Animal, Plant & Soil Science

1. Animal, Plant & Soil Science Lesson C2-6 The Circulatory and Respiratory Systems

2. Interest Approach • Ask students to explain the purpose of the circulatory system and to name the major organs in it. List the purpose and organs on the board. Have students identify what substance is circulated in the system. Ask students if they have scratched themselves and bled. Why is it important to avoid unprotected contact with blood? Blood can carry diseases that can be transmitted to individuals with whom it comes into contact. (Note: Explain appropriate safety practices if any blood items will be used in the class. It is best to use prepared slides of blood if microscope skills will be included in the lesson.) Move from the interest approach into the objectives and content of the lesson.

3. Objectives • Identify components of the respiratory system, and describe the functions of the organs that compose the respiratory system. • Identify components of the circulatory system (including identification of major veins and arteries), and describe the functions of the organs that compose the circulatory system.

4. Objectives • Define blood, and describe the components of blood. • Explain blood’s role in the exchange of materials throughout the body, and describe its other functions. • Explain how an animal maintains an adequate supply of blood. • Identify the uses of blood analysis in livestock and companion animal production.

5. anemia antibody arteries arterioles atrium bleeding blood blood analysis blood count blood poisoning blood transfusion blood typing capillaries circulatory system coagulation fibrin heart hemoglobin Terms

6. hormone larynx marrow pathogen plasma platelets red blood cells respiratory system veins ventricles venules white blood cells Terms

7. What are the components of the respiratory system, and what are the functions of the organs that compose the respiratory system? • The respiratory system consists essentially of lungs and the passages that enable air to enter and exit the lungs. • These passages include the nostrils, nasal cavity, pharynx, larynx, and trachea. • The respiratory system rapidly delivers oxygen to the tissue fluid that bathes all living cells, removes carbon dioxide waste from cells, and helps regulate pH.

9. What are the components of the respiratory system, and what are the functions of the organs that compose the respiratory system? • A. Air moves into the nostrils (external openings of the air passages) and then flows past the pharynx to the trachea, bronchi, and lungs. • This process filters debris, warms air, and adds moisture. • The trachea and bronchi are lined with cilia that beat upward, carrying mucus, dust, and particles. • When air reaches the lungs, it is at body temperature and is saturated with water.

10. What are the components of the respiratory system, and what are the functions of the organs that compose the respiratory system? • B. Hard and soft palates separate nasal cavities from the mouth. • Air and food passages cross in the pharynx. • The danger of choking, however, is offset by an alternative path for breathing during congestion and increased air intake during exercise.

11. What are the components of the respiratory system, and what are the functions of the organs that compose the respiratory system? • C. Air flows past the pharynx through the glottis into the larynx, which is protected by the epiglottis. • At the edges of the glottis are vocal cords. • As air passes across the vocal chords, tissues vibrate and create sounds. • From the larynx, air flows down the trachea to the bronchi. • The larynx controls inspiration and expiration of air and prevents inhalation of foreign objects. • It is essential for voice production.

12. What are the components of the respiratory system, and what are the functions of the organs that compose the respiratory system? • D. The trachea walls are reinforced with C-shaped rings of cartilage. • As food is swallowed, the larynx rises, and the glottis is closed by a flap of tissue called the “epiglottis.” • The backward movement of the soft palate covers the entrance to nasal passages. • As a result, food is directed downward. • The trachea divides into two bronchi. • The C-shaped rings of cartilage diminish as bronchi branch. • Within lungs, each bronchus branches into numerous bronchioles that conduct air to alveoli.

14. What are the components of the respiratory system, and what are the functions of the organs that compose the respiratory system? • E. The lungs are the most important part of the respiratory system. • The lungs are shaped like cones, with the base resting against the cranial side of the diaphragm and the apex within or close to the thoracic inlet. • The lungs are elastic and spongy.

15. What are the components of the respiratory system, and what are the functions of the organs that compose the respiratory system? • They are divided into lobes by deep fissures in the ventral part of the lung. • The divisions can vary by species. • For example, the horse has no real subdivision, but most domestic animals have a cranial lobe and a caudal lobe on both the right and left lungs in addition to an accessory, or intermediate, lobe on the right lung.

16. What are the components of the circulatory system, and what are the functions of the organs that compose the circulatory system? • The circulatory system is defined as an organ system that moves substances to and from cells. • It often helps stabilize body temperature and pH. • The circulatory system typically consists of a heart, blood vessels, and blood.

18. What are the components of the circulatory system, and what are the functions of the organs that compose the circulatory system? • A. Vertebrates have a closed circulatory system, which generally confines the transport medium (blood) within its walls. • The closed systems coevolved with the respiratory and lymphatic systems. • In fish, blood flows in one circuit. • In birds and mammals, it flows in two through a partitioned heart that works as two side-by-side pumps. • The double circuit supports the high levels of activity typical of most vertebrates that evolved on land.

19. What are the components of the circulatory system, and what are the functions of the organs that compose the circulatory system? • B. A muscular heart keeps blood circulating through the animal body. • The heart is a four-chambered, hollow muscle used to pump blood. • It is divided into four compartments: the left and right ventricles and the left and right atria. • Ventricles pump blood into arteries. • The atrium is the chamber of the heart that receives blood. • The right side of the heart pumps deoxygenated blood (blood low in oxygen) to the lungs. • The left side of the heart pumps oxygenated blood (blood rich in oxygen) all over the body.

21. What are the components of the circulatory system, and what are the functions of the organs that compose the circulatory system? • C. There are three kinds of blood vessels: arteries, capillaries, and veins. • 1. Arteries carry blood away from the heart. • Arteries have thick walls that are resilient. • They expand to accommodate any sudden increase in blood volume that results after heart contractions. • Arteries are deep under the skin and have no valves. • They divide further into arterioles, which are small arteries with a constriction and dilation that are controlled by the nervous system to regulate blood pressure.

22. What are the components of the circulatory system, and what are the functions of the organs that compose the circulatory system? • 2. Capillaries are microscopic blood vessels with a wall formed of one layer of simple squamous cells. • Exchange with tissue fluid takes place in capillaries. • Capillary beds are so prevalent that, in humans, all cells are within 60 to 80 m of a capillary. • Only five percent are open at one time. • When an animal eats, capillary beds of the digestive system open.

23. What are the components of the circulatory system, and what are the functions of the organs that compose the circulatory system? • Capillaries are so narrow that red blood cells must pass through in single file. • Gas, nutrient, and waste exchange occur across thin walls. • Venules are vessels that take blood from capillaries and join to form a vein.

24. What are the components of the circulatory system, and what are the functions of the organs that compose the circulatory system? • 3. Veins transport blood toward the heart. • The wall of a vein is much thinner than • that of arteries; there is no blood pressure. • One-way valves open in the direction of the heart and close to prevent back-flow.

25. What is blood, and what are the components of blood? • Blood is the liquid in the circulatory system of an animal organism. • Organisms cannot live without blood. • All animals have blood, but its nature varies from one species to another. • The amount of blood in an animal varies with the species and size of the animal.

26. What is blood, and what are the components of blood? • A large animal has more blood than a small animal. • An average adult human weighing 160 pounds (73 kg) has about 5 quarts (4.7 L) of blood. • (Animals that live at high altitudes have more blood than those at lower altitudes because air at higher altitudes has less oxygen. More blood is needed to meet the demands of the body for oxygen.)

27. What is blood, and what are the components of blood? • A. Blood consists of four major components. • 1. Plasma is the liquid substance in which various solid materials are suspended and moved about. • Plasma is 90 percent water. • The other 10 percent consists of dissolved substances including glucose, hormones, wastes, minerals, vitamins, and proteins.

28. What is blood, and what are the components of blood? • The plasma suspends and transports the solid blood materials. • Plasma composes 50 to 60 percent of blood by volume. • Plasma has a straw color when the solid materials are removed.

29. What is blood, and what are the components of blood? • 2. Red blood cells (erythrocytes) are responsible for carrying oxygen from the lungs throughout the circulatory system. • The oxygen is carried by a protein part of the blood known as hemoglobin. • Red blood cells have a flexible membrane that allows them to squeeze through the very smallest blood vessel. • Red blood cells do not repair themselves. • New red blood cells are made in bone marrow. • The dead red blood cells are removed by the spleen and liver. • Scientists have found that one animal may possess a trillion blood cells.

30. What is blood, and what are the components of blood? • 3. White blood cells (leukocytes) are responsible for fighting disease and removing harmful substances from the body. • Four different kinds of white blood cells are found in blood. • Some white blood cells surround and digest infectious bacteria.

31. What is blood, and what are the components of blood? • Other white blood cells produce antibodies. • An antibody is a kind of protein that destroys bacteria, viruses, and other substances that invade the body. • Animals that are diseased produce increased numbers of white blood cells. • The pus that forms in an infected wound is a large mass of white blood cells that has been fighting the infection.

32. What is blood, and what are the components of blood? • 4. Platelets (thrombocytes) are the structures in blood that are responsible for clotting. • They are not complete cells and have a disk-like shape. • In case of a wound, platelets stick to the edge of the skin and to each other to form a scab or cover that stops the flow of blood. • Without platelets, an animal might bleed to death from a wound.

33. What is blood, and what are the components of blood? • B. The organs in the circulatory system have an important role in assuring good blood circulation. • Blockages interfere with body functions. • The heart is the “pump” that sends blood out through the arteries and capillaries into the body. • The blood returns in the veins. • Circulation includes moving blood through the lungs by receiving oxygen and giving off carbon dioxide, by the liver and spleen for cleaning, and throughout the entire body to support life processes.

34. What is blood’s role in the exchange of materials throughout the body, and what are its other functions? • Blood fulfills a number of functions that are essential to the well-being of an organism. • A. Blood must flow to all parts of the body to achieve these functions.

35. What is blood’s role in the exchange of materials throughout the body, and what are its other functions? • 1. Transport oxygen and carbon dioxide: Blood carries oxygen to all areas of the body and acquires carbon dioxide from the respiration process in the cells. • Blood that is being sent out passes by the lungs to give off carbon dioxide and acquire oxygen. • If an animal is cut, blood heavy with oxygen will be bright red; meanwhile, blood that has picked up carbon dioxide is reddish-brown.

36. What is blood’s role in the exchange of materials throughout the body, and what are its other functions? • 2. Protects against disease: • The white blood cells in blood help keep an organism healthy and fight disease. • 3. Transport hormones: Blood carries substances known as hormones. • A hormone is a compound that produces a response within the body of an organism. • Hormones are produced by endocrine glands and are secreted into the blood. • Hormones regulate growth, metabolism, reproduction, and other functions of a living animal.

37. What is blood’s role in the exchange of materials throughout the body, and what are its other functions? • 4. Transport nutrients and wastes: Blood carries nutrients from digested food. • Blood that flows in the walls of the small intestine acquires nutrients as food molecules. • As cells use the nutrients or as cells grow and die, wastes are created. • These wastes are transported by the blood to the liver for removal and excretion.

38. What is blood’s role in the exchange of materials throughout the body, and what are its other functions? • 5. Heat regulation: Blood helps regulate the temperature in an organism. • Activity by muscles in the body produces heat. • The heat is picked up by the blood and distributed throughout the body. • The skin may use some of the liquid in blood as sweat.

39. What is blood’s role in the exchange of materials throughout the body, and what are its other functions? • B. Proper circulation and good blood health are essential for these functions to be achieved. • Any disruption causes the organism to suffer and possibly die.

40. How does an animal maintain an adequate supply of blood? • V. The body of an organism must have adequate blood to function and be healthy. • A. The production of blood cells and materials is regulated by hematopoietic growth factors. • These involve complex processes that occur in the body. • In general, three processes are involved in maintaining a supply of blood.

41. How does an animal maintain an adequate supply of blood? • 1. Regulation of amount: The amount of blood and proportions of materials in blood is continuously being adjusted to meet the demands of the body. • For example, an animal that is diseased will produce an increase in white blood cells.

42. How does an animal maintain an adequate supply of blood? • 2. Replacing worn cells: Damaged/worn cells and platelets must be replaced. • Blood cells and platelets are produced in bone marrow. • Marrow is the soft substance in the middle of bones and may be red or yellow. • Different processes are used to make red and white cells and platelets. • All begin as similar cells but develop differently depending on the needs of the body.

43. How does an animal maintain an adequate supply of blood? • 3. Controlling bleeding: Bleeding is the loss of blood due to injury or disease. • Bleeding may be on the skin due to a scratch or cut, or bleeding may be internal due to injury or disease of the organs or tissues. • Blood plasma contains clotting (coagulation) factors. • These cause the blood to coagulate.

44. How does an animal maintain an adequate supply of blood? • Coagulation is a complex process initiated by injured tissues giving off signals indicating that bleeding is occurring. • The clotting factors result in the formation of sticky strands known as fibrin. • The fibrin criss cross each other and create a blockage that stops the loss of blood from the wound.

45. How does an animal maintain an adequate supply of blood? • Blood also contains substances that dissolve clots. • Occasionally a clot will occur where it is not needed, such as in an artery. • The clot disrupts blood flow and can result in disease and death, especially if the clot results in a heart attack or stroke.

46. How does an animal maintain an adequate supply of blood? • B. Organisms that lose blood in an accident or medical procedure may be given blood that has been taken from another animal with the same blood type. • This process is known as a blood transfusion. • It is more common in humans than in domesticated animals. • Transfusions can transmit disease from one organism to another. • Blood transfusions should only be done by trained individuals.

47. What are the uses of blood analysis in livestock and companion animal production? • Blood analysis is the process of testing blood to determine its characteristics. • Samples are collected and tested to determine various attributes.

48. What are the uses of blood analysis in livestock and companion animal production? • A. Blood typing is a kind of analysis that is used in genetic studies. • Genetic markers in the blood can be used to determine the parents of offspring. • For example, the identity of the sire of a calf can be determined by blood typing a calf. • Newer DNA analysis procedures may be replacing some uses of blood typing.

49. What are the uses of blood analysis in livestock and companion animal production? • B. Blood count is a type of analysis that determines the number of red and white cells and hemoglobin in blood. • Microscopes are used to visually determine the number of each cell by using a grid slide. • Only a drop is needed for a blood count. • A substance is added to the blood to prevent coagulation so that it will “flow” over the slide. • Visual counts are made when viewed through the microscope.

50. What are the uses of blood analysis in livestock and companion animal production? • C. Blood analysis is primarily used in determining the health condition of an animal.