Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? -Transport nutrients & O 2 to all cells -Transport metabolic waste to kidneys & CO 2 to lungs 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? -Gastrovascular cavity -digestion & distribution of nutrients -2 cell layered thick organisms – Cnidarians

Figure 42.2 Internal transport in the cnidarian Aurelia Circular canal Radial canal 5 cm Mouth

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? -Transport nutrients & O 2 to all cells -Transport metabolic waste to kidneys & CO 2 to lungs 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? -Gastrovascular cavity -digestion & distribution of nutrients -2 cell layered thick organisms – Cnidarians -Animals with more than 2 cell layers need more

Heart Hemolymph in sinuses surrounding ograns Interstitial fluid Heart Small branch vessels in each organ Anterior vessel Lateral vessels Ostia Tubular heart Dorsal vessel (main heart) Ventral vessels Auxiliary hearts (a) An open circulatory system(b) A closed circulatory system Figure 42.3 Open and closed circulatory systems -Heart pump hemolymph into large cavity -VERY inefficient due to mixing of good & bad substances -Heart pump blood through vessels in a complete circuit -More efficient & consistent

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? -Transport nutrients & O 2 to all cells -Transport metabolic waste to kidneys & CO 2 to lungs 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? -Gastrovascular cavity -digestion & distribution of nutrients -2 cell layered thick organisms – Cnidarians -Animals with more than 2 cell layers need more 3. Let’s compare some vertebrate hearts

Figure 42.4 Vertebrate Circulatory Systems FISHES AMPHIBIANSREPTILES (EXCEPT BIRDS)MAMMALS AND BIRDS Systemic capillaries Lung capillaries Lung and skin capillariesGill capillaries Right Left RightLeft Right Left Systemic circuit Pulmocutaneous circuit Pulmonary circuit Systemic circulation Vein Atrium (A) Heart: ventricle (V) Artery Gill circulation A V V VVV A A A AA Left Systemic aorta Right systemic aorta - 1atrium & 1 ventricle - single circuit - blood flows from gills directly to rest of the body - BP is LOW after gill capillaries - Swimming helps blood complete the circuit FISH

Figure 42.4 Vertebrate Circulatory Systems FISHES AMPHIBIANSREPTILES (EXCEPT BIRDS)MAMMALS AND BIRDS Systemic capillaries Lung capillaries Lung and skin capillariesGill capillaries Right Left RightLeft Right Left Systemic circuit Pulmocutaneous circuit Pulmonary circuit Systemic circulation Vein Atrium (A) Heart: ventricle (V) Artery Gill circulation A V V VVV A A A AA Left Systemic aorta Right systemic aorta - 2 atria & 1 ventricle - Double circulation - blood flows from ventricle to pulmocutaneous circuit, back to the heart & then from the same ventricle to the systemic capillaries - Mixing of blood in ventricle is INEFFICIENT AMPHIBIANS

Figure 42.4 Vertebrate Circulatory Systems FISHES AMPHIBIANSREPTILES (EXCEPT BIRDS)MAMMALS AND BIRDS Systemic capillaries Lung capillaries Lung and skin capillariesGill capillaries Right Left RightLeft Right Left Systemic circuit Pulmocutaneous circuit Pulmonary circuit Systemic circulation Vein Atrium (A) Heart: ventricle (V) Artery Gill circulation A V V VVV A A A AA Left Systemic aorta Right systemic aorta - 2 atria & 1 ventricle - pulmonary circuit since skin is dry - 90% ridge between right & left ventricles - ridge is complete in crocodilians - Mixing of blood in ventricle is less REPTILES

Figure 42.4 Vertebrate Circulatory Systems FISHES AMPHIBIANSREPTILES (EXCEPT BIRDS)MAMMALS AND BIRDS Systemic capillaries Lung capillaries Lung and skin capillariesGill capillaries Right Left RightLeft Right Left Systemic circuit Pulmocutaneous circuit Pulmonary circuit Systemic circulation Vein Atrium (A) Heart: ventricle (V) Artery Gill circulation A V V VVV A A A AA Left Systemic aorta Right systemic aorta - 2 atria & 2 ventricles - no mixing of O 2 -rich & O 2 poor blood - 2 complete circuits – pulmonary & systemic MAMMALS

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? -Transport nutrients & O 2 to all cells -Transport metabolic waste to kidneys & CO 2 to lungs 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? -Gastrovascular cavity -digestion & distribution of nutrients -2 cell layered thick organisms – Cnidarians -Animals with more than 2 cell layers need more 3.Let’s compare some vertebrate hearts 4.What is the route of blood flow through our circulatory system?

Right atrium Right ventricle Posterior vena cava Capillaries of abdominal organs and hind limbs Aorta Left ventricle Left atrium Pulmonary vein Pulmonary artery Capillaries of left lung Capillaries of head and forelimbs Anterior vena cava Pulmonary artery Capillaries of right lung Pulmonary vein Aorta Figure 42.5 The mammalian cardiovascular system: an overview

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? 3.Let’s compare some vertebrate hearts 4.What is the route of blood flow through our CV system? 1.Right ventricle 2.Pulmonary artery 3.Pulmonary capillaries 4.Left atrium 5.Left ventricle 6.Aorta 7.Capillaries above heart – head & arms 8.Capillaries below heart – abdominal organs & legs 9.Anterior vena cava – from above heart 10. Posterior vena cava – from below heart 11. Right atrium 5. How does structure fit function of the heart?

Figure 42.6 The mammalian heart: a closer look Aorta Pulmonary artery Left atrium Pulmonary veins Semilunar valve Atrioventricular valve Left ventricle Right ventricle Anterior vena cava Pulmonary artery Semilunar valve Atrioventricular valve Posterior vena cava Pulmonary veins Right atrium

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? 3.Let’s compare some vertebrate hearts 4.What is the route of blood flow through our CV system? 5.How does structure fit function of the heart? -Atria have thin walls – only pump to ventricles below -Ventricles have THICK walls – left is thickest -Valves prevent back flow -Atrioventricular valves – between atria & ventricles -Semilunar valves - between ventricles & exit vessels 6. How is the heart beat controlled?

Figure 42.8 The control of heart rhythm SA node (pacemaker) AV node Bundle branches Heart apex Purkinje fibers 1 2 Signals are delayed at AV node. Pacemaker generates wave of signals to contract. 3 Signals pass to heart apex. 4 Signals spread throughout ventricles. ECG

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? 3.Let’s compare some vertebrate hearts 4.What is the route of blood flow through our CV system? 5.How does structure fit function of the heart? -Atria have thin walls – only pump to ventricles below -Ventricles have THICK walls – left is thickest -Valves prevent back flow -Atrioventricular valves – between atria & ventricles -Semilunar valves - between ventricles & exit vessels 6.How is the heart beat controlled? 7.How does blood flow through our vessels?

Artery Vein 100 µm ArteryVein Arteriole Venule Connective tissue Smooth muscle Endothelium Connective tissue Smooth muscle Endothelium Valve Endothelium Basement membrane Capillary Figure 42.9 The structure of blood vessels

Figure Blood flow in veins Direction of blood flow in vein (toward heart) Valve (open) Skeletal muscle Valve (closed)

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? 3.Let’s compare some vertebrate hearts 4.What is the route of blood flow through our CV system? 5.How does structure fit function of the heart? 6.How is the heart beat controlled? 7.How does blood flow through our vessels? 8.What is the relationship between vessel size, BP & velocity?

Figure The interrelationship of blood flow velocity, cross- sectional area of blood vessels, and blood pressure 5,000 4,000 3,000 2,000 1, Aorta Arteries Arterioles Capillaries Venules Veins Venae cavae Pressure (mm Hg) Velocity (cm/sec) Area (cm 2 ) Systolic pressure Diastolic pressure - Capillaries increase surface area - Cells flow through single file - Slow flow means better ability for exchange

Figure Fluid exchange between capillaries and the interstitial fluid At the arterial end of a capillary, blood pressure is greater than osmotic pressure, and fluid flows out of the capillary into the interstitial fluid. Capillary Red blood cell 15  m Tissue cell INTERSTITIAL FLUID Capillary Net fluid movement out Net fluid movement in Direction of blood flow Blood pressure Osmotic pressure Inward flow Outward flow Pressure Arterial end of capillary Venule end At the venule end of a capillary, blood pressure is less than osmotic pressure, and fluid flows from the interstitial fluid into the capillary.

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? 3.Let’s compare some vertebrate hearts 4.What is the route of blood flow through our CV system? 5.How does structure fit function of the heart? 6.How is the heart beat controlled? 7.How does blood flow through our vessels? 8.What is the relationship between vessel size, BP & velocity? 9.What is blood made of?

Plasma 55% Constituent Major functions Water Solvent for carrying other substances Sodium Potassium Calcium Magnesium Chloride Bicarbonate Osmotic balance pH buffering, and regulation of membrane permeability Albumin Fibringen Immunoglobulins (antibodies) Plasma proteins Icons (blood electrolytes Osmotic balance, pH buffering Clotting Defense Substances transported by blood Nutrients (such as glucose, fatty acids, vitamins) Waste products of metabolism Respiratory gases (O 2 and CO 2 ) Hormones Cellular elements 45% Cell type Number per  L (mm 3 ) of blood Separated blood elements Functions Erythrocytes (red blood cells) 5–6 million Transport oxygen and help transport carbon dioxide Leukocytes (white blood cells) 5,000–10,000 Defense and immunity Eosinophil Basophil Platelets NeutrophilMonocyte Lymphocyte 250,000  400,000 Blood clotting Figure The composition of mammalian blood

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? 3.Let’s compare some vertebrate hearts 4.What is the route of blood flow through our CV system? 5.How does structure fit function of the heart? -Atria have thin walls – only pump to ventricles below -Ventricles have THICK walls – left is thickest -Valves prevent back flow -Atrioventricular valves – between atria & ventricles -Semilunar valves - between ventricles & exit vessels 6.How is the heart beat controlled? 7.How does blood flow through our vessels? 8.What is the relationship between vessel size, BP & velocity? 9.What is blood made of? 10. Where do blood cells originate?

Figure Differentiation of blood cells B cells T cells Lymphoid stem cells Pluripotent stem cells (in bone marrow) Myeloid stem cells Erythrocytes Platelets Monocytes Neutrophils Eosinophils Basophils Lymphocytes Ch 43 Erythropoeitin (EPO) – kidney hormone released in response to low O2 to stimulate production of erythrocytes

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? 3.Let’s compare some vertebrate hearts 4.What is the route of blood flow through our CV system? 5.How does structure fit function of the heart? 6.How is the heart beat controlled? 7.How does blood flow through our vessels? 8.What is the relationship between vessel size, BP & velocity? 9.What is blood made of? 10. Where do blood cells originate? 11. How does blood clot?

Platelet plug Collagen fibers Platelet releases chemicals that make nearby platelets sticky Clotting factors from: Platelets Damaged cells Plasma (factors include calcium, vitamin K) Prothrombin Thrombin FibrinogenFibrin 5 µm Fibrin clot Red blood cell The clotting process begins when the endothelium of a vessel is damaged, exposing connective tissue in the vessel wall to blood. Platelets adhere to collagen fibers in the connective tissue and release a substance that makes nearby platelets sticky. 1 The platelets form a plug that provides emergency protection against blood loss. 2 This seal is reinforced by a clot of fibrin when vessel damage is severe. Fibrin is formed via a multistep process: Clotting factors released from the clumped platelets or damaged cells mix with clotting factors in the plasma, forming an activation cascade that converts a plasma protein called prothrombin to its active form, thrombin. Thrombin itself is an enzyme that catalyzes the final step of the clotting process, the conversion of fibrinogen to fibrin. The threads of fibrin become interwoven into a patch (see colorized SEM). 3 Figure Blood clotting

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? 3.Let’s compare some vertebrate hearts 4.What is the route of blood flow through our CV system? 5.How does structure fit function of the heart? 6.How is the heart beat controlled? 7.How does blood flow through our vessels? 8.What is the relationship between vessel size, BP & velocity? 9.What is blood made of? 10. Where do blood cells originate? 11. How does blood clot? 12. What are some CV diseases? ->50% of deaths due to CV disease -LDLs – low-density lipoproteins - bad cholesterol -Associated with arterial plaques -HDLs – high-density lipoproteins – good cholesterol -Reduce deposition of cholesterol

Figure Atherosclerosis (a) Normal artery (b) Partly clogged artery 50 µm250 µm Smooth muscle Connective tissue Endothelium Plaque - Atherosclerosis – cholesterol plaques in arteries slows blood flow - Arteriosclerosis – hardening of the arteries due to Ca +2 added to plaques

Chapter 42: Circulation and Gas Exchange 1.What is the function of the circulatory system? 2.What is the difference between a gastrovascular cavity and an open & closed circulatory system? 3.Let’s compare some vertebrate hearts 4.What is the route of blood flow through our CV system? 5.How does structure fit function of the heart? 6.How is the heart beat controlled? 7.How does blood flow through our vessels? 8.What is the relationship between vessel size, BP & velocity? 9.What is blood made of? 10. Where do blood cells originate? 11. How does blood clot? 12. What are some CV diseases? -LDLs – low-density lipoproteins - bad cholesterol -HDLs – high-density lipoproteins – good cholesterol -Hypertension – high BP -Heart attack – death of heart muscle due to blocked coronary arteries -Stroke – death of nervous tissue in brain due to blocked brain arteries