Human Biology Sylvia S. Mader Michael Windelspecht Chapter 5 Cardiovascular System: Heart and Blood Vessels Lecture Outline Part 3 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

How is blood pressure categorized? 5.4 Features of the Cardiovascular System How is blood pressure categorized? 2

What is important about blood flow? 5.4 Features of the Cardiovascular System What is important about blood flow? Blood flow is under the highest pressure in the arteries but remember the thick, muscular walls. Blood flow is slower in the capillaries which is important to allow time for exchange between cells. Blood pressure is minimal in the veins and venules but blood flow increases. 3

Blood flow (starting from heart) 5.4 Features of the Cardiovascular System What is important about blood flow? Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. arteries arterioles capillaries venules veins total cross-sectional area of vessels blood pressure velocity Relative magnitude Blood flow (starting from heart) Figure 5.8 Blood velocity and pressure in the blood vessels. 4

5.4 Features of the Cardiovascular System If blood pressure is so low in the veins, why does the blood flow increase? Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. to heart to heart They have help. 1. Skeletal muscle contraction 2. Breathing 3. Valves a. Contracted skeletal muscle pushes blood past open valve. b. Closed valve prevents backward flow of blood. Figure 5.9 The skeletal muscle pump. 5

What are the 2 cardiovascular pathways in the body? 5.5 Two Cardiovascular Pathways What are the 2 cardiovascular pathways in the body? Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CO2 O2 head and arms jugular vein (also subclavian vein from arms) carotid artery (also subclavian artery to arms) _____________ – the right side of the heart that brings blood from the body to the heart and the lungs _____________ – the left side of the heart that brings blood to the entire body to deliver nutrients and rid it of wastes CO2 O2 O2 CO2 lungs pulmonary artery pulmonary vein superior vena cava aorta heart inferior vena cava hepatic vein intestinal artery liver digestive tract hepatic portal vein renal artery renal vein kidneys iliac vein iliac artery Figure 5.10 Overview of the cardiovascular system. CO2 O2 trunk and legs 6

5.5 Two Cardiovascular Pathways Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. common carotid artery external jugular vein internal jugular vein subclavian artery superior vena cava subclavian vein inferior vena cava renal artery renal vein abdominal aorta inferior mesenteric artery mesenteric vein common iliac artery common iliac vein femoral artery femoral vein great sphenoid vein Figure 5.11 The major arteries and veins of the systemic circuit.

The heart’s blood supply: Coronary circulation 5.5 Two Cardiovascular Pathways The heart’s blood supply: Coronary circulation There are small coronary arteries that supply the heart. They are __________ from the systemic and pulmonary pathways of the body. 8

What is the hepatic portal system? 5.5 Two Cardiovascular Pathways What is the hepatic portal system? It is a system that brings amino acid- and glucose-rich blood from the digestive tract to the _____. The liver synthesizes blood proteins and stores the glucose as glycogen. The liver also plays a role in __________ blood from the digestive tract. Finally, the blood will return to the heart via the _____________. 9

5.6 Exchange at the Capillaries Exchange at the capillary beds is primarily a result of osmotic and blood pressure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. from heart to heart Arterial End Blood pressure is higher than osmotic pressure. Net pressure out. Venous End Osmotic pressure is higher than blood pressure. Net pressure in. Tissue Fluid oxygen amino acids carbon dioxide glucose water wastes water salt plasma protein osmotic pressure smooth muscle fiber blood pressure arteriole venule Figure 5.12 The movement of solutes in a capillary bed. 10

Exchange at the capillaries Lymphatic capillary beds lie alongside capillary beds. When lymphatic capillaries take up excess fluid it becomes lymph. Lymph returns to the cardiovascular veins in the chest. Precapillary sphincters can shut down a blood capillary, and blood then flows through the shunt.

Exchange at the capillaries Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. arteriole tissue cells lymphatic capillary blood capillary lymphatic duct venule Figure 5.13 Interaction of lymphatic and capillary beds.

Why should we care about cardiovascular disease? 5.7 Cardiovascular Disorders Why should we care about cardiovascular disease? Cardiovascular disease (CVD) is the most common cause of _______ in the Western world. 13