regulatory substances from various organs and glands to the sites where the hormone will take effect.

15. Nutrients from the digestive system,

16. Oxygen from the lungs,

17. Carbon dioxide and other wastes from tissue cells,

19. 9.2 The Pump: The Heart

21. The membranes of the muscle tissue enable ions to diffuse rapidly across them.

29. Family history of heart disease;

30. Being a male;

31. Age;

32. Smoker;

33. High intake of saturated fats and salt;

34. Lack of exercise;

35. High blood pressure;

36. Intake of excessive sugars;

38. The presence of valves between the atria and ventricles, and at the entrance of the pulmonary artery and aorta ensures that the flow of blood in the heart is in one direction.

39. Both atria contract at the same time, pushing blood into the ventricles.

41. The beating of the heart forcing the blood out into the arteries gives rise to the pulse.