Transport & Circulation

1. Transport & Circulation • Griffin Van, Catherine Vernon, & Brandon George

2. Transport in Invertebrates • Certain invertebrates have a thin body wall which makes it unnecessary for a circulatory system to exist, which includes but is not limited to (sponges, cnidarians, and flatworms). • Cells are either part of an external layer or line the gastro-vascular cavity. • Each cell is exposed to water and can independently exchange gases and rid its self of wastes.

4. Invertebrates with a Circulatory System • Most animals have a circulatory system that serves the needs of the cells. • The circulatory system transports oxygen and nutrients, such as glucose and amino acids, to the cells. • There are two type of circulatory fluids • Blood: which is always contained in blood vessels • Hemolymph: flows into a body cavity called a hemocoel, (a hemolymph is a mixture of blood and tissue fluid)

5. Open vs. Closed Circulatory systems • Open Circulatory Systems • “The open circulatory system is common to mollusks and arthropods. Open circulatory systems (evolved in crustaceans, insects, mollusks and other invertebrates) pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood.” • Hemolymph is only seen in animals with an open circulatory system, which consists of blood vessels and open spaces

7. Open vs. Closed Circulatory Systems • Closed Circulatory Systems • “Vertebrates, and a few invertebrates, have a closed circulatory system. Closed circulatory systems have the blood closed at all times within vessels of different size and wall thickness. In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities.”

9. Extra Credit • Which of the following is a mixture of blood and tissue fluid? • A. ostia • B. hemolymph • C. gastro-vascular cavity • D. hemocoel 9

10. Transport in Vertebrates • Cardiovascul • Cardiovascular system • In all vertebrates • Closed circulatory system • Strong muscular heart in atria, receive blood and muscular ventricles pump blood through the blood vessels • three types of blood vessels: • arteries, carry blood away from heart • capillaries, exchange materials with tissue fluid • veins, return blood to the heart 9

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13. Evolution • Fish have an inefficient one circuit pathway because they have low blood pressure oxygen leaves the gills. • One atrium and one ventricles • The ventricle pumps and sends blood to gills (gas exchange) • After passing through the gills it goes back to the dorsal aorta and blood is pumped through out the body • Veins return oxygen poor blood back to a sinus venosus chamber that leads to the atrium and the atrium pumps blood back to the ventricle 12

14. Evolution cont. • Most vertebrates have a two circuit system; that has the systematic circuit (blood to lungs) and the pulmonary circuit (blood to lungs). This is and adaption to breathing air on land. • In birds and mammals, the heart is in two halves. Left and right, right pumps blood to the lungs and the right is larger and pumps it to the rest of the body. This is advantageous because the blood pressure is in balance. 13

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16. Blood • The functions of blood: • 1) Transports gases, nutrients, waste products, and hormones throughout the body • 2) Helps destroy pathogenic microorganisms • 3)Distributes antibodies that are important in immunity • 4) Aids in maintaining water balance and PH • 5) Helps regulate body temperature • 6) Carries platelets and factors that ensure clotting and prevent blood loss • (Mader, 606)

17. Composition of Blood in Humans • Two main Portions: • Plasma- • Is about 93% water and is then composed of proteins, nutrients, salts and wastes. • It serves to hold the blood cells in suspension • Each microliter (µL; or mm³) of human blood contains 5-6 million red cells, and there are about 25 trillion in the body’s ≈5.6L of blood.

18. Blood: Plasma • Protiens and salts serve to maintain the bloods optimal PH of ≈7.4, any significant changes in this PH could be catastrophic • Additionally, salts and proteins uphold blood’s osmotic pressure so that water has an automatic tendency to enter blood capillaries • As blood enters the capillary bed on the arteriole end, the blood pressure in the capillary vessel is greater than the osmotic pressure of the blood in the vessel. The net result is that fluid moves from the vessel to the body tissue.

19. Plasma Cont. • Plasma Proteins make up about 7%-8% of plasma itself, they include but are not limited to: • Albumin- the most abundant plasma protein, which transports bilirubin (a product that results from the breakdown of hemoglobin) • Regulatory Proteins- transport enzymes, proenzymes ( the precursor to enzymes), and hormones • Globulins- ex: lipoproteins- which transport cholesterol

20. Blood: Formed Elements • Red Blood Cells (erythrocytes) • The average human adult has about 25 trillion red blood cells in their body • In each of these cells there is about 250 million hemoglobin molecules, hemoglobin is the iron containing element of blood that transports oxygen from the lungs to the rest of the body • Red blood cells are continuously being manufactured in the red bone marrow of the skull, the ribs and the vertebrae. • Erythroprotein, a hormone produced by the kidneys serves to stimulate the production of red blood cells

22. Blood: Formed Elements • White Blood Cells (Leukocytes) • Differ from Red Blood cells in that they lack hemoglobin, the component of blood that gives it the color red, because of this White Blood cells appear translucent under a microscope.White blood cells spend most of their time outside the circulatory system, patrolling interstitial fluid and the lymphatic system. • Types: • Neutrophils- a type of white blood cell that phagocytizes foreign material at the sight of infection

23. Types of White Blood Cells continued. • Monocytes- are very similar to neutrophils: however, they can become macrophages (cells that digest pathogens and stimulate lymphocytes) and can produce antigens(a substance that signals the production of antibodies (a Y-shaped protein that signals other parts of the immune system to attack or directly neutralizes the threat itself)

25. Types of White Blood Cells continued. • Lymphocytes- are white blood cells that are divided into large and small lymphocytes • Small Lymphocytes: Include T and B cells • T cells attack infected cells that contain viruses • B cells contain a protein known as a B cell Receptor, which allows the cell to bind with a certain antigen

27. Esinophils- are white blood cells that are essential in releasing enzymes that fight parasites and destroy allergens • Basophils- are the least common white blood cells, they contain heparin (an anticoagulant), and vasodilator histamine which promotes blood flow to tissues

28. Platelets:(thrombocytes) • Form as a result of the breaking up of megakaryocytes found in red bone marrow (cytokinetic fragmentation). • About 200 billion are produced per day • They are major components of blood coagulation • Third cellular component of blood, along with erythrocytes and leukocytes.

30. Blood Clotting • Platelets serve as a temporary seal for the damaged part of the vessel. • Platelets soon release a clotting factor known as prothrombin activator which converts prothrombin to thrombin • Thrombin is an enzyme that creates two amino acid chains from each fibrinogen molecule. These fragments join end to end and form fibrins. • After blood vessel repair is initiated, the enzyme plasmin, destroys the fibrin network

32. Antibiotics • Chemicals produced by microorganisms that are used to fight or kill unwanted organisms • Penicilium-is a fungus that makes penicillin which kills bacteria

33. ABO System • There are four types of blood: A,B, AB, and O.

34. Type AB blood is considered a universal recipient • Type O blood is considered a universal donor • A person with A or B blood must receive blood from either their own blood type, or O. • If the wrong blood type is given to a recipient, agglutination may occur which is the clumping of the red blood cells

35. Hemolytic Disease of the Newborn (HDN) • Is a disease seen in newborn children where anti RH antibodies cross a placenta and destroy the babies red blood cells. • This disease can be fatal if immediate blood transfusion does not occur

36. AIDS • Acquired immune deficiency is a syndrome caused by HIV (Human immunodeficiency) • Cause- HIV virus affects a certain lymphocyte that plays a vital role in antibody production, this weakens the immune system and causes the body to be vulnerable to pathogens • Transmission- HIV can only be transferred through bodily fluids from an infected person, as the virus is short lived and cannot break through the skin • Cure- There is no cure; however, there are medications that can help reduce HIV in the body

37. Extra Credit • Which type of blood cell fights infection? • Least common white blood cell that is a component of blood coagulation? • A. basophil • B. monocyte • C. macrophage • D. esinophil 37

38. The Transport System

39. Types of circulatory systems • Some invertebrates have no circulatory system. • Many invertebrates have an open circulatory system. • Some invertebrates have a closed circulatory system. • All vertebrates have a closed circulatory system.

40. Blood vessels in vertebrates • Vertebrates have three main types of blood vessels. • Arteries, which carry blood away from the heart, and typically carry oxygenated blood. • Arteries are characterized by branching, forming smaller arterioles • Arterioles ultimately form microscopic capillaries • Capillaries, which enable the actual exchange of water and chemicals between the blood and the tissues. • Capillaries merge to form venules, and then veins • Veins, which carry blood from the capillaries back toward the heart.

41. Blood vessel wall • Arteries and veins have three layers, but the middle layer is thicker in the arteries than it is in the veins: • Tunica intima (thinnest layer): single layer of simple squamous endothelial cells glued by a polysaccharide intercellular matrix. • Tunica media (thickest layer in arteries): circularly arranged elastic fiber, connective tissue, and polysaccharide substance, usually rich in vascular smooth muscle (arteries). • Tunica adventitia (thickest layer in veins): entirely made of connective tissue and contains nerves

42. Structure

43. Blood vessels • The thick walls of arteries and veins prevent passage of materials; the walls of capillaries are so thin that materials pass relatively easily. • Smooth muscle in the walls of arteries results in vasoconstriction or vasodilatation, necessary to maintain appropriate blood pressure and blood supplies. • Vasoconstriction (narrowing of blood vessels): When blood vessels constrict, the flow of blood is restricted or decreased, thus, retaining body heat or increasing vascular resistance. • Vasodilatation (widening of blood vessels): when blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance.

44. Each vertebrate class exhibits different adaptations of the heart and circulation

45. The human heart • The human heart is well adapted for pumping blood. • The heart is surrounded by the pericardium, a fluid filled sac, composed of dense connective tissue. • The smooth, inside lining of the heart, the endocardium, is composed of cardiac muscle fibers and collagen fibers. • The middle layer of the heart muscle is called the myocardium. • The interartial septum divides the atria; the interventricular septum divides the ventricles. • Valves prevent backflow of blood.

47. Relative wall thickness in the heart • Left Ventricle: Very thick wall, since is has to pump blood at a very high pressure to the whole body.Right Ventricle: Somewhat thick wall because it has to pump blood at a high pressure to the lungs.Right atrium/ left atrium: Thin walls, as it only has to pump blood to the ventricles.

48. Coronary Arteries • Coronary arteries supply heart muscle with oxygen and nutrients. • The vessels that deliver oxygen-rich blood to the myocardium are known as coronary arteries. • Right coronary artery, left anterior descending coronary artery, circumflex coronary artery, left main coronary artery •  These arteries, when healthy, are capable of auto-regulation to maintain coronary blood flow at levels appropriate to the needs of the heart muscle. • The coronary arteries are the only source of blood supply to the myocardium. •  The vessels that remove the deoxygenated blood from the heat muscle are known as cardiac veins.  • Great cardiac vein, the middle cardiac vein, the small cardiac vein, and the anterior cardiac vein

49. Fun fact • An average heart pumps 2.4 ounces (70 milliliters) per heartbeat. And, as we already mentioned, an average heartbeat is 72 beats per minute. Therefore an average heart pumps 1.3 gallons (5 Liters) per minute. In other words it pumps 1,900 gallons (7,200 Liters) per day, almost 700,000 gallons (2,628,000 Liters) per year, or 48 million gallons (184,086,000 liters) by the time someone is 70 years old. That's not bad for a 10-ounce pump.

50. The human heart • The natural pacemaker of the heart is called the sinoatrial node (SA node) and it is located in the right atrium. The heart also contains specialized fibers that conduct the electrical impulse from the pacemaker to the rest of the heart. • The heart rate is regulated by the nervous system, with a normal human heart rate of about 72 beats/minute. • Cardiac output varies with the body’s need. • Sympathetic nerves increase heart rate and increases the force of contraction. • The parasympathetic nerves do the opposite.