the circulatory and respiratory systems...respiratory systems unit: animal science and the industry...

The Circulatory andRespiratory Systems

Unit: Animal Science and the Industry

Problem Area: Animal Anatomy and Physiology

Lesson: The Circulatory and Respiratory Systems

� Student Learning Objectives. Instruction in this lesson should result in studentsachieving the following objectives:

1 Identify components of the respiratory system, and describe the functions of

the organs that compose the respiratory system.

2 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.

3 Define blood, and describe the components of blood.

4 Explain blood’s role in the exchange of materials throughout the body, and

describe its other functions.

5 Explain how an animal maintains an adequate supply of blood.

6 Identify the uses of blood analysis in livestock and companion animal

production.

� List of Resources. The following resources may be useful in teaching this lesson:

Corresponding E-unit(s). Danville, IL: CAERT, Inc. www.mycaert.com

� List of Equipment, Tools, Supplies, and Facilities

� Copies of sample test

� Visuals from accompanying masters

� Copies of student lab sheet


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Copyright © by CAERT, Inc. | Reproduction by subscription only. | L040128

� Terms. The following terms are presented in this lesson (shown in bold italics):

� anemia

� antibody

� arteries

� arterioles

� atrium

� bleeding

� blood

� blood analysis

� blood count

� blood poisoning

� blood transfusion

� blood typing

� capillaries

� circulatory system

� coagulation

� fibrin

� heart

� hemoglobin

� hormone

� larynx

� marrow

� pathogen

� plasma

� platelets

� red blood cells

� respiratory system

� veins

� ventricles

� venules

� white blood cells

� Interest Approach. Use an interest approach that will prepare the students for thelesson. Teachers often develop approaches for their unique class and student situations. Apossible approach is included here.

Ask students to explain the purpose of the circulatory system and to name themajor organs in it. List the purpose and organs on the board. Have studentsidentify what substance is circulated in the system. Ask students if they havescratched themselves and bled. Why is it important to avoid unprotected contactwith blood? Blood can carry diseases that can be transmitted to individuals with


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whom it comes into contact. (Note: Explain appropriate safety practices if anyblood items will be used in the class. It is best to use prepared slides of blood ifmicroscope skills will be included in the lesson.) Move from the interestapproach into the objectives and content of the lesson.

SUMMARY OF CONTENT AND

TEACHING STRATEGIES

Objective 1: Identify components of the respiratory system, and describe the func-tions of the organs that compose the respiratory system.

Anticipated Problem: What are the components of the respiratory system, and what arethe functions of the organs that compose the respiratory system?

I. The respiratory system consists essentially of lungs and the passages that enable airto 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 fluidthat bathes all living cells, removes carbon dioxide waste from cells, and helpsregulate pH.

A. Air moves into the nostrils (external openings of the air passages) and then flowspast 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 thatbeat upward, carrying mucus, dust, and particles. When air reaches the lungs, it isat body temperature and is saturated with water.

B. Hard and soft palates separate nasal cavities from the mouth. Air and foodpassages cross in the pharynx. The danger of choking, however, is offset by analternative path for breathing during congestion and increased air intake duringexercise.

C. Air flows past the pharynx through the glottis into the larynx, which is protected bythe epiglottis. At the edges of the glottis are vocal cords. As air passes across thevocal chords, tissues vibrate and create sounds. From the larynx, air flows downthe trachea to the bronchi. The larynx controls inspiration and expiration of airand prevents inhalation of foreign objects. It is essential for voice production.

D. The trachea walls are reinforced with C-shaped rings of cartilage. As food isswallowed, 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 tonasal passages. As a result, food is directed downward. The trachea divides intotwo bronchi. The C-shaped rings of cartilage diminish as bronchi branch. Withinlungs, each bronchus branches into numerous bronchioles that conduct air toalveoli.


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E. The lungs are the most important part of the respiratory system. The lungs areshaped like cones, with the base resting against the cranial side of the diaphragmand the apex within or close to the thoracic inlet. The lungs are elastic andspongy. 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 theright and left lungs in addition to an accessory, or intermediate, lobe on the rightlung.

Use a variety of methods to help students master this objective. Lead a lecture,followed by a discussion covering key points. Use VM–A and VM–B to furtherdiscuss the respiratory system. Review with students upon completion to assessunderstanding.

Objective 2: Identify components of the circulatory system (including identification ofmajor veins and arteries), and describe the functions of the organs thatcompose the circulatory system.

Anticipated Problem: What are the components of the circulatory system (includingidentification of major veins and arteries), and what are the functions of the organs thatcompose the circulatory system?

II. The circulatory system is defined as an organ system that moves substances to andfrom cells. It often helps stabilize body temperature and pH. The circulatory systemtypically consists of a heart, blood vessels, and blood.

A. Vertebrates have a closed circulatory system, which generally confines thetransport medium (blood) within its walls. The closed systems coevolved with therespiratory and lymphatic systems. In fish, blood flows in one circuit. In birds andmammals, it flows in two through a partitioned heart that works as twoside-by-side pumps. The double circuit supports the high levels of activity typical ofmost vertebrates that evolved on land.

B. A muscular heart keeps blood circulating through the animal body. The heart is afour-chambered, hollow muscle used to pump blood. It is divided into fourcompartments: 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 receivesblood. 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 inoxygen) all over the body.

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 areresilient. They expand to accommodate any sudden increase in blood volumethat results after heart contractions. Arteries are deep under the skin and haveno valves. They divide further into arterioles, which are small arteries with a


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constriction and dilation that are controlled by the nervous system to regulateblood pressure.

2. Capillaries are microscopic blood vessels with a wall formed of one layer ofsimple 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 animaleats, capillary beds of the digestive system open. Capillaries are so narrow thatred blood cells must pass through in single file. Gas, nutrient, and wasteexchange occur across thin walls. Venules are vessels that take blood fromcapillaries and join to form a vein.

3. Veins transport blood toward the heart. The wall of a vein is much thinner thanthat of arteries; there is no blood pressure. One-way valves open in the direc-tion of the heart and close to prevent back-flow.

Use a variety of methods to help students master this objective. Draw a diagramor find one on the Internet to assist students with visualizing the process. UseVM–C and VM–D to further discuss the circulatory system. Review key pointswith students and assess comprehension.

Objective 3: Define blood, and describe the components of blood.

Anticipated Problem: What is blood, and what are the components of blood?

III. Blood is the liquid in the circulatory system of an animal organism. Organisms cannotlive without blood. All animals have blood, but its nature varies from one species toanother. The amount of blood in an animal varies with the species and size of theanimal. A large animal has more blood than a small animal. An average adult humanweighing 160 pounds (73 kg) has about 5 quarts (4.7 L) of blood. (Animals that liveat high altitudes have more blood than those at lower altitudes because air at higheraltitudes has less oxygen. More blood is needed to meet the demands of the body foroxygen.)

A. Blood consists of four major components.

1. Plasma is the liquid substance in which various solid materials are suspendedand moved about. Plasma is 90 percent water. The other 10 percent consistsof dissolved substances including glucose, hormones, wastes, minerals, vita-mins, and proteins. The plasma suspends and transports the solid blood mate-rials. Plasma composes 50 to 60 percent of blood by volume. Plasma has astraw color when the solid materials are removed.

2. Red blood cells (erythrocytes) are responsible for carrying oxygen from thelungs throughout the circulatory system. The oxygen is carried by a protein partof the blood known as hemoglobin. Red blood cells have a flexible membranethat allows them to squeeze through the very smallest blood vessel. Red bloodcells do not repair themselves. New red blood cells are made in bone marrow.


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The dead red blood cells are removed by the spleen and liver. Scientists havefound that one animal may possess a trillion blood cells.

3. White blood cells (leukocytes) are responsible for fighting disease and remov-ing harmful substances from the body. Four different kinds of white blood cellsare found in blood. Some white blood cells surround and digest infectious bac-teria. Other white blood cells produce antibodies. An antibody is a kind of pro-tein that destroys bacteria, viruses, and other substances that invade thebody. Animals that are diseased produce increased numbers of white bloodcells. The pus that forms in an infected wound is a large mass of white bloodcells that has been fighting the infection.

4. Platelets (thrombocytes) are the structures in blood that are responsible forclotting. They are not complete cells and have a disk-like shape. In case of awound, platelets stick to the edge of the skin and to each other to form a scabor cover that stops the flow of blood. Without platelets, an animal might bleedto death from a wound.

B. The organs in the circulatory system have an important role in assuring good bloodcirculation. Blockages interfere with body functions. The heart is the “pump” thatsends blood out through the arteries and capillaries into the body. The bloodreturns in the veins. Circulation includes moving blood through the lungs byreceiving oxygen and giving off carbon dioxide, by the liver and spleen for cleaning,and throughout the entire body to support life processes.

Use a variety of methods to help students master this objective. Use VM–E tohelp students understand the components of blood. Many teachers havediscontinued the use of real blood in classroom exercises because of thedangers of contracting diseases. Using prepared microscope slides availablefrom a biological supply house is a good alternative.

Objective 4: Explain blood’s role in the exchange of materials throughout the body,and describe its other functions.

Anticipated Problem: What is blood’s role in the exchange of materials throughout thebody, and what are its other functions?

IV. Blood fulfills a number of functions that are essential to the well-being of anorganism.

A. Blood must flow to all parts of the body to achieve these functions.

1. Transport oxygen and carbon dioxide: Blood carries oxygen to all areas of thebody 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 andacquire 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.

2. Protects against disease: The white blood cells in blood help keep an organismhealthy and fight disease.


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3. Transport hormones: Blood carries substances known as hormones. A hor-

mone is a compound that produces a response within the body of an organ-ism. Hormones are produced by endocrine glands and are secreted into theblood. Hormones regulate growth, metabolism, reproduction, and other func-tions of a living animal.

4. Transport nutrients and wastes: Blood carries nutrients from digested food.Blood that flows in the walls of the small intestine acquires nutrients as foodmolecules. As cells use the nutrients or as cells grow and die, wastes are cre-ated. These wastes are transported by the blood to the liver for removal andexcretion.

5. Heat regulation: Blood helps regulate the temperature in an organism. Activityby muscles in the body produces heat. The heat is picked up by the blood anddistributed throughout the body. The skin may use some of the liquid in bloodas sweat.

B. Proper circulation and good blood health are essential for these functions to beachieved. Any disruption causes the organism to suffer and possibly die.

Use a variety of methods to help students master this objective. Use VM–F tooutline the major content of this objective. Have students participate byproviding information or situations with which they are familiar where blood wasa factor in disease. Students may be assigned short library or computer-basedresearch projects on blood and its role.

Objective 5: Explain how an animal maintains an adequate supply of blood.

Anticipated Problem: 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 growthfactors. These involve complex processes that occur in the body. In general, threeprocesses are involved in maintaining a supply of blood.

1. Regulation of amount: The amount of blood and proportions of materials inblood is continuously being adjusted to meet the demands of the body. Forexample, an animal that is diseased will produce an increase in white bloodcells.

2. Replacing worn cells: Damaged/worn cells and platelets must be replaced.Blood cells and platelets are produced in bone marrow. Marrow is the softsubstance in the middle of bones and may be red or yellow. Different pro-cesses are used to make red and white cells and platelets. All begin as similarcells but develop differently depending on the needs of the body.

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 inter-nal due to injury or disease of the organs or tissues. Blood plasma containsclotting (coagulation) factors. These cause the blood to coagulate. Coagula-


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tion is a complex process initiated by injured tissues giving off signals indicat-ing that bleeding is occurring. The clotting factors result in the formation ofsticky strands known as fibrin. The fibrin criss cross each other and create ablockage that stops the loss of blood from the wound. Blood also containssubstances that dissolve clots. Occasionally a clot will occur where it is notneeded, such as in an artery. The clot disrupts blood flow and can result in dis-ease and death, especially if the clot results in a heart attack or stroke.

B. Organisms that lose blood in an accident or medical procedure may be givenblood that has been taken from another animal with the same blood type. Thisprocess is known as a blood transfusion. It is more common in humans than indomesticated animals. Transfusions can transmit disease from one organism toanother. Blood transfusions should only be done by trained individuals.

Use a variety of methods to help students master this objective. Use VM–G tooutline the content of this objective. Have students give examples where bloodcoagulation failed. Some explanation on the use of human blood transfusionsmay be in order. To prevent receiving blood from another individual, a personcan provide blood that is available when it is needed. For example, a personwho will have surgery can provide blood to the hospital a couple of weeks aheadof time, which greatly reduces incompatibility or the likelihood of contractingdisease from the blood transfusion.

Objective 6: Identify the uses of blood analysis in livestock and companion animalproduction.

Anticipated Problem: What are the uses of blood analysis in livestock and companionanimal production?

VI. Blood analysis is the process of testing blood to determine its characteristics.Samples are collected and tested to determine various attributes.

A. Blood typing is a kind of analysis that is used in genetic studies. Genetic markersin the blood can be used to determine the parents of offspring. For example, theidentity of the sire of a calf can be determined by blood typing a calf. Newer DNAanalysis procedures may be replacing some uses of blood typing.

B. Blood count is a type of analysis that determines the number of red and whitecells and hemoglobin in blood. Microscopes are used to visually determine thenumber 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” overthe slide. Visual counts are made when viewed through the microscope.

C. Blood analysis is primarily used in determining the health condition of an animal.

1. Blood analysis may be used to determine the nutritional adequacy of an ani-mal’s diet. Samples of blood are taken and examined. For example, the size ofthe red blood cells of an animal indicates adequacy of nutrition. A deficiency of


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iron results in smaller than normal red blood cells. The condition caused byinadequate iron is known as anemia.

2. Blood analysis may be used to determine the presence of pathogens, whichare microscopic organisms that cause disease. Bacteria and viruses are com-mon pathogens. Analysis also indicates the proportions of red and white bloodcells. Higher amounts of white cells indicate that the body is fighting an infec-tion. Blood poisoning is a condition in the blood caused by the presence ofbacteria or fungi that cause disease. The microorganisms enter the bloodthrough an infection or wound. Good sanitation helps prevent blood poisoningin the event of an injury.

3. Other diseases can be determined with blood analysis. For example, too fewwhite cells in blood indicates a disease in the bone marrow. A very high whiteblood cell count is a sign of leukemia in humans.

Use a variety of methods to help students master this objective. Use VM–H tooutline the content of this objective. Use a resource person to describe the useand care of blood. A veterinarian or veterinary technician will be qualified todiscuss this area with the class. A physician or nurse would be appropriate, too.

� Review/Summary. The review and summary should be organized around the fourobjectives for the lesson. Call on individual students to explain the content associated witheach objective. Use observations of student performance to determine which areas need tobe retaught. A video teaching microscope can be used to show a prepared slide of blood,including white cells, red cells, and platelets. (Note: It is preferable to obtain the slide froma biological supply house.)

� Application. Use the included visual masters to apply the information presented in thelesson.

� Evaluation. Evaluation should be based on student achievement of the objectives forthe lesson. Observations of student participation during instruction and afterward in otherlessons where the subject of blood arises will be useful. The sample written test can alsobe used.

� Answers to Sample Test:

Part One: Matching

1. i

2. g

3. j

4. a

5. e

6. d

7. c


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8. h

9. f

10. b

Part Two: True or False

1. T

2. T

3. F

4. F

5. F

Part Three: Short Answer

1. Answers should include the transportation of oxygen and carbon dioxide, protectionagainst disease, transportation of hormones, transportation of nutrients and wastes,and regulation of heat.

2. Blood count is a type of analysis that determines the number of red and white cellsand hemoglobin in blood. Abnormal blood counts can be an indication of sicknessor disease.

3. Arteries, capillaries, and veins


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Sample TestName ________________________________________

The Circulatory andRespiratory Systems

� Part One: Matching

Instructions: Match the term with the correct definition.

a. blood f. hormoneb. plasma g. marrowc. platelets h. bleedingd. red blood cells i. coagulatione. white blood cells j. blood analysis

_____1. The clotting process that stops bleeding

_____2. The soft part of bones that produces blood cells

_____3. The process of testing blood to determine its characteristics

_____4. The liquid in the circulatory system of animals

_____5. Blood cells that fight disease

_____6. Blood cells that carry oxygen

_____7. The structures in blood responsible for clotting

_____8. The loss of blood due to injury or disease

_____9. A compound that produces a response in the body

____10. The liquid part of blood

� Part Two: True or False

Instructions: Write T for true or F for false.

_____1. Blood poisoning may result when bacteria or fungi enter the blood.

_____2. A blood transfusion involves taking blood from one organism and giving it to another.

_____3. Blood analysis is not useful in the study of genetics.

_____4. The respiratory system carries blood throughout the body.

_____5. Blood acquires oxygen and gives off carbon dioxide when it is circulated through theheart.


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� Part Three: Short Answer

Instructions: Complete the following.

1. What are five roles of blood in an organism?

2. What is blood count? Why is it an important procedure?

3. List the three types of blood vessels in the body.


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VM–A

RESPIRATORY TRACTOF THE HORSE


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Nasal passages

Nostril

Epiglottis

Bronchiole

Alveoli

Pharynx

Larynx

Trachea

Primary bronchi

LungsSecondary bronchus

VM–B

RESPIRATORY AND PULMONARYCIRCULATION ORGANS


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O2

CO2

TracheaAorta

Superior vena cava

Lung

Right pulmonary artery

Right bronchus

Air sacs (alveoli)

Bronchiole

Inferior vena cava

Right and left auricles

Rightpulmonary

veins

VM–C

THE CIRCULATORY SYSTEMOF A HORSE


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Arteries

Veins

Liver

Blood vessels tothe large intestine

KidneysLungs

Heart

VM–D

CROSS-SECTION OF AHORSE’S HEART


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Anterior vena cava

Right atrium

Tricuspid valve

Right ventricle

Left ventricle

Bicuspid valve

Aortic valve segment

Left auricle

Pulmonary veinsPulmonary artery

Aorta

VM–E

BLOOD COMPONENTS

� Blood—liquid in the circulatory system

� Components:

� Plasma—liquid substance containing suspended solidmaterials

� Red blood cells—carry oxygen from lungs to body and bringcarbon dioxide to lungs

� White blood cells—fight disease

� Platelets—structures in blood responsible for clotting


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VM–F

FUNCTIONS OF BLOOD

� Blood transports oxygen and carbon dioxide.

� Blood protects against disease.

� Blood transports hormones.

� Blood transports nutrient molecules and wastes.

� Blood regulates heat.


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VM–G

BLOOD SUPPLY

� The quantity and contents are continuously beingregulated by the body.

� The blood supply replaces worn cells, which occurs inbone marrow.

� The blood supply controls bleeding with the coagulationprocess.


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VM–H

BLOOD ANALYSIS

� Blood analysis—testing blood to determinecharacteristics

� Blood typing—analysis used in genetic studies

� Blood count—analysis for disease study

� Cell size—nutrition study

� Presence of pathogens—disease identification


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LS–AName ________________________________________

Swine Lung Evaluation

Purpose

The purpose of this activity is to familiarize students with the functions of the respiratorysystem.

Objectives

1. Discuss the functions of the respiratory system.

2. Identify structures of the respiratory system.

3. Identify the structures of the lungs.

Materials

� whole, fluid-preserved lungs or dried lung sections

� dissection tools

� lab sheet

Procedure

1. Find and identify the following structures:

� Larynx

� Epiglottis

� Vocal folds

� Esophagus

� Trachea—C-shaped cartilages

� Bronchi—branches off trachea into each lung, stiff with cartilage

� Visceral Pleura—shiny surface of lung produces serous fluid

� Diaphragm—torn, fibrous membrane with skeletal muscle tissue


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the circulatory and respiratory systems...respiratory systems unit: animal science and the industry...

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