Unit 13 circulatory system
- 2. Circulatory System Components I. Heart II. Blood Vessels Veins, Capillaries, and Arteries Components of Blood Lymphatic System Blood Type Circulatory Problems (**Closed System**)
- 3. A. Circulation Muscle contractions cause blood to pump Pulmonary Circulation -Blood pumped from right side of heart to lungs Systemic Circulation - Blood pumped to the rest of the body I. Heart Capillaries of head and arms Capillaries of abdominal organs and legs Inferior vena cava Pulmonary vein Capillaries of right lung Superior vena cava Aorta Pulmonary artery Capillaries of left lung
- 4. The Heart Heart B. Structure Composed mainly of muscle Pericardium - Protective layer surrounding the heart Myocardium – muscle found in the heart walls, responsible for pumping blood Septum – Divides heart into 2 halves, Restricts mixing of blood Each side has two chambers Atrium (Upper Chamber) – Receives blood Ventricle (Lower Chamber) – pumps blood out of the heart Contains Valves that keep blood flowing in one direction Pumps enough blood to fill an Olympic-sized swimming pool a year Click To Enlarge
- 5. Superior Vena Cava Large vein that brings oxygen-poor blood from the upper part of the body to the right atrium Aorta Brings oxygen-rich blood from the left ventricle to the rest of the body Pulmonary Arteries Bring oxygen-poor blood to the lungs Pulmonary Veins Bring oxygen-rich blood from each of the lungs to the left atrium Pulmonary Valve Prevents blood from flowing back into the right ventricle after it has entered the pulmonary artery Right Atrium Tricuspid Valve Prevents blood from flowing back into the right atrium after it has entered the right ventricle Inferior Vena Cava Vein that brings oxygen-poor blood from the lower part of the body to the right atrium Right Ventricle Septum Left Ventricle Mitral Valve Prevents blood from flowing back into the left atrium after it has entered the left ventricle Aortic Valve Prevents blood from flowing back into the left ventricle after it has entered the aorta Left Atrium Question: What is the advantage of a 4-chambered heart?
- 6. I. Heart Coronary Artery: Supplies the heart muscle itself with blood
- 7. C. Heartbeat Sinoatrial Node (Pacemaker) Located in the right atrium Cardiac muscles contract in waves causing blood to leave the atria into ventricle Stimulated by nerve impulse from the medulla Atrioventricular Node Location – base of right atrium & beginning of right ventricle Transfers impulse from atria muscles and transfers them to ventricle muscles Ventricles contract causing blood to leave heart
- 8. I. Heart C. Heartbeat Each heartbeat is called a cardiac cycle: two atria contract then two ventricles contract (systole), and the entire heart relaxes (diastole) A normal heart beats 70 times per minute. Makes a “lub-dub” sound as the valves of the heart are opening and closing.
- 9. I. Heart 1. Electrocardiogram (ECG or EKG) A test that records the electrical activity of the heart. The P wave represents contraction (systole) of the atria. The QRS wave occurs just before ventricular relaxation (diastole). Examination of ECG can determine abnormalities such as fibrillation. Question: What are some problems associated with the Sinoatrial Node? How can it be fixed?
- 11. I. Heart 2. Pacemaker Abnormal heartbeats can be controlled by an artificial pacemaker that is run on batteries
- 13. II. Blood Vessels A. Veins 1. Vessel that returns blood to the heart 2. Contains valves – unidirectional flow
- 14. II. Blood Vessels B. Capillaries 1. The smallest blood vessels (one cell thick) 2. Responsible for delivering nutrients & Oxygen to tissue and absorbing wastes and Carbon Dioxide
- 15. II. Blood Vessels C. Arteries 1. Large vessels that carry blood away from the heart to tissues throughout the body 2. All arteries except the pulmonary, carry Oxygen rich blood 3. Thick walls that help cope with high pressure from heart contractions (Elasticity)
- 16. II. Blood Vessels C. Arteries Cont. 4. Blood Pressure Definition: Force that is exerted by the blood upon the walls of the blood vessels. a. Regulated in 2 ways: Sensory –neurons attached to blood vessels detect blood pressure If too low – neurons (nerve cells) stimulate nervous system to increase heart rate If too high – stimulate nervous system to decrease (slow down) heart rate Kidneys When blood pressure is high – kidneys remove water from the blood When blood pressure is low – kidneys keep water volume high in blood
- 17. How is Blood Pressure Measured? b. Sphygmonometer Normal Blood Pressure: 120/80 120 – ventricles contract ( systolic ) 80 - ventricles relax ( diastolic ) c. Hypertension – excessively high blood pressure, medical consequences (140/90 or higher), can be caused by alcohol, smoking, diet and distress Hypertension Video
- 18. III. Components of Blood Blood is composed of: 55% plasma 45% blood cells red blood cells white blood cells platelets
- 19. III. Components of Blood A. Plasma Composes 55% of blood volume Centrifuged Blood 90% water and 10% dissolved gasses, wastes, nutrients, salts and proteins (Plasma Proteins) Albumins, Globulins and Fibrinogen Whole Blood Sample Sample Placed in Centrifuge Blood Sample that has been Centrifuges Plasma Platelets White Blood Cells Red Blood Cells
- 20. III. Components of Blood B. Red Blood Cells (Erythrocytes) Transport oxygen and carbon dioxide Uses Hemoglobin – iron containing protein that binds to oxygen Disc shaped to increase surface area One milliliter contains 5 million
- 21. III. Components of Blood C. White Blood Cells (Leukocytes) Fight infection 5 Types : neutrophils, eosinophils, basophils, lymphocytes and monocytes (located in lymph vessels) Located in Circulatory and Lymphatic Systems
- 22. White Blood Cells Cell Type Neutrophils Eosinophils Basophils Monocytes Lymphocytes Function Engulf and destroy small bacteria and foreign substances Attack parasites; limit inflammation associated with allergic reactions Release histamines that cause inflammation; release anticoagulants, which prevent blood clots Give rise to leukocytes that engulf and destroy large bacteria and substances Some destroy foreign cells by causing their membranes to rupture; some develop into cells that produce antibodies, which target specific foreign substances
- 23. III. Components of Blood D. Platelets (Thrombocytes) More numerous than WBC’s: 250,000 platelets in a small drop of blood Much smaller than RBC’s Are fragments of cells Made in the bone marrow Live ~ 5 days Aid in forming blood clots Adhere to site of injury and release chemicals to help blood clot
- 24. IV. Lymphatic System A. Network of nodes, vessels and organs B. Primary function = return fluid lost by the blood to the Circulatory System C. Contains fluid called Lymph D. Restricts backward flow by the use of valves E. Nodes are used to trap bacteria F. Organs Spleen Harbors Phagocytes & removes damages blood cells Thymus Location of matured T Cells Superior vena cava Lymph nodes Thymus Heart Thoracic duct Spleen Lymph vessels
- 25. V. Blood Types *AB = universal recipient (can receive all blood types) * O = universal donor (can donate to all blood types) Blood Type Antigens on RBC’s Antibodies in Plasma Can Receive Blood From… Can Donate To… A A Anti-B O and A A and AB B B Anti-A O and B B and AB AB AB None A, B, AB and O AB O none Anti-A & Anti-B O A, B, AB, and O
- 26. Blood Type of Donor A B AB O Blood Type of Recipient A B AB O Unsuccessful transfusion Successful transfusion
- 27. VI. Circulatory Problems Atherosclerosis – Condition in which lipids collect under the inner lining of damaged artery walls, eventually narrowing or blocking the artery and obstructing blood flow. Heart Murmur – Whooshing sound caused by the back flow of blood from the left ventricle across the mitral valve back into the left atrium Anemia – A decrease in number of healthy red blood cells Coronary Thrombosis – (Heart Attack) Blockage of coronary arteries preventing oxygen to reach a particular area of the heart muscle Atherosclerosis
- 28. VI. Problems Cont. Stroke – Occurs when blood vessels leading to or in the brain clot or burst causing that area of the brain to die due to lack of oxygen Sickle Cell Rheumatic Fever – A serious inflammatory condition which follows Streptococcal pharyngitis ( strep throat). Can damage valves in the heart. Leukemia – cancer that originates in the blood – causes overproduction of leukocytes Sickle Cell Anemia – Genetic disorder, resulting in misshaped red blood cells