1. THE CARDIORESPIRATORY SYSTEM Chapter 9

2. Cardiorespiratory System  What are the functions of the cardiorespiratory system? –Transport O 2 to tissues and removal of waste –Transport of nutrients to tissues –Regulation of body temperature

3. Cardiorespiratory System  What are the components of the cardiorespiratory system?  Cardio- Heart = a pump between external and internal respiration Blood Vessels = transportation  Respiratory Lungs = gas exchange

5. Cardiovascular System  Heart  Blood vessels

6. THE HEART PULMONARY CIRCUIT SYSTEMIC CIRCUIT

7. THE HEART  Four chambers  Right atria - blood from systemic system to...  Right ventricle - blood to pulmonary system and then to...  Left atria - blood from pulmonary system to...  Left ventricle - blood to systemic system and then to...  Right atria (and repeat)

8. Cardiovascular System Systemic circuit  Which side of the heart is part of the systemic circuit?  What is the oxygen content of the blood (high or low)?  Which chamber of the heart does the blood return into? Pulmonary circuit  Which side of the heart is part of the systemic circuit?  What is the oxygen content of the blood (high or low)?  Which chamber of the heart does the blood return into?

9. Blue section shows blood flow through the right side of the heart Red section shows blood flow through the left side of the heart BLOOD FLOW THROUGH THE HEART

10. MYOCARDIUM or Cardiac Muscle  What is the myocardium?  Why is the left ventricle the most powerful and largest of the chambers?  Note: Thickness varies directly with stress placed on chamber walls. With vigorous exercise, the left ventricle size increases. Right Left Wall

11. MYOCARDIUM Cardiac Muscle  Intercalated disks  What are they?  What is their function?

12. CONTROL OF THE HEART - INTRINSIC

13.  What part of the heart is referred to as the pacemaker of the heart?  What is the function of the A-V node?  What is an electrocardiogram?

14. Electrocardiogram (ECG or EKG)  Terms Depolarization: stimulation of the myocardium Repolarization: recovery of the myocardium from stimulation

15. CONTROL OF THE HEART - ECG

16. Assignment Questions from Chapter 9  What are the functions of the cardiorespiratory system?  What are the components of the cardiorespiratory system?  Which side of the heart is part of the systemic circuit?  What is the oxygen content of the blood (high or low)?  Where does the blood flow to at the end of the systemic circuit?  Which side of the heart is part of the pulmonary circuit?  What is the oxygen content of the blood (high or low)?  Where does the blood flow to at the end of the pulmonary circuit?  What is the myocardium?  Why is the left ventricle the most powerful and largest of the chambers?  What are intercalated disks?  What is the function of intercalated disks?  What part of the heart is referred to as the pacemaker of the heart?  What is the function of the A-V node?  What is an electrocardiogram?

17. CONTROL OF THE HEART - EXTRINSIC  Medulla – control center  Neural input to medulla Higher brain centers Baroreceptors (blood vessels) Stretch receptors (heart) Chemoreceptors (blood vessels) Mechanoreceptors (muscles/joints)  The medulla can alter speed of contraction (heart rate) and/or force of contraction (stroke volume)

18. CONTROL OF THE HEART - EXTRINSIC

19. Parasympathetic Nervous System acts through the vagus nerve. What affect does the vagus have on heart rate? What affect does the Sympathetic Nervous System have on heart rate? What affect do the hormones epinephrine and norepinephrine have on heart rate?

20. HEART FUNCTION  When the energy needs of the body increase, what happens to the heart rate?  How else can the heart supply more blood to the body?

21. HEART FUNCTION - Heart Rate Heart Rate  Definition?  What is a typical resting heart rate?

22. HEART FUNCTION - Cardiac Cycle  Cardiac Cycle: Events that occur between two consecutive heartbeats (systole to systole)  What is Diastole?  What is Systole?

23. HEART FUNCTION - Cardiac Cycle

24. HEART FUNCTION - Heart Rate  Why does heart rate increase during exercise?  How is heart rate increased?

25. HEART FUNCTION – Stroke Volume  What is stroke volume?  What happens to stroke volume during exercise?  How is stroke volume increased?

26. HEART FUNCTION - Cardiac Output (Q)  What is cardiac output?  Cardiac Output = Heart Rate x Stroke Volume  Example: HR of 72 beats/minute x SV of 70 mL/beat  [the beat(s) cancel out] Therefore, Q equals 72 x 70 or 5,040 mL/min or 5.040 L/min

27.  How is cardiac output increased during exercise?  What might cause cardiac output (or blood flow) to decrease during exercise? HEART FUNCTION - Cardiac Output (Q)

28. HEART FUNCTION Heart Rate 50-75 beats per minute Stroke Volume (SV) 60-100 milliliters per beat (ml/beat) Cardiac Output (Q) 4500-5000 milliliters per minute 4.5-5 liters per minute (L/min)

29. a-v O2 Difference  Oxygen Extraction at Rest  Arteries 20 ml or oxygen in every 100 ml of arterial blood  Veins 15 ml/100 ml of blood.  How much oxygen did the muscles use?  This amount is call the a-vO2 difference.

30. THE VASCULAR SYSTEM (Circulation)  Arteries  Arterioles  Capillaries  Venules  Veins

31. THE VASCULAR SYSTEM - Arteries  How do arteries differ from other blood vessels?  Thick and Elastic  Pulse

32. THE VASCULAR SYSTEM - Arterioles  Unique?  Smooth muscle sphincters  Function?  Blood distribution Vasodilation Vasoconstricti on

33. THE VASCULAR SYSTEM - Capillaries  What makes them unique?  Thin  Internal respiration or gas exchange

34. THE VASCULAR SYSTEM - Veins Unique? One-way valves Muscle pump Venous return

35. Muscle Pump

37. BLOOD PRESSURE  Systolic is the pressure in the __________ when the heart is __________.  Diastolic is the pressure in the __________ when the heart is __________.  What is a normal resting blood pressure?  What happens to systolic blood pressure during exercise? Why?  Why is high blood pressure at resting unhealthy?

38. BLOOD PRESSURE

40. THE BLOOD  Transportation: gas, nutrients, and wastes  Regulates temperature  Buffers and balances acid base  What are some of the functions of the blood?

41. THE BLOOD – BLOOD VOLUME

42. THE BLOOD – FORMED ELEMENTS  Red blood cells. What do they do?  White blood cells. What do they do?  Platelets. What do they do?

43. THE BLOOD - Hematocrit  What is Hematrocrit?  Ratio of formed elements (mostly RBC) to the total blood volume  What is a typical value?  45%