Internal Systems

1. Internal Systems THE CIRCULATION SYSTEM

2. Learning Goals Specific to the CIRCULATION system: Students Will: • Explain the anatomy of the circulatory system (e.g., blood components, blood vessels, the heart) and its function in transporting substances that are vital to health • Begin to understand the relationship between the circulatory system and the respiration (most important) & digestive system • Be able to describe disorders relating to the circulatory system

3. Introduction http://www.youtube.com/watch?v=oE8tGkP5_tc

4. The Pathway of Blood

5. The Transport System Functions: • Carries nutrients to cells and wastes away from cells • Relays chemical messages throughout the body • Helps maintain acceptable levels of fluid • Important in the body’s immune system, permitting the transport of immune cells throughout the body Vascular System + Circulatory System = Cardiovascular System

6. Cardiovascular System Vascular System: System of fluid tissue that plays a role in transporting nutrients to cells in the body Circulatory System: System in which the progress of fluid is controlled by muscle movements Cardiovascular System: Circulatory system in which the vascular fluid is moved around by a pump

7. SINGLE CELLED ORGANISMS • No need for a circulatory system because oxygen can diffuse directly into them and wastes can diffuse out • Inside the cell, cytoplasm streaming moves substances around • MULTI-CELLULAR ORGANISMS • Some require circulatory systems while others do not • EX) Jellyfish take in fluid through the mouth which enters a body cavity that extends throughout the body • Cells thicker than a few layers at any point throughout the body REQUIRE a circulatory system • Ectoderm-Mesoderm-Endoderm

8. Open and Closed Circulatory Systems Open Circulatory System Blood carrying oxygen and nutrients is pumped into body cavities where it bathes the cells directly • Common in snails, insects, and crustaceans • The contraction of one or more hearts pushes blood from one sinus (body cavity) to another, and the relaxation of the heart draws blood back to the heart through open ended pours Closed Circulatory System Blood is always contained within blood vessels • Fluid circulates only in one direction, passing through the gas exchange system in the cycle • Common in earthworms, squids, octopus, vertebrates

9. Comparing Circulatory Systems FISH: 2-Chambered Heart • Blood travels through the heart only once during each complete circuit around the body • Blood travels out of the heart via the ventricle to the capillaries of the gills • From there, the oxygenated blood travels throughout the body via the dorsal artery before returning to the atrium of the heart

10. Comparing Circulatory Systems AMPHIBIAN (Frogs, toads): 3-Chambered Heart • Blood travels from the heart to the lungs, and then back to the heart before being pumped into the arteries of the body • The extra chamber though, in relation to the fish, allows a double circulation to occur

11. Comparing Circulatory Systems BIRDS AND MAMMALS: 4-Chambered Heart - Again, blood travels from the heart to the lungs, and then back to the heart before being pumped into the arteries of the body (difference is the additional chamber in the heart) • High energy requirements means we need lots of oxygen delivered quickly to the entire body, and wastes removed! • Oxygenated and deoxygenated blood must be kept completely separate

12. ADVANTAGES & DISADVANTAGES???

13. Mammalian Circulatory System 3 Primary Closed Circuits • Cardiac Circulation: • Pulmonary Circulation: • Systemic Circulation: Male: 5-6 liters of blood, Female: 4-5 liters of blood 80-90% of blood is in the systemic system, most of the rest is in pulmonary Pathway of blood through the heart Pathway of blood from heart to lungs and back Pathway from the heart to rest of the body

14. 3 Main Elements to the Circulatory System • Transport Medium: Fluid being moved around • Transport Vessels: How fluids get from one area to another • A Pumping Mechanism

15. 1. Transport Medium: BLOOD Collection of specialized cells Components of Blood • Plasma (55%): water, gases, proteins, sugars, vitamins, minerals, waste • Red Blood Cells (45%) • White Blood Cells and Platelets (<1%)

16. Red Blood Cells ERYTHROCYTES • Primary function is the transport of oxygen • What allows RBC’s to carry Oxygen? Hemoglobin! • Increases the ability of the blood to carry oxygen by a factor of almost 70 • About 280 million hemoglobin molecules are found in a single RBC • In theory, each molecule of hemoglobin can bind with 4 molecules of oxygen

17. Red Blood Cells: ERYTHROCYTES cont’d Why does blood appear red in arteries but blue in veins??? • When oxygen binds to hemoglobin it becomes oxyhemoglobingiving blood its red colour • Once oxygen is given up to the cells of the body, the shape of hemoglobin changes, causing the reflection of blue light! Shape: Biconcave

18. Red Blood Cells: ERYTHROCYTES cont’d • Oxygen forms a loose bond with the heme group, whereas CO2 forms a strong bond Disposing of CO2 45% of CO2 is carried by the erythrocytes forming carbaminohemoglobin 9% is carried in the plasma 46% combines with water to form carbonic acid (H2CO3) • This keeps the partial pressure of CO2 in the blood low so that more CO2 can diffuse out of cells. • Carbonic Acid → H+and HCO3-ions • This would increase acidity of blood but hemoglobin picks up and rids of H+ ions to maintain body pH

19. Red Blood Cells: ERYTHROCYTES cont’d Death of an ERYTHROCYTE • Live about 120 days • Travels to the liver to recycle and salvage iron • Approx. 1-2 million RBC’s replace every second Sport Training? RBC’s? Anemia?

20. White Blood Cells LEUKOCYTES • Make up approximately 1% of blood (although this can change, when?) • This can double when fighting infections (pathogens) • Have a nuclei and appear colourless (RBC’s do not) Destroying invading Microbes (Infection) • Destroyed via phagocytosis • squeeze out capillaries and move toward microbe • Engulf the microbe and release enzymes that digest the microbe and the leukocyte itself • Remaining fragments of protein from this process is known as PUS

21. White Blood Cells LYMPHOCYTES • non-phagocytic that facilitate the body’s acquired immune response • Enables the body to recognize and fend off specific pathogens • Two main types: B-cells and T-cells • Several kinds in each part of the body that contribute to different parts of the immune response **Can not only fight disease but can become a variety of cell types under different conditions**

22. Platelets • Do not contain a nucleus but produced by large nucleated cells in the bone marrow • Vital to blood clotting! • Irregularly shaped: move through the smooth blood vessels of the body but rupture when they strike a sharp edge! - torn blood vessel - this is how blood clotting is initiated

23. Plasma • Fluid portion of the blood (important) • About 90% water • Contains substances that ensure bloods well-being Plasma Proteins • Serum Globulin: antibodies to defend against disease • Fibrinogens: important for blood clotting • Serum Albumin: maintains blood volume and pressure

24. Blood Groups (Types of Blood) • Early on, blood transfusion was often unsuccessful (Until blood types were discovered) • In the early 1900’s, the major BLOOD GROUPS were identified • A • B • AB • O Universal Donor - Type O blood Universal Acceptor - Type AB blood Characterized by presence or absence of two protein markers on the walls of rbc’s

25. Blood Groups (Types of Blood) RHESUS FACTOR • Another protein marker (antigen) • If you are Rh+ then you have the protein, if you are Rh- then you do not have the protein 85% of Canadians have the antigen Rh- can donate to Rh+ with no issues however… Rh+ can usually donate to Rh- as the anti-Rh antibodies develop over two to four month period after the transfusion. A second transfusion would be deadly as the body now has the appropriate antibodies for an immediate response

26. Transport Vessels ARTERIES • Carry blood AWAY from the heart (oxygenated) • Three layers: 1. Outer: connective tissue and elastic fibers 2. Middle: thickest and contains elastic fibers and smooth muscles 3. Inner: smooth epithelial cells (reduce friction) Arterioles: smaller arteries Vasoconstriction: the narrowing of blood vessels. Less blood goes to the tissues when arterioles constrict Vasodilation: the widening of blood vessels: More blood moves to tissues when arterioles dilate

27. Transport Vessels cont’d VEINS • Carry blood TOWARDS the heart (deoxygenated) • Venules (smaller veins) come together to form veins • Less elasticity but greater capacity (2x) (larger diameter) Gravity? - Can defy gravity due to skeletal muscles and valves in veins

28. Transport Vessels Cont’d CAPILLARIES • Smallest blood vessel • Site of fluid and gas exchange between blood and body cells • Friction in capillaries slows blood down to allow nutrient and waste exchange to occur EXCEPTION: Artery Vs. Vein Pulmonary Artery: Deoxygenated blood Pulmonary Vein: Oxygenated blood

29. A Pumping Mechanism HEART • pumps about 70 times/minute • Pumps fluid through about 160,000 km of vessels • Steady flow and can adjust to changes in pressure • Life expectancy about 80 years • The size of your fist!

30. Anatomy of the Heart

31. Pathway of Blood • Superior & Inferior Vena Cava • Right atrium • Right ventricle (via atrioventricular valve) • Left & Right pulmonary arteries (via semilunar valve) • Left & Right Lungs • Left & Right pulmonary veins • Left atrium • Left ventricle (via bicuspid valve) • Aorta (via semilunar valve) • Arteries to the rest of the body

32. Heart Cont’d Contractions: - Atrium: Thin walled - Ventricle: Thick walled (left is thickest) Valves: - Tricuspid Valve (AV valve): between right atrium and ventricle - Bicuspid Valve (AV valve): between left atrium and ventricle - Semilunar Valves: between the left ventricle and aorta & between the right ventricle and pulmonary artery **These valves opening and closing produce the heart beat sound LUB = Atrioventricular valves DUB = Semilunar valves

33. Heart Cont’d • The Cardiac muscle - Myogenic Muscle: ability to contract without being stimulated by external nerves S-A node (Sinoatrial node): The pacemaker of the heart, a specialized bundle of nerves located where the venae cava enter the right atrium Nerve impulses originate in the S-A node, before travelling to the second node, the Atrioventricular node (AV node) - This AV node acts as a conductor passing nerve impulses to the Purkinje Fibers, running along the septum, and eventually to branching fibers covering the surface of the heart!

34. Heart Cont’d Recording the Heart Rate ECG: Electrocardiogram P-Wave: Atrial Contraction QRS-Wave: Ventricular Contraction T-Wave: Ventricular recovery

35. Heart Cont’d • Revisiting Heart Sounds Diastole: Relaxation (dilation) of the heart, during which the cavities of the heart fill with blood Systole: Contraction of the heart, during which blood is pushed out of the heart Blood Pressure = Systolic/Diastolic (120/80)

36. Heart Cont’d PHYSICAL ACTIVITY • Increased activity requires an increase in HR • CO2 increases in out blood • Receptors in blood vessels recognize this and send signal to medulla oblongata which releases noradrenaline • This reaches the SA node causing the node to fire more rapidly RELAXATION - Fast HR means higher blood pressure • Again this message is picked up by blood vessels which send a signal to the medulla oblongata • The medulla oblongata releases acetylcholine to slow the firing of SA node

37. Heart Cont’d • Cardiac Output • The amount of blood pumped out of the heart per unit of time (in this case per minute) Cardiac Output = HR x SV Stroke Volume (SV): The amount of blood pumped with each individual heart beat Heart Rate (HR): Number of beats/minute

38. Heart Cont’d • Heart Rate and Fitness - Max heart rate (MHR) is the fastest your heart can beat, which decreases as you get older (220-your age) Tachycardia? Bradycardia? Cardiovascular Exercise? • Enlarges the ventricular chambers • Increases dispensability of ventricles • Strengthens ventricular walls

39. Heart Cont’d • DEFECTS Problems are common at birth (valves, walls, chambers) • Septal Defect: hole in the septum (that splits the right and left ventricle) • Murmers: one or more of heart valves not closing properly • Arrhythmia: irregular heartbeat • Hypertension: (high BP) caused by an increase resistance to blood flow, which results in a sustained increase in blood pressure

40. Heart Cont’d • Plaque Build-Up • Build up in arteries can cause damage to platelets and can therefore begin to lead to a blood clot Treatment • Exercise • Better Diet • Medication • Surgery • Angioplasty: fine plastic tube inserted into artery and then and when a constricted area is located a balloon is blown up to force the vessel open • Coronary Bypass: involves removing a healthy segment of blood vessel from one part of your body and using it to go around a blockage near the heart http://www.youtube.com/watch?v=S9AqBd4RExk

41. Homeostasis • Maintenance of water balance, pH, and temperature LYMPHATIC SYSTEM • Drains all fluids from tissues and returns them to the venous system • The water and chemicals in interstitial fluid comes from the heart and must be returned to maintain proper balance • Fine network of small lymph capillaries that branch throughout soft tissue • This network moves lymph to thoracic or right lymphatic duct

42. Homeostasis • Thoracic Duct • empties into venous system at left jugular vein from the neck and the left subclavian vein from the arm (drains most of body but heart, lungs and upper right body) Right Lymphatic Duct • Empties at junction of the right jugular vein and the right subclavian vein • Lymph Nodes • small round structures located on medium and large size veins (groin, neck, abdomen, armpit). • filter particles from lymph before it enters blood, and lymphocytes act as macrophages. • Tonsils: swelling due to overuse