The liquid part of blood is called 1. 2. 3. 4. 5. A) water. B) plasma. C) serum. D) extrastitial fluid. E) anionic fluid. Circulatory & respiratory systems Chs 12 & 14 Lecture outline • Review of blood- functions & parts • Ch. 12: Circulation- The path of blood – Arteries, veins & capillaries – The circulatory pathway • The heart- structure & function – Blood pressure • Cardiovascular disease • The lymphatic system • The respiratory system– Structure & function – Respiratory disorders Announcements • Blood lab- Due today! • Ch 12 online- Due Wednesday! Blood review • Parts of blood • Function of blood Blood is a mixture of cells and plasma Human Blood after centrifugation • ~55% Plasma • ~45% Red blood cells • <1% White blood cells and platelets (“buffy coat”) Blood plasma • Water • Nutrients • Solutes- Na+, Cl-, wastes, CO2, etc. • Functions: – – – – – Carry nutrients to cells Dissolve wastes in cells Osmotic equilibrium Factors to fight infection Clotting factors also All blood cells are part of the hematopoetic stem cell lineage Red blood cells carry oxygen and CO2 • Lose nucleus in development • Short-lived, no repair • Packed solid with hemoglobin • Membranes designed to maximize surface area • Facilitate gas transfer Hemoglobin is the oxygen-binding protein in red blood cells • The oxygen-carrying protein • Heterotetrameric protein • 2 alpha subunits, 2 beta • Each subunit holds a Heme group • Each heme holds an Fe++ ion • Each Fe++ can bind an O2 Hemoglobin binding curve • In areas of High O2 (e.g., lungs)- binds O2 very well (picks up O2) • In areas of Low O2 (e.g., muscles) binds O2 poorly (drops off O2) • Myoglobin binds O2 in muscle & organ tissues Sickle Cell Anemia is a genetic disorder caused by a mutation in hemoglobin • ) Platelets assist with blood clotting • Recruit plasma protein fibrinogen to a cut • They release clotting factors • Clotting factors convert fibrinogen to fibrin • Fibrin net prevents blood loss White blood cells fight infection • B cells make antibodies • T cells kill cancerous cells and invaders • Macrophages swallow bacteria • Granulocytes (eosinophils, neutrophils, basophils) secrete histamines & other toxins against allergens, worms, and bacteria The Immune system is the body’s defense system • Against: – – – – – – – Bacteria Viruses Protists Other living invaders Toxins Foreign debris Cancerous cells • The immune system is complex • Defends against threats known and unknown The circulatory system The Cardiovascular System • The cardiovascular system is composed of – Blood – Blood vessels – Heart The Cardiovascular System Veins • Carry blood back to the heart Superior vena cava • Carries blood from the upper body back to the heart Jugular veins • Carry blood from head to the heart Pulmonary veins • Carry oxygenated blood from the lungs to the heart Renal vein • Carries blood from the kidney to the heart Inferior vena cava • Carries blood from the lower body back to the heart Radial vein • Carries blood from the hand back to the heart Iliac vein • Carries blood from the pelvic organs and abdominal wall back to the heart Femoral vein • Carries blood from the thigh and inner knee back to the heart Figure 12.1 (1 of 2) The Blood Vessels Conduct Blood in 2 Continuous Loops • Blood passes through the following loop of vessels moving away from the heart – Arteries – Arterioles – Capillaries – Venules – Veins • Blood returns to the heart from the veins Veins and arteries travel in parallel Arteries • Carry blood away from heart Carotid arteries • Deliver blood to the head and the brain Coronary arteries • Deliver blood to the heart muscle cells Aorta • Delivers blood to the body tissues Pulmonary arteries • Deliver oxygen-poor blood to the lungs Renal artery • Delivers blood to the kidney Iliac artery • Delivers blood to pelvic organs and abdominal wall Radial artery • Delivers blood to the hand Femoral artery • Delivers blood to thigh and inner knee The Blood Vessels Conduct Blood in Continuous Loops Figure 12.2 Capillaries facilitate gas, nutrient & waste transfer Figure 12.3b Capillaries are made of epithelial tissue Figure 12.3c The Blood Vessels Conduct Blood in Continuous Loops To tissue cells Slit between cells Capillary cell Nucleus Red blood cell (a) Substances are exchanged between the blood and tissue fluid across the plasma membrane of the capillary or through slits between capillary cells. Figure 12.3a The Blood Vessels Conduct Blood in Continuous Loops Figure 12.3 Blood Vessels • The hollow interior of all blood vessels is called the lumen Blood Vessels • Arteries – Thick, muscular vessels that carry blood away from the heart – “A= away” – Are able to withstand high blood pressure – Thick walls make arteries pliable and durable Blood Vessels • The elasticity of the arteries maintains pressure on the blood between heartbeats to keep it flowing through the vessels Blood Vessels • As the heart pumps blood into the arteries, they expand such that one is able to feel a pulse • The pulse rate is the same as the heart rate Blood Vessels • Vasoconstriction – When muscle contracts and the diameter of the lumen narrows, reducing blood flow • Vasodilation – When muscle relaxes and the diameter of the lumen increases, increasing blood flow Blood Vessels • Arterioles are the prime controllers of blood pressure • Arterioles serve as gatekeepers to the capillary networks keeping them open or closed Blood Vessels Figure 12.4b Blood Vessels • An aneurysm occurs when the wall of an artery is weakened and swells • The primary risk is that it will burst, causing blood loss • If it does not burst it can form life-threatening clots Blood Vessels • Capillaries have walls that are one cell thick and connect arterioles and venules Blood Vessels Figure 12.4a Arterioles have sphincter muscles Figure 12.4b (1 of 2) Blood Vessels Blood Vessels • Capillaries form branching networks that allow for the exchange of materials between the blood and tissues • Blood flows more slowly due to the large surface area – Provides more time for the exchange of materials Blood Vessels • Capillaries merge to form the smallest kind of vein, a venule – Venules join to form larger veins • Veins – Carry blood back to the heart – Serve as reservoirs for blood volume Blood Vessels • Veins – Blood is moved against gravity toward the heart by • Contracting skeletal muscles • Pressure differences caused by the movement of the thoracic cavity during breathing • Valves – Prevent blood flowing backwards Vein walls are thinner and weaker than arteries Figure 12.6a Veins have valves for one-way bloodflow Valve open Valve closed Muscle contraction squeezes the vein, pushing blood through the open valve toward the heart. Skeletal muscles relax, and blood fills the valves and closes them. (b) Valve closed Relaxed calf muscles Contracted calf muscles Figure 12.6b • Which of the following are found in veins that help direct blood flow in one direction only toward the heart? • A) Valves • B) Lymph nodes • C) Myocardium • D) Pericardium The pathway of blood Area vs. blood velocity in the circulatory system Figure 12.5 Blood Vessels • Most materials simply diffuse across the capillary cell wall into the cells by the force of both blood pressure and osmotic pressure The heart pumps the blood through two circulatory pathways Oxygen-rich blood (to body) Oxygen-poor blood (c) (from body cells) Oxygen-poor blood (to lungs) Oxygen-rich blood (from lungs) Figure 12.7c The Heart The Heart is a Muscular Pump • The heart is made of cardiac muscle tissue called myocardium The Heart is a Muscular Pump Figure 12.7a The Heart is a Muscular Pump Figure 12.7b The Heart is a Muscular Pump • The interior of the heart is lined by endocardium • A fibrous sac, the pericardium, encloses the heart and holds the heart in the center of the thoracic cavity 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 – One larger, more muscular ventricle The Heart is a Muscular Pump Superior vena cava Right pulmonary arteries Aorta Left pulmonary arteries Pulmonary trunk Pulmonary semilunar valve Left pulmonary veins Right atrium Right pulmonary veins Right atrioventricular valve (tricuspid valve) Chordae tendineae Right ventricle Inferior vena cava (d) Left atrium Aortic semilunar valve (hidden from view) Left atrioventricular valve (mitral valve) Left ventricle Myocardium Endocardium Pericardium Septum Figure 12.7d The Heart is a Muscular Pump • The right side of the heart – Contains blood rich in carbon dioxide • Returns from the tissues • Flows out to the lungs • The left side of the heart – Contains blood rich in oxygen • Returns from the lungs • Flows out to the tissues The Heart has valves for one-way bloodflow • Valves – Atrioventricular (AV) valves • Separate the atria from ventricles – Semilunar valves • Separate the ventricles from the exit vessels • Keep blood from flowing backwards – Give rise to the typical “lub-dup” sounds of the heartbeat The Heart is a Muscular Pump • The AV valve on the right – Called the tricuspid valve – Has three flaps • The AV valve on the left – Called the bicuspid or mitral valve – Has two flaps The Heart is a Muscular Pump Figure 12.8 The Heart is a Muscular Pump • Pulmonary Circuit – The right side of the heart pumps blood to and from the lungs • Systemic Circuit – The left side of the heart pumps blood to and from the tissues The Heart is a Muscular Pump Systemic circuit • Gas exchange in capillary beds throughout body tissues Right side Left side Pulmonary circuit • Gas exchange in lungs Superior vena cava Aorta Pulmonary artery Pulmonary artery Pulmonary veins Oxygen-rich blood (to body) Inferior vena cava Oxygen-poor blood (from body cells) Oxygen-rich blood (from lungs) Pulmonary veins Oxygenpoor blood (to lungs) Aorta Figure 12.9 The Heart is a Muscular Pump • The heart muscle is nourished by coronary circulation The Heart is a Muscular Pump Aorta Pulmonary veins Superior vena cava Pulmonary trunk Right coronary vein Right coronary artery Left coronary artery Left coronary vein Inferior vena cava (a) Figure 12.10a The Heart is a Muscular Pump Figure 12.10b The Heart is a Muscular Pump • The cardiac cycle – Contraction of the atria – Followed by contraction of the ventricles – Followed by a rest when neither chamber is contracting • Contraction is called systole • Relaxation is called diastole The Heart is a Muscular Pump Figure 12.11 The Heart is a Muscular Pump • The sinoatrial (SA) node – Generates an electrical signal that sets the tempo – Called the pacemaker The Heart is a Muscular Pump • 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 The Heart is a Muscular Pump Figure 12.12 (1 of 5) The Heart is a Muscular Pump Figure 12.12 (2 of 5) The Heart is a Muscular Pump Figure 12.12 (3 of 5) The Heart is a Muscular Pump Figure 12.12 (4 of 5) The Heart is a Muscular Pump Figure 12.12 (5 of 5) The Heart is a Muscular Pump • A combination of nervous and endocrine signals control the strength and rate of contraction of the heart The Heart is a Muscular Pump • An electrocardiogram (ECG/EKG) – Recording of the electrical events associated with the heartbeat – A powerful diagnostic tool • Abnormal patterns can indicate heart problems The Heart is a Muscular Pump Figure 12.13a The Heart is a Muscular Pump • A typical ECG/EKG consists of three distinguishable deflection waves – P wave – QRS wave – T wave The Heart is a Muscular Pump Figure 12.13b • Blood vessels that serve as gateways to capillary beds are: • A) venules. • B) arteries. • C) arterioles. • D) veins. • Which of these is the portion of the heartbeat that involves contraction of the heart? • A) Cardiac cycle • B) Pacemaker • C) Diastole • D) Systole Cardiovascular disease The Heart is a Muscular Pump • Blood pressure – Highest (systolic) when the ventricles contract, sending blood into the arteries – Lowest (diastolic) when the heart relaxes between beats Cardiovascular Disease Is a Major Killer in the United States • Sphygmomanometer – Measures blood pressure – Can provide early identification of hypertension, or high blood pressure, the silent killer Cardiovascular Disease Is a Major Killer in the United States Figure 12.14 (1 of 2) Cardiovascular Disease Is a Major Killer in the United States Figure 12.14 (2 of 2) Cardiovascular Disease • 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 Cardiovascular Disease Figure 12.16a Cardiovascular Disease Figure 12.16b Cardiovascular Disease Figure 12.16c 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 Cardiovascular Disease Figure 12.17 Cardiovascular Disease Figure 12.18 Cardiovascular Disease • Heart muscle dies because of an insufficient blood supply during a heart attack (myocardial infarction) and is gradually replaced by scar tissue • Scar tissue cannot contract, so part of the heart permanently loses its pumping ability PLAY | Lawsuit over Vioxx Cardiovascular Disease Figure 12.19 Cardiovascular Disease • Heart failure – Condition in which the heart becomes an inefficient pump – Leads to shortness of breath, fatigue, and fluid accumulation The Lymphatic System • Lymphatic system functions – Return interstitial fluid to the blood stream – Transport products of fat digestion – Defend the body against disease-causing organisms and abnormal cells The Lymphatic System Tonsils • Protect the throat against bacteria and foreign agents Right lymphatic duct • Returns the lymph from the upper part of body to the blood Thoracic duct • Returns lymph from most of the body to the blood Lymph vessels • Return excess interstitial fluid to the blood • Some transport products of fat digestion to the blood (a) The lymphatic system returns the fluid to the bloodstream that previously left the capillaries to bathe the cells, protects against disease-causing organisms, and transports products of fat digestion from the small intestine to the bloodstream. Thymus • Site where T lymphocytes mature, enabling them to fight specific disease-causing organisms Spleen • Site of lymphocyte production • Removes old red blood cells, foreign debris, and microorganisms from the blood Lymph nodes • Filter lymph before returning it to the blood • Contain lymphocytes and macrophages that defend against disease-causing organisms Figure 12.22a The Lymphatic System Figure 12.22b The Lymphatic System • Elephantiasis – A condition in which parasites block the passage of lymphatic fluid returning to blood – Results in massive swelling, darkening, and thickening of the skin in the affected area The Lymphatic System Figure 12.20 The Lymphatic System • Lymph – Interstitial fluid that builds up around the cells – Enters the lymph capillaries, then passes through a series of vessels and is returned to the circulatory system The Lymphatic System Figure 12.21 The Lymphatic System Tissue cells Anchoring filaments Interstitial fluid enters Endothelium Flaplike minivalve Figure 12.21 (1 of 2) The Lymphatic System Arteriole Blood Venule capillaries Lymph capillaries Tissue cells Figure 12.21 (2 of 2) The Lymphatic System • Lymph nodes – Bean–shaped structures – Filter lymph – Contain macrophages and lymphocytes that actively defend against disease-causing organisms The Lymphatic System Figure 12.22b The Lymphatic System • Lymphoid organs include – Tonsils – Thymus gland – Spleen – Peyer’s patches The Lymphatic System Tonsils • Protect the throat against bacteria and foreign agents Right lymphatic duct • Returns the lymph from the upper part of body to the blood Thoracic duct • Returns lymph from most of the body to the blood Lymph vessels • Return excess interstitial fluid to the blood • Some transport products of fat digestion to the blood (a) The lymphatic system returns the fluid to the bloodstream that previously left the capillaries to bathe the cells, protects against disease-causing organisms, and transports products of fat digestion from the small intestine to the bloodstream. Thymus • Site where T lymphocytes mature, enabling them to fight specific disease-causing organisms Spleen • Site of lymphocyte production • Removes old red blood cells, foreign debris, and microorganisms from the blood Lymph nodes • Filter lymph before returning it to the blood • Contain lymphocytes and macrophages that defend against disease-causing organisms Figure 12.22a