1. Chapter 15/16-Circulatory System

2. Tainted Love…?

3. Unnumbered figure pg 212
The path of blood

4. Unnumbered figure pg 212
The path of blood

5. FIGURE 12.1
A diagrammatic view of the cardiovascular system (heart and blood vessels). Red indicates blood that is high in oxygen. Blue indicates blood that is low in oxygen.

6. The Blood Vessels Conduct Blood in Continuous Loops
Blood passes through the following loop of vessels moving away from the heart: arteries, arterioles, capillaries, venules, veins and back to the heart

7. FIGURE 12.2 part 2
The structure of blood vessels

8. Blood Vessels
Arteries are thick, muscular vessels that carry blood away from the heart able to withstand high blood pressure
The elasticity of the arteries maintains pressure on the blood between heartbeats to keep it flowing through the vessels
As the heart pumps blood into the arteries they expand such that one is able to feel a pulse

9. Blood Vessels Capillaries have walls that are one cell thick
They form branching networks that allow for the exchange of materials between the blood and tissues

10. FIGURE 12.3a
Capillaries are the sites where materials are exchanged between the blood and the body cells. (a) Substances are exchanged between the blood and tissue fluid across the plasma membrane of the capillary or through slits between capillary cells. (b) At the arterial end of a capillary, blood pressure forces fluid out of the capillary to the fluid surrounding tissue cells. At the venous end, fluid is drawn back into the capillary by osmotic pressure. (c) Capillaries are so narrow that red blood cells must travel through them in single file.

11. FIGURE 12.3b
Capillaries are the sites where materials are exchanged between the blood and the body cells. (a) Substances are exchanged between the blood and tissue fluid across the plasma membrane of the capillary or through slits between capillary cells. (b) At the arterial end of a capillary, blood pressure forces fluid out of the capillary to the fluid surrounding tissue cells. At the venous end, fluid is drawn back into the capillary by osmotic pressure. (c) Capillaries are so narrow that red blood cells must travel through them in single file.

12. Blood Vessels
Most materials simply diffuse across the capillary cell wall into the cells by the force of both blood pressure and osmotic pressure
Water diffuses especially easily and carries many other nutrients with it
Larger molecules are moved by active transport using tiny vesicles

13. Blood Vessels
Veins carry blood back to the heart and also serve as a reservoir for blood volume
Blood is moved against gravity toward the heart by the contracting skeletal muscles and by pressure differences caused by the movement of the thoracic cavity during breathing
Blood is prevented from flowing backwards by valves found in the veins

14. FIGURE 12.6a
(a) A micrograph of a vein showing a valve. (b) Pocketlike valves on the inner surface of veins assist the return of blood to the heart against gravity by preventing backflow.

15. The Heart is a Muscular Pump
The heart is made of cardiac muscle tissue called myocardium
The interior of the heart is lined by endocardium
A fibrous sac, the pericardium, encloses the heart
Epicardium – outer layer, reduces friction
Myocardium – middle layer, mostly cardiac muscle
Endocardium – thin inner lining, within chambers of the heart

16. FIGURE 12.7a
(a) The human heart. (b) The heart is located in the thoracic (chest) cavity. (c) Blood flows through the heart from the atria to the ventricles. (d) This diagram of a human heart shows the four chambers, the major vessels connecting to the heart, and the two pairs of heart valves.

17. FIGURE 12.7b
(a) The human heart. (b) The heart is located in the thoracic (chest) cavity. (c) Blood flows through the heart from the atria to the ventricles. (d) This diagram of a human heart shows the four chambers, the major vessels connecting to the heart, and the two pairs of heart valves.

18. The Heart is a Muscular Pump
The two halves of the heart are separated by a septum
Each half has two chambers, one smaller and thin-walled atrium and one larger, more muscular ventricle

19. Septum – separates the right and left sides of the heart
Heart has 4 chambers:
2 Atria – thin upper chambers that receive blood returning to the heart through veins
2 Ventricles – thick, muscular lower chambers. Receive blood from the atria above them. Force (pump) blood out of the heart through arteries.
Septum – separates the right and left sides of the heart

20. FIGURE 12.7d
(a) The human heart. (b) The heart is located in the thoracic (chest) cavity. (c) Blood flows through the heart from the atria to the ventricles. (d) This diagram of a human heart shows the four chambers, the major vessels connecting to the heart, and the two pairs of heart valves.

21. The Heart is a Muscular Pump
The right side of the heart contains blood rich in carbon dioxide that flows in from the tissues and out to the lungs
The left side of the heart contains blood rich in oxygen returning from the lungs and flowing out to the tissues

22. The Heart is a Muscular Pump
Valves separating the atria from ventricles (AV valves) and the ventricles from the exit vessels (semilunar valves) keep blood from flowing backwards and give rise to the typical lubb-dup sounds of the heartbeat

23. FIGURE 12.8
The valves of the heart keep blood flowing in one direction.

24. FIGURE 12.10a
Coronary circulation. (a) The coronary vessels deliver a rich supply of oxygen and nutrients to the heart muscle cells and remove the metabolic wastes. (b) This cast of the coronary blood vessels reveals the complexity of the coronary circuit.

25. FIGURE 12.10b
Coronary circulation. (a) The coronary vessels deliver a rich supply of oxygen and nutrients to the heart muscle cells and remove the metabolic wastes. (b) This cast of the coronary blood vessels reveals the complexity of the coronary circuit.

26. FIGURE 12.11
The cardiac cycle—the sequence of heart muscle relaxation and contraction. The atria contract together and the ventricles contract together. Red indicates blood high in oxygen. Blue indicates blood low in oxygen.

27. The Heart is a Muscular Pump
The sinoatrial (SA) node generates an electrical signal that sets the tempo and is therefore called the pacemaker
The SA node causes contraction of the atria and sends a signal to the atrioventricular (AV) node which relays information to the atrioventricular bundle and out through the Purkinje fibers causing the ventricles to contract

28. FIGURE part 1
The conduction system of the heart consists of specialized cardiac muscle cells that speed electrical signals through the heart. The sinoatrial (SA) node serves as the heart's internal pacemaker that determines the heart rate. Electrical signals from the SA node spread through the walls of the atria, causing them to contract. The signals then stimulate the atrioventricular (AV) node, which in turn sends the signals along the atrioventricular AV bundle to its forks and finally to the many Purkinje fibers that penetrate the ventricular walls. The Purkinje fibers distribute the signals to the walls of the ventricles, causing them to contract. Electrical activity is indicated by the color blue in the bottom row of drawings.

29. FIGURE part 2
The conduction system of the heart consists of specialized cardiac muscle cells that speed electrical signals through the heart. The sinoatrial (SA) node serves as the heart's internal pacemaker that determines the heart rate. Electrical signals from the SA node spread through the walls of the atria, causing them to contract. The signals then stimulate the atrioventricular (AV) node, which in turn sends the signals along the atrioventricular AV bundle to its forks and finally to the many Purkinje fibers that penetrate the ventricular walls. The Purkinje fibers distribute the signals to the walls of the ventricles, causing them to contract. Electrical activity is indicated by the color blue in the bottom row of drawings.

30. The Heart is a Muscular Pump
A combination of nervous and endocrine signals control the strength and rate of contraction of the heart
An electrocardiogram (ECG/EKG), a powerful diagnostic tool, is a recording of the electrical events associated with the heartbeat

31. FIGURE 12.13b
(a) A person having an electrocardiogram (ECG) recorded. (b) The electrical activity that accompanies each heartbeat can be visualized in an ECG tracing. The P wave is generated as the electrical signals from the SA node spread across the atria and cause them to contract. The QRS wave represents the spread of the signal through the ventricles and ventricular contraction. The T wave occurs as the ventricles recover and return to the electrical state that preceded contraction.

32. The Heart is a Muscular Pump
Blood pressure is its highest (systolic) when the ventricles contract sending blood into the arteries and at its lowest (diastolic) when the heart relaxes between beats

33. Cardiovascular Disease Is a Major Killer in the United States
A sphygmomanometer measures blood pressure and can provide early identification of hypertension, or high blood pressure, the silent killer
Atheroscloerosis, a narrowing of the arteries due to fatty deposits and thickening of the wall, can lead to heart attack or stroke
When this occurs in the arteries of the heart muscle, it is called coronary artery disease

34. FIGURE part 1
Blood pressure is measured with a sphygmomanometer, which consists of an inflatable cuff and a means of measuring the pressure within the cuff. The cuff is placed around the upper arm and inflated so that it compresses the brachial artery. The pressure in the cuff is slowly released, and as it descends it reaches a point where blood is able to spurt through the constricted artery only at the moments of highest blood pressure. This pressure, at which "tapping" sounds are first heard, is the systolic pressure, the blood pressure when the heart is contracting. As the pressure in the cuff continues to drop, a point is reached where the sounds disappear. The blood is now flowing continuously through the brachial artery. The pressure in the cuff when the sounds first disappear is the diastolic pressure, the blood pressure when the heart is relaxing.

35. FIGURE part 2
Blood pressure is measured with a sphygmomanometer, which consists of an inflatable cuff and a means of measuring the pressure within the cuff. The cuff is placed around the upper arm and inflated so that it compresses the brachial artery. The pressure in the cuff is slowly released, and as it descends it reaches a point where blood is able to spurt through the constricted artery only at the moments of highest blood pressure. This pressure, at which "tapping" sounds are first heard, is the systolic pressure, the blood pressure when the heart is contracting. As the pressure in the cuff continues to drop, a point is reached where the sounds disappear. The blood is now flowing continuously through the brachial artery. The pressure in the cuff when the sounds first disappear is the diastolic pressure, the blood pressure when the heart is relaxing.

36. FIGURE 12.15a
Atherosclerosis, a low-level inflammatory response in the wall of an artery, is associated with the formation of fat-filled plaques. Plaque can obstruct blood flow through the artery, thus depriving the cells that would be fed life-sustaining blood by the artery. Plaque can also rupture, causing a blood clot to form. The clot may then completely clog the vessel and cause the death of tissue downstream.

37. Cardiovascular Disease
Angiography can show coronary artery blockage, which can then be treated with medicines or surgical operations such as angioplasty or coronary bypass surgery

38. FIGURE 12.16
Balloon angioplasty opens a partially blocked artery.

39. Cardiovascular Disease
Heart muscle dies during a heart attack and is gradually replaced by scar tissue
During heart failure the heart becomes an inefficient pump leading to shortness of breath, fatigue, and fluid accumulation

40. The Lymphatic System
The lymphatic system functions to return interstitial fluid to the blood stream, to transport products of fat digestion and to defend the body against disease-causing organisms and abnormal cells

41. The Lymphatic System
Lymph nodes filter lymph and contain macrophages and lymphocytes that actively defend against disease-causing organisms
Lymphoid organs include the tonsils, thymus gland, spleen, and Peyer’s patches

42. FIGURE 12.21
The lymphatic system is a system of lymphatic vessels containing a clear fluid, called lymph, and various lymphatic tissues and organs located throughout the body.

43. FIGURE 12.20
The lymphatic capillaries are microscopic, blind-ended tubules through which surplus tissue fluid enters the lymphatic system to be returned to the bloodstream.