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Duration: 75 min High School Grades: 9 - 12 Circulatory System Life Science, Human Biology CCSS, NGSS Lesson overview The circulatory system is a huge network of organs, arteries, veins and capillaries. It is responsible for the flow of blood, which carries nutrients, hormones, oxygen and other gases to and from cells. During this class, students will explore the veins and arteries in bigger detail to understand how the blood flows through their bodies. They will also learn what the components of the blood are and what functions they have. With the aid of the HoloLens AR, they will be able to observe the models in larger-than-life scale to grasp their complexity and present their findings to their peers. Learning objectives • Explain the process of flow of blood and its function. • Explore the interrelationship of structure and function in the circulatory system. • Distinguish different components of the blood and what their functions are. Keywords Aortic Valve, Arterioles, Artery, Valve, Capillary, Immune System, Oxygen, Plasma, Platelets, Pulmonary, Red Blood Cells, Veins, Venules, White Blood Cells Standards Common Core CCSS ELA-Lit. SL.9-10.1 Initiate and participate effectively in a range of collaborative discussions (one-on-one, in groups, and teacher-led) with diverse partners on grades 9-10 topics, texts, and issues, building on others' ideas and expressing their own clearly and persuasively. SL.11-12.5 NGSS HS-LS1-2 Make strategic use of digital media (e.g., textual, graphical, audio, visual, and interactive elements) in presentations to enhance understanding of findings, reasoning, and evidence and to add interest. Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms. 1. Introduction - Circulation of the blood Repeat with your students, that blood has to make a really long journey to reach on the smallest capillaries. Explain how this work by highlighting and speaking about different parts on the Lifeliqe model. Open Lifeliqe app on a tablet or PC connected to a projector and type inside the search box: “Circulation of the Blood” Open the model and highlight different parts by clicking on each label, talk about their function: 1. Heart 2. Arteries 3. Ascending Aorta 4. Inferior Vena Cava 5. Aortic Arch 6. Descending Aorta 7. Veins 8. Superior Vena Cava 9. Pulmonary Circulation Background information The circulatory system is comprised of your heart, arteries, capillaries, and veins. Blood is pushed through the body by the action of the pumping heart. With each rhythmic pump, blood is pushed under high pressure and velocity away from the heart, initially along the main artery, the aorta. The slow rate of travel through the capillary beds, which reach almost every cell in the body, assists with gas and nutrient exchange and also promotes the diffusion of fluid into the interstitial space. After the blood has passed through the capillary beds to the venules, veins, and finally to the main venae cavae, the rate of flow increases again but is still much slower than the initial rate in the aorta. Blood primarily moves in the veins by the rhythmic movement of smooth muscle in the vessel wall and by the action of the skeletal muscle as the body moves. Blood flow through the capillary beds is regulated depending on the body’s needs and is directed by nerve and hormone signals. 15 min 2. HoloLens Activity #1 - Blood Vessels This activity needs some preparation time. Put on the HoloLens and load the Lifeliqe page. Find the activity 1 in the Lesson plan Circulatory system and click on the button to create the layout. Download and open each in the 3D viewer, returning each time bact to the Edge, arrange them in the space of the class and save the layout in the slot number 1. During the class, pick a students and let him/her to put the HoloLens goggles on. Connect HoloLens to the projector using the streaming app. Instruct the student wearing HoloLens to open the Microsoft Edge, Lesson plan Circulatory system and select the “Blood Vessels- Activity 1”. He/she should follow the instructions in HoloLens and download and open the model of “composition” to be augmented in his/her vision. 10 min Let the student to study the model and its parts for some time.When he/she is ready, instruct him/her to load layout #1 to start the assessment - by tapping in close proximity of the model a new menu with four options will appear. Let him/her tap on the “load layout” button and select number 1. The student should be able to see the same model but with the labels apart and his/her task is to move the labels and position them to match the right parts of the model. The student has limited time (2 minutes) to complete the activity to make it more challenging. Alternatively, you can let the students compete - let them all try the activity and time their performance (don’t project the stream to the rest of the class, just watch it on a PC or laptop to make sure they have the labels right). The rest of the class can study the model of “Vascular Wall” in the Lifeliqe app in the meantime. Note: This approach would make this activity significantly longer (5 minutes extra per each student). Background information: A vein is a blood vessel that conducts blood toward the heart. Because they are lowpressure vessels, larger veins are commonly equipped with valves that promote the unidirectional flow of blood toward the heart and prevent backflow caused by the inherent low blood pressure in veins as well as the pull of gravity. An artery is a blood vessel that conducts blood away from the heart, so they typically have relatively thick walls that can withstand the high pressure. Veins and arteries branches into capillaries - microvessels, which enable the exchange of water, oxygen, carbon dioxide, and many other nutrients and waste substances between the blood and the tissues. 3. HoloLens Activity #2: What is the blood made of? Pick another student and let him/her to put the HoloLens goggles on (don’t project the stream). Instruct him/her to open the “What is the blood made of? - Activity 2” to play and watch the video. Let him/her describe what they see and the rest of the class can guess what’s happening. Help your students with this type of questions: What do you think you saw just happen? What is inside our veins and arteries? Is blood just a red fluid? What is the yellowish part of the liquid? Then open and project the video in the Lifeliqe app,(you can find it as the “Erythrocyte Sedimentation Rate - Video”) and observe the time-lapse of a blood sample sedimentation with students, while describing the plasma and what this kind of laboratory test is good for. 15 min Background information: Blood cells travel through the circulatory system suspended in a yellowish fluid called plasma. Plasma is the non-cellular or liquid portion of the blood that makes up about 55% of the blood’s volume. Plasma is a mixture of water, proteins, and dissolved substances. Around 90% of plasma is made of water, although the exact percentage varies depending upon the hydration levels of the individual. The proteins within plasma include antibodies and albumins. Antibodies are part of the immune system and bind to antigens on the surface of pathogens that infect the body. Albumins help maintain the body’s osmotic balance by providing an isotonic solution for the cells of the body. Many different substances can be found dissolved in the plasma, including glucose, oxygen, carbon dioxide, electrolytes, nutrients, and cellular waste products. The plasma functions as a transportation medium for these substances as they move throughout the body. Erythrocyte sedimentation is a routine laboratory test that indicates the rate of descent of erythrocytes in a sample of anticoagulated blood . According to the pioneers of this test examinations it is also known as Fahræus Westergren (FW). The sedimentation rate will depend primarily on the size of particles settling. The erythrocytes tend to form cylindrical clumps, which sediment faster than separate erythrocytes. Agglomerate support some proteins, especially fibrinogen and gamma globulins. As a result, sedimentation of blood accelerates especially in inflammations, infectious diseases, pregnancy and the like. Blood sedimentation rate in healthy individuals varies within this range: ♂ 2-5 mm / hr ♀ 3-8 mm / hr 4. HoloLens Activity #3: Blood Components When students learn what plasma is, ask them: • What about the red blood liquid? • What are the main components of blood? The average human body contains about 4 to 5 liters of blood. As a liquid connective tissue, it transports many substances through the body and helps to maintain homeostasis of nutrients, wastes, and gases. Blood is made up of red blood cells, white blood cells, platelets, and liquid plasma. Then divide the class in three groups and assign each with one blood component: 25 min 1. Red Blood cells (Erythrocytes) group 2. White blood cells (Leukocytes) group 3. Platelets (Thrombocytes) group Give students the access to the Lifeliqe app, textbooks and Internet and let them investigate: • What does red blood cell (respectively white blood cell or platelet) is? • Where is it produced? • What is their main function? • What does it look like? • What percentage of blood does it make up? Students in groups can write down their findings right into the Lifeliqe app using My Note function or you can print out the working sheet, which is located at the end of this lesson plan. With the use of the HoloLens goggles, all three models can be found and observed in the “Blood components - Activity 3”. While students are working on their research, put the HoloLens goggles on (with the projector turned off) and download all three models and their labels and arrange them in the class so students can later match each label with the right model. Pick one student-representative of each group, turn on the projection of the streaming (so the rest of the class can see what the student with HoloLens is seeing) and let them finish the activity - task of each representative is to locate the model of their component and match it with the right label. When doing so, the representative and the rest of the group should present their key findings. Encourage the rest of the class to take notes (either in the Lifeliqe app or in the printed sheet. Note: During the streaming from HoloLens, you can also take a video of each presenting group (viewed from HoloLens). Note 2: In order to use the potential of the Mixed Reality, try to use paper labels instead of virtual ones - just write the names of models on pieces of paper and position the models on a table or other surface. Then have students move the paper labels in the right position. Background information Red Blood Cells: Red blood cells, also known as erythrocytes, are by far the most common type of blood cell and make up about 45% of blood volume. Erythrocytes are produced inside of red bone marrow from stem cells at the astonishing rate of about 2 million cells every second. Erythrocytes transport oxygen in the blood through the red pigment hemoglobin. Hemoglobin contains iron and proteins joined to greatly increase the oxygen carrying capacity of erythrocytes. The high surface area to volume ratio of erythrocytes allows oxygen to be easily transferred into the cell in the lungs and out of the cell in the capillaries of the systemic tissues. White Blood Cells: White blood cells, also known as leukocytes, make up a very small percentage of the total number of cells in the bloodstream, but have important functions in the body’s immune system. There are two major classes of white blood cells: granular leukocytes and agranular leukocytes. The two major classes of agranular leukocytes are lymphocytes and monocytes. Lymphocytes include T cells and natural killer cells that fight off viral infections and B cells that produce antibodies against infections by pathogens. Monocytes develop into cells called macrophages that engulf and ingest pathogens and the dead cells from wounds or infections. Platelets: Also known as thrombocytes, platelets are small cell fragments responsible for the clotting of blood and the formation of scabs. Platelets form in the red bone marrow from large megakaryocyte cells that periodically rupture and release thousands of pieces of membrane that become the platelets. Platelets do not contain a nucleus and only survive in the body for up to a week before macrophages capture and digest them. 5. Final wrap-up of the key findings and discussion At the end of the class you can wrap up all the findings and materials explained in the classroom and set up the discussion to finalize the class. Questions for the discussion: • Name the structures of the circulatory system. • What are the functions of each type of circulatory system tissue? • What is the blood and what are its main components? Describe their functions and what you learnt from your peers. Assessment of the presentation (HoloLens activity #3) Use the following three-point rubric to evaluate students' work during this lesson: Three points Students demonstrated a deep understanding of how important scientific theories are developed; worked well with their group to conduct in-depth research; and were highly involved in the development of the class timeline. Two points Students demonstrated a satisfactory understanding of how important scientific theories are developed; worked satisfactorily with their group to conduct research; and were involved in the development of the class timeline. One point Students demonstrated little or a poor understanding of how important scientific theories are developed; did not work well with their group to conduct research; and were barely or not involved in the development of the class timeline. 10 min Printable sheet with the exercise, so students can write down their key findings: 1. Red blood cells (Erythrocyte) Group Students findings: 2. White blood cells (Leucocyte) Group Students findings: 3. Platelets (Thrombocyte) Group Students findings: