Unit 1 - Aegis Flow PDF

UNIT 1 AEGISFLOW (Circulatory and Immune System) Grade 8 What are these objects ? MACHINES!!!!  Think-pair-share ACTIVITY State the function of each machine. Are each of these objects, independent entity or an assortment of parts? Justify...

UNIT 1 AEGISFLOW (Circulatory and Immune System) Grade 8 What are these objects ? MACHINES!!!!  Think-pair-share ACTIVITY State the function of each machine. Are each of these objects, independent entity or an assortment of parts? Justify What are the different tasks performed by the human body that enables a person to live???? Draw a mind map Key Concept SYSTEM Related Concept BALANCE & FUNCTION Global Context IDENTITIES AND RELATIONSHIPS: Lifestyle choices  Statement Of Inquiry Knowing how a system functions helps us maintain its balance through appropriate lifestyle choices.  If transport in plant takes place through xylem, how does it happen in humans? Do we have tissue to transport materials in our body? CIRCULATORY SYSTEM It is a complex network responsible for the transport of blood, nutrients, oxygen, carbon dioxide, hormones, and other substances throughout the body. Circulatory systems generally have three main features: Fluid : (blood or hemolymph) that transports materials. Blood vessels: A network in which the fluid travels. Heart: a muscular organ to pump the fluid through the vessels.  What did you observe ? After watching the video, what is one major component of blood that you identify ?  Summary of the COMPONENTS OF BLOOD Solids Plasma (liquid part) The cells present in designed to carry the blood cells the blood and all the following substances red blood cells water white blood cells fibrinogen (a protein) platelets albumin (a protein) antibodies digested foods mineral salts vitamins cell waste (urea, CO2) hormones  WHAT IS ACTUALLY IN YOUR BLOOD? What can you see here?  Erythrocytes Blood: Components Plasma The liquid portion of the blood. Erythrocytes - red blood cells Carry oxygen (and some carbon dioxide) Leucocytes Leucocytes - white blood cells Protect the body against infections Two types: phagocytes and lymphocytes Platelets Platelets Small cell fragments that assist in clotting  Red blood cells Function Carry oxygen from the lungs to the tissues for respiration (technically, it also carries carbon dioxide) Features Biconcave disc shape which increases their surface area No nucleus to increase oxygen carrying capacity Contains haemoglobin, which binds to oxygen to form oxyhaemoglobin  Red blood cells contains haemoglobin. An iron containing protein capable of binding oxygen (also cardondioxide molecules), and transporting them.  At the lungs Haemoglobin + Oxygen Oxyhaemoglobin At the tissues At the tissues Haemoglobin + Carbon dioxide carbamino-haemoglobin At the lungs  Carbon monoxide Poisoning Carbon monoxide combines with haemoglobin more easily and is irreversible. This reduces oxygen carrying capacity of the RBCs. irreversible Haemoglobin + Carbon monoxide carboxy-haemoglobin Prolonged exposure to carbon monoxide can suffocate a person and may lead to death.  White Blood Cells (Leucocytes) They are larger than red cells, but are fewer in number. They have no fixed shape. There are many types of leucocytes, two major types are a) lymphocytes, which are made by lymph glands, and fighting infection by producing antibodies. b) phagocytes, which engulf pathogens and digest them (in a process called phagocytosis). LYMPHOCYTE - Smaller than phagocyte - Large, dark round nucleus - Less cytoplasm. PHAGOCYTE - Larger than lymphocyte - Nucleus appears lobed - More cytoplasm. Draw diagrams of the two main types of WBCs – phagocytes and lymphocytes  Platelets Platelets are small cell fragments involved in the clotting process. Platelets Create a Comic Strip or Graphic Organizer to Describe the Process of Blood Clotting Identify Key Steps and Illustrate and Describe Each Components (5 minutes): Step (10 minutes): When a blood vessel get damaged – platelets gather and stick to the broken blood vessel wall at the injury site. They get activated. They convert the soluble protein fibrinogen into the insoluble protein fibrin. Then they make a plug with fibrin threads and stop bleeding. This process is known as clotting. Clotting Help prevent blood loss and prevent the entry of pathogens.  Process of blood clotting. Cut occurs→ platelets form a temporary plug Clotting Factors attach to the plug and bring about the conversion of Fibrinogen to fibrin Inactive soluble fibrinogen is converted to active insoluble fibrin threads which forms a mesh that traps other cells like RBCs and WBCs. The blood clot stops the bleeding & prevents entrance of pathogens Clot dries & hardens and makes a scab. New skin forms. Blood clot under the microscope  Blood Smear It is a laboratory technique used to examine the characteristics and types of blood cells. It involves spreading a drop of blood thinly across a microscope slide, staining the cells, and then viewing them under a microscope. This helps to diagnose various medical conditions and blood disorders. Staining and observation of blood smear. Commonly-used stain is Giemsa stain. Red blood cells Pink Platelets Pale pink White blood cell cytoplasm Pale blue White blood cell nuclei Magenta Blood cells can be 10 μm in size or less. Observing them will require high power magnification.  Role PLAY- BLOOD GROUPING You are a doctor, there is a patient who met with an accident, its an emergency case. After checking, you realize….that he has lost a lot of blood. Who can be the donor for the patient? The father, mother or sibling? The doctor asks this question to the entire class.  Blood grouping & Blood Types There are 4 main Blood Types: Type A, Type B, Type AB, and Type O How common is your blood type? 46.1% 38.8% 11.1% 3.9%  ABO System The differences in human blood - presence or absence of certain proteins called antigens and antibodies. The antigens are located on the surface of the red blood cells and the antibodies are in the blood plasma. Mixing incompatible blood groups leads to blood clumping or agglutination, which is dangerous for individuals. Nobel Laureate Karl Landsteiner was involved in the discovery of both the AB0 and Rh blood groups. Blood group A If you belong to the blood group A, you have A antigens on the surface of your red blood cells and B antibodies in your blood plasma. Blood group B If you belong to the blood group B, you have B antigens on the surface of your red blood cells and A antibodies in your blood plasma. Blood group AB If you belong to the blood group AB, you have both A and B antigens on the surface of your red blood cells and no A or B antibodies at all in your blood plasma. Blood group O If you belong to the blood group 0 (null), you have neither A or B antigens on the surface of your red blood cells but you have both A and B antibodies in your blood plasma. Rh Factors Scientists sometimes study Rhesus monkeys to learn more about the human anatomy because there are certain similarities between the two species. While studying Rhesus monkeys, a certain blood protein was discovered. This protein is also present in the blood of some people. Other people, however, do not have the protein. The presence of the protein, or lack of it, is referred to as the Rh (for Rhesus) factor. A+ A- If your blood does contain the protein, your blood is said to be Rh positive (Rh+). B+ B- If your blood does not contain the protein, your blood is said AB+ AB- to be Rh negative (Rh-). O+ O- Rh Factor Many people also have a Rh factor on the red blood cell's surface This is also an antigen and those who have it are called Rh+. Those who haven't are called Rh-. But a person with Rh- blood can develop Rh antibodies in the blood plasma if he or she receives blood from a person with Rh+ blood, whose Rh antigens can trigger the production of Rh antibodies. A person with Rh+ blood can receive blood from a person with Rh- blood without any problems. Blood grouping procedure To determine a person's blood type, a sample of their blood is mixed with purified antibodies against type A and B blood and the Rh factor. Observing whether the blood cells agglutinate (clump together) helps identify the blood type: 1. Anti-A antibodies: Added to the blood sample. If agglutination occurs, the blood contains A antigens. 2. Anti-B antibodies: Added to the blood sample. If agglutination occurs, the blood contains B antigens. 3. Anti-Rh antibodies: Added to the blood sample. If agglutination occurs, the blood is Rh-positive.  Activity Time! Students are divided into 3 groups: Group 1- Students of this group will understand blood typing through interactive, using the link https://www.humanbiomedia.org/blood-typing-lab-simulation/ https://www.humanbiomedia.org/blood-typing-lab-simulation/ below. Based on the observation, they must answer the questions in the notebook. Group 2- Students of group 2 will use the simulation below to understand blood typing https://educationalgames.nobelprize.org/educational/medicine/bloodtypinggame/ https://educationalgames.nobelprize.org/educational/medicine/bloodtypinggame/ done for an accident victim. Students of group 2 to note down their observations in the notebook. Group 3- students of group 3 will identify blood of different individuals and understand blood https://www.sciencefromscientists.org/game/bloodtype.html https://www.sciencefromscientists.org/game/bloodtype.html typing using the virtual lab. Observation and conclusion to be written in the notebook.  ABO Can Can Blood ANTIGENS ANTIBODIES DONATE RECEIVE Type blood To: blood from: O+ O- A+ A- B+ B- AB + AB -  ABO Can Can Blood ANTIGENS ANTIBODIES DONATE RECEIVE Type blood To: blood from: O+ No A /B antigen but has Rh factor Anti A, Anti B O+, A+, B+, AB+ O+, O- O- No A /B antigen or Rh factor Anti A, Anti B Universal donor O- A+ has antigen A and Rh factor Anti B A+, AB+ A+, A-, O+, O- A- has antigen A and no Rh factor Anti B A-, A+, AB-, AB+ A-, O- B+ has antigen B and Rh factor Anti A B+, AB+ B+, B-, O+, O- B- has antigen B and no Rh factor Anti A B-, B+, AB-, AB+ B-, O- AB + Has antigen A and B and Rh factor - AB+ Universal recipient AB - Has antigen A and B but no Rh factor - AB -, AB+ A-, B-, O-, AB - BLOOD GROUPING LAB  Blood Transfusions A blood transfusion is a procedure in which blood is given to a patient through an intravenous (IV) line in one of the blood vessels. Blood transfusions are done to replace blood lost during surgery or a serious injury. A transfusion also may be done if a person’s body can't make blood properly because of an illness. Who can give you blood? Universal Donor People with TYPE O blood are called Universal Donors, because they can give O blood to any blood type. People with TYPE AB blood are called Universal Recipients, because they can A B receive any blood type. Rh + → Can receive + or - Rh - → Can only receive - AB Universal Recipient  Circulation Your body resembles a large roadmap, There are routes or “arteries” that take you downtown to the “heart” of the city. 3 Major Parts of the Circulatory system Blood Vessels - routes blood travels Heart – pumps or pushes blood through body Blood – carries important “ *stuff ” through body * Stuff – includes oxygen, food, & waste # 1 Blood Vessels : One Way Streets Blood Vessels resemble very long and skinny tunnels that are all through your body.  3 Types of Blood Vessels Arteries Capillaries Veins Arteries Capillaries Veins ARTERIES Carry blood away from the heart. The blood in the arteries is under high pressure and so: Arteries have thick outer walls, smaller lumen. Arteries have thick layers of muscles, elastic fibres, fibrous tissue VEINS Carry blood to the heart. The blood in the veins is under low pressure and so: Veins have thin walls, wide lumen Veins have mainly fibrous tissue, thin layers of muscle and elastic tissue. Capillaries Supply all cells of the body(Body parts) with their requirements, take away waste products Most of the blood pressure is lost so: Very thin wall, narrow lumen (Only one cell can pass through) Diffusion of materials between capillaries and body tissues easy.  Unlike arteries and capillaries, veins have one-way valves in them to keep the blood moving in the correct direction. Oxygenated blood - Blood that contains oxygen Mainly found in arteries Deoxygenated blood - Blood that does not contain oxygen Mainly found in veins  HOTS Why is there a need of capillaries? Are arteries and veins not sufficient to do the job? Why are there valves present in one type of blood vessel and not in the other? Why does the size of the lumen vary?  Action Time! Students research to examine the impact of lifestyle choices on the health of blood vessels and the potential consequences of vascular diseases. Think about it…. Why do we need valves? Why is there compartmentalization in heart? How do lungs, heart and body communicate? Is heart an organ or a tissue? How is obesity dangerous to the heart? What steps can you take to keep a healthy heart? Do heart and brain communicate? Yes or no, justify. How does compartmentalization help in working of organization?  STRUCTURE OF THE HUMAN HEART Schematic representation of the HUMAN HEART and the flow of blood through it.  CO2 LUNGS O2 exhaled inhaled Pulmonary Artery Pulmonary vein Vena Cava Aorta Pulmonary valve Aortic valve RIGHT ATRIUM LEFT ATRIUM Tricuspid valve Bicuspid or Mitral valve RIGHT VENTRICLE LEFT VENTRICLE TISSUES CO2 released O2 absorbed  CO2 LUNGS O2 exhaled inhaled Pulmonary Artery Pulmonary vein Vena Cava Aorta Pulmonary valve Aortic valve RIGHT ATRIUM LEFT ATRIUM Tricuspid valve Bicuspid or Mitral valve RIGHT VENTRICLE LEFT VENTRICLE TISSUES CO2 released O2 absorbed https://www.liveworkshe ets.com/w/en/pe/296878 Labelling Worksheet https://www.liv eworksheets.c om/w/en/pe/2 96878 Task 1: Label the parts of the human heart. Task 2: Trace the path of blood through the heart, as it passes through different compartments.  The heart is a muscular organ composed of cardiac muscle. It is divided into four chambers. These chambers include the top two, known as the atria (singular: atrium), and the bottom two, called ventricles.  The right atrium and right ventricle are responsible for receiving deoxygenated blood from the body. In contrast, the left atrium and left ventricle handle oxygenated blood from the lungs.  The vena cava are veins that return deoxygenated blood from the body to the right atrium of the heart. The pulmonary arteries transport deoxygenated blood from the heart to the lungs for oxygenation. This is an exception, as most arteries carry oxygenated blood.  The pulmonary veins carry oxygenated blood from the lungs to the left atrium. This is an exception, as most veins carry deoxygenated blood. The aorta, the body's largest artery, distributes oxygenated blood from the left ventricle to all parts of the body. Valves Atrioventricular valves and semilunar valves Backward flow of blood in the heart is stopped by 4 sets of valves. Atrio-ventricular valves separates each atrium from ventricles below it. Between right atrium and right ventricle is tricuspid valve (3 flaps). Between the left atrium and left ventricle is bicuspid valve (2 flaps). semi-lunar valves are present in the pulmonary artery as pulmonary valve and in the aorta as aortic valve.  The muscular walls of the Atria and Ventricles The septum is a wall of tissue separating the heart's right and left sides in such a way that it forms a barrier between the heart chambers. This prevents mixing of oxygenated and deoxygenated blood. The atria have much thinner walls than the ventricles. Why do you think that is ?  The muscular walls of the Atria and Ventricles The atria only must push the blood down to the ventricles, whereas the ventricles must push the blood out of the heart either to the lungs or the rest of the body. When comparing the walls of the ventricles the left ventricle has a wall is 3 times thicker than the wall of the right ventricle. Why do you think that is ?  The muscular walls of the Atria and Ventricles This is because even though the left and right ventricle pump same amount of blood, right ventricle only needs to create enough pressure to pump the blood to one organ i.e., lungs, which is situated next to the heart. Whereas the left ventricle must pump blood to all the major organs of the body.  Functioning of heart in terms of muscle contraction Functioning of heart in terms of muscle contraction Atrial Filling Both atria and ventricles are relaxed. Blood flows passively into the atria from the pulmonary veins (left side) and the vena cava (right side). The bicuspid (left) and tricuspid (right) valves are open, allowing blood to flow from the atria into the ventricles. Atrial contraction The atria contract, forcing the remaining blood into the ventricles. This ensures the ventricles are filled with blood before contraction. Functioning of heart in terms of muscle contraction Ventricular Contraction: The ventricles contract, increasing pressure. This pressure closes the bicuspid and tricuspid valves, preventing blood from flowing back into the atria. As ventricular pressure rises and the semilunar valves open. Blood is expelled from the ventricles into the aorta and pulmonary artery. Ventricular Relaxation: The ventricles relax, reducing pressure. The semilunar valves close, preventing the backflow of blood from the arteries.  Case Study A 10-Year-Old with a Ventricular Septal Defect (VSD) A 10-year-old child has been experiencing fatigue, difficulty breathing, and poor growth compared to peers. The child is often short of breath during physical activities, has a rapid heartbeat, and experiences frequent respiratory infections. After visiting a cardiologist, the child is diagnosed with a ventricular septal defect (VSD), a hole in the septum that separates the left and right ventricles of the heart. This condition allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood in the right ventricle, causing the heart to work harder to pump enough oxygen to the body.  Think – Pair - Share 1. What do you think is happening inside the heart due to the septal defect? 2. How might this defect explain the symptoms of fatigue, difficulty breathing, and poor growth? 3. What challenges do you think the heart faces in maintaining proper circulation with this defect?  Reflect How does understanding the structure and function of the heart help us in diagnosing and treating heart conditions? Double Circulation  PULMONARY CIRCUIT The blood is pumped to the lungs & returns to the heart SYSTEMIC CIRCUIT The blood is pumped to respiring muscles & back to the heart again 1. Deoxygenated 2. The blood receives blood is pumped from oxygen and is pumped the heart to the lungs back to the heart 4. The oxygen leaves the blood 3. The oxygenated blood to be used for respiration in the is then pumped to the body and the blood goes back rest of the body to the heart Evolution Snapshot of the Heart 1. Identify how many chambers each type of heart has. 2. What are the consequences of mixing of oxygenated and deoxygenated blood in these hearts ? 1. Why do you think mammals and birds have evolved to have four-chambered hearts? 2. What challenges might reptiles face with their three-chambered heart that birds and mammals avoid with their four chambers?  Coronary arteries The heart muscles needs a constant supply of oxygen and nutrients so that it can keep contracting and relaxing. The coronary arteries are the blood vessels that supply this to all the muscles of the heart. Coronary heart disease -ROBOT CLASS Coronary arteries, which supply oxygen-rich blood to the heart muscle, become narrowed or blocked due to the buildup of fatty deposits called plaques. This process, known as atherosclerosis. This can reduce blood flow to the heart, leading to symptoms like chest pain (angina) or, in severe cases, a heart attack.  Coronary heart disease Research activity Work in groups to outline the following for coronary heart disease (at least 3 points for each) Causes Geographical prevalence Symptoms Diagnosis Treatment and management Prevention Investigation on the effect of physical activity on heart rate Teacher divides the class into 5 groups. Each group is asked to have: a student assigned whose pulse would be checked, a student who would check the pulse, a student who would time the process, a student who would note down the data and a student who would monitor that the process is performed properly. After the groups are ready - students check the pulse of the volunteer in the resting position and note down the observation. They then ask the student to walk and jog at their place for 5 min. in the same place and note down the observations (observations need to be noted in table). Graph plotting - students are asked to plot a graph on the same GUIDING QUESTIONS Why is there a difference in heart rate at rest and post exercise? How are heart rate and breathing rate related? Critical thinking: What is ECG? And what is its significance? How do breathing disorders affect heart rate and how do heart disorders affect breathing? Define the following… PULSE HEART BEAT HEART RATE Heart rate: The number of times the heart beats per minute (bpm). Heartbeat: A single cycle of the heart as it contracts (pumps blood) and relaxes. Pulse: The rhythmic throbbing of arteries caused by the beating of the heart, usually felt at points like the wrist. Every heartbeat has two phases Systole: The phase of the heartbeat when the Systole heart muscle contracts and pumps blood out of the chambers. Diastole: The phase of the heartbeat when the heart muscle relaxes, and the chambers fill with blood. Diastole  Blood pressure Blood pressure is the measure of the force of blood pushing against blood vessel wall. The heart pumps blood into the arteries (blood vessels), which carry the blood throughout the body.  Blood pressure Blood pressure is recorded as two numbers systolic pressure (as the heartbeats) diastolic pressure (as the heart relaxes between beats).  Blood pressure These measurement is written one above or before the other, with the systolic number on top and the diastolic number on the bottom. For example, a blood pressure measurement of 120/80 mmHg (millimeters of mercury) It expressed verbally as "120 over 80." Apparatus used to measure Blood pressure Sphygmomanometer Normal blood pressure : Less than 120 over 80 (120/80) Hypertension and hypotension are conditions related to blood pressure but represent opposite ends of the spectrum. While hypertension is a condition of persistently high blood pressure, hypotension refers to unusually low blood pressure. Both conditions have different causes, symptoms, and treatment options. Pre-hypertension: 120-139 over 80-89 Stage 1 high blood pressure: 140-159 over 90-99 Stage 2 high blood pressure: 160 and above over 100 and above People whose blood pressure is above the normal range should consult their doctor about steps to take to lower it. Links related to Blood pressure. http://watchlearnlive.heart.org/CVML_Player.php?moduleSelect=hig hbp http://www.youtube.com/watch?v=oioFVbsiwEk https://www.youtube.com/watch?v=qWti31 7qb_w  https://www.youtube.com/watch?v=co 6iuDpaQTM- what is blood https://www.youtube.com/watch?v=no MsCGRkwSE - blood https://www.youtube.com/watch?v=QS PfQTDcw34 – valves https://www.youtube.com/watch?v=_e Videos VG45_iF9U&t=2s – how your heart works related to https://www.youtube.com/watch?v=l44 oNfxmIns - human blood the topic http://www.redcrossblood.org/donatin g-blood/donor-zone/games/blood-type - blood type game https://www.nobelprize.org/educationa l/medicine/landsteiner/readmore.html - about blood LYMPHATIC SYSTEM  The lymphatic system can be called as a subsystem of the circulatory system. It acts as a drainage system that returns excess fluid to the bloodstream This is to maintain fluid balance and lymphatic system also plays a key role in blood filtration and immunity. It consists of a complex network of lymphatic vessels, tissues, and organs.  Lymphatic System Structure and Function ❑ Consists of: 1. Lymph 2. Lymphatic vessels 3. Structures and organs containing lymphatic tissue 4. Red bone marrow ❑ Functions of the lymphatic system 1. Drains excess interstitial fluid. 2. Transports dietary lipid/fats from intestines to blood. The lipid-containing lymph is called Chyle. 3. Carry out immune responses. Fig.1: Components of the lymphatic system. 130  Interstitial fluid is the fluid that surrounds the cells in tissues. It is derived from blood plasma that leaks out of capillaries to deliver nutrients and remove waste. When interstitial fluid doesn’t return directly to the blood, the lymphatic system collects it, like excess rainwater being collected by drainage pipes. Now this fluid is called the lymph. Lymph is a clear, watery fluid that contains mostly water, certain proteins and white blood cells Robot lesson Lymphatic system  https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSzVli16wJfKKcS_rcdY5iTDXSsgAyKH9zkP6CRxW5TLA2zgQ Lymphatic Vessels ❑ Vessels begin as lymphatic capillaries. ❑ These are closed at one end. ❑ Lymphatic capillaries unite to form large lymphatic vessels. ❑ These resemble veins in structure but thinner walls and more valves. ❑ They pump the lymph fluid with the help of skeletal and smooth muscles. Fig.3: The distribution of lymphatic ❑ To prevent the backflow the larger lymph vessels are present with vessels in the body showing the valves. lymph nodes. Also shown is the closed end of a lymphatic capillary. 134  https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSzVli16wJfKKcS_rcdY5iTDXSsgAyKH9zkP6CRxW5TLA Lymph nodes ❑ Lymph nodes are a series of swellings present along the lymphatic vessels. ❑ They are located at regular intervals in the Lymphatic System. ❑ It is a mere collection of lymphoid tissue. ❑ Lymphoid tissue is composed of lymphocytes along with other specialized cells and tissues ❑ Help in maintaining the immune system’s functions. Fig.3: The distribution of lymphatic vessels in the body showing the lymph nodes. Also shown is the closed end of a lymphatic capillary. 135  https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcR7VRNOsoWpH-FbNmDe_wdJqDVe1xO6G9nZbLQb4tFUjU1 Ultimately, the lymph drains into 2 main channels: 1. Thoracic duct: a long duct that drains lymph from the entire left half of the body and the right half below the ribs including the right lower limb. 2. Right lymphatic duct: a short duct that drains lymph from the right side of the body above the ribs including the right upper limb. Fig.4: Areas of lymph drainage to the two main lymphatic ducts.136 ❑ Each of these ducts open into the junction of the subclavian and internal jugular veins as they form the brachiocephalic vein. ❑ In this way, the lymph will return to the blood. Fig.5: Opening of the lymphatic ducts into the venous circulation. 137  3D Simulation https://www.lls.org/3d-model-library/lymph-node-anatomy-3d- model  Lymphatic Circulation ▪ The Lymphatic System can be thought of as a drainage system that is needed by the body because blood circulates, and its plasma is leaked into the thin walls of the capillaries. ▪ Interstitial fluid is the portion of the blood plasma that escapes, and it contains oxygen, amino acid, and other useful nutrients that are needed by the body and tissue cells. ▪ Almost all of the fluid gets back into the bloodstream but a small percentage of it along with the particulate matter is left behind. ▪ The Lymphatic System helps in removing these fluids and materials from tissues, preventing the fluid imbalance in the body. This imbalance can lead to the death of the organism.  Lymphatic Circulation ▪ This lymph gets drained into larger vessels that are known as lymphatic vessels. ▪ These lymphatic vessels are punctuated at intervals by small masses of lymph tissue which are known as lymph nodes. ▪ these vessels converge to form the lymphatic trunk. ▪ These lymphatic trunks drain into the veins. ▪ Thus, the excess materials or the infectious microorganisms are removed via this pathway.  Written Task Toddle - Test ID WT01_Lymphatic system Draw or design a flowchart to show lymph flow in the body. Your flowchart must include the following 1. Origin of lymph 2. Transport of lymph 3. The ultimate fate of lymph (where it ends up) Lymphocytes Lymphocytes are a type of white blood cell that plays a key role in the body’s immune system. Their main job is to protect the body from harmful invaders like viruses, bacteria, and other germs. There are two main types of lymphocytes: B lymphocytes (B cells): produce proteins called antibodies that attach to harmful invaders, like bacteria or viruses, and help destroy them. T lymphocytes (T cells): “soldiers” of the immune system that go out and directly fight against germs.  Lymphoid Organs The body lymph system is divided into primary lymphoid organs and secondary lymphoid organs. Primary Lymphoid Organs Site for the production and maturation of lymphocytes. Humans have two primary lymphatic organs – the thymus gland red bone marrow B and T cells are formed in the bone marrow B cells mature in the bone marrow while T cells mature once they migrate to the thymus.  Secondary Lymphoid Organs These are the sites where lymphocytes become activated. Once B and T cells have matured, they travel through the bloodstream to these secondary lymphoid organs. Here, they encounter foreign substances, known as antigens, which trigger their activation. This is where the mature lymphocytes carry out their immune functions. Examples of secondary lymphoid organs include lymph nodes, the spleen, and tonsils.  Role Play Instruct students to research Divide the class into four and discuss the information groups, assigning each group together, focusing on displaying one of the lymphatic organs: the structure, location, spleen, thymus, lymph node function, and importance of and tonsils their assigned lymphatic organ Groups to take turns sharing Encourage discussion and what they learned about their collaboration as students assigned lymphatic organ with compare and contrast the the class in the form of a role functions of the different play. lymphatic organs Lymphatic organs Thymus Gland Located inside the ribcage, just behind the breastbone. Produces hormones that support the development, maturation, and differentiation of T cells (a type of white blood cell). Tonsils Small, rounded masses at the back of the throat, near the base of the tongue. Produce lymphocytes and antibodies that fight infections. Act as a first line of defense by trapping inhaled or ingested pathogens. Spleen Soft and spongy organ located on the left side of the abdomen, just under the diaphragm. Produces white blood cells, filters blood by removing bacteria, damaged red blood cells, and platelets. Lymphatic organs Bone Marrow Spongy tissue found within bones. Produces blood cells, including B lymphocytes Lymph Nodes Small, bean-shaped clusters of lymphatic tissue. Found along lymphatic vessels; concentrated in the neck. Filter lymph fluid, trap germs, and activate antibodies to fight infections.  Written Task Toddle - Test ID WT02_Lymphatic system Robot lesson Organs of the Lymphatic system  Defense against diseases THE IMMUNE SYSTEM Micro-organisms Etymology of the term Micro- very small. Organism- a living thing. Examples: Bacteria, fungi, protozoa, algae. They may be single / multicellular. What are pathogens? They are disease causing micro-organisms. When is a micro-organism considered as a pathogen to a particular disease? Koch’s Postulates : 1. A specific organism can always be found in association with a given disease. 2. The organism can be isolated and grown in pure culture a laboratory. 3. This cultured pathogen grown in lab will produce the same disease when inoculated into a susceptible, healthy host. 4. It is possible to recover/re-isolate the same organism from the experimentally infected host. Limitation - Viruses, unlike many bacteria, require living cells to replicate and cannot be grown in pure culture outside of a host, which makes it impossible for them to meet the second postulate.  Written Task Toddle - Test ID WT03_Koch's postulates  Microorganisms: The good side Decompose organic waste. Are producers in the ecosystem via photosynthesis. Produce industrial chemicals such as ethyl alcohol and acetone. Produce fermented foods such as vinegar, cheese, curd and bread. Production of antibiotics, vaccines. Increasing soil fertility. Cleaning the environment.  Living things are broadly categorized into two groups Prokaryotes Eukaryotes From Old Greek pro- before, karyon - Greek ευ, meaning good/true, and referring to the cell nucleus. karyon - referring to the nucleus. Organisms without a cell nucleus (= Organisms whose cells are organized karyon), or any other membrane- into complex structures by internal bound organelles. membranes. Most are unicellular. Animals, plants, fungi, and protists are eukaryotes.  1. Bacteria Bacteria are Prokaryotes because their genetic material (DNA) is not housed within a true nucleus. Found in nearly every habitat on earth, including within and on humans. Most bacteria are harmless or helpful, but some are pathogens, causing disease in humans and other animals.  1. Bacteria Bacteria are often described in terms of their general shape. Common shapes include spherical (coccus), rod-shaped (bacillus), or curved (spirillum, spirochete, or vibrio). They divide and reproduce by binary fission. Bacteria can be killed with antibiotics because these substances target key processes in bacteria, such as production of the bacterial cell wall. Bacteria divide and double in number every 20 minutes !!!  Bad bacteria in the mouth cause teeth to rot. Mouth bacteria Mouth bacterium  2. Viruses Viruses are extremely small (much smaller than bacteria) acellular microorganisms, which means they are not composed of cells. Essentially, a virus consists of proteins and genetic material—either DNA or RNA, but never both. NON-LIVING microbes that need a host cell so that they can reproduce and survive.  2. Viruses Viruses can infect all types of cells, from human cells to the cells of other microorganisms. Colds and influenza are caused by viruses. Antibiotics cannot kill viruses because viruses have different structures and replicate in a different way than bacteria. Antiviral drugs are used to treat viral infections. Structure of viruses A T4 bacteriophage. This infects only bacterial cells, in this case only E. coli Measles virus Electron microscope picture of the measles virus Boy with measles 3. Fungi Fungi are eukaryotic, non-motile and heterotrophic organisms. Do not photosynthesize but feed by saprophytic (on dead or decaying material) or parasitic (on live material) nutrition. They include both microscopic (yeast) and macroscopic (mushrooms) organisms. Fungi come in the form of moulds, yeasts, mushrooms.  3. Fungi Most fungi are filamentous structures. They have long thread-like hyphae, which form a network called mycelium. They have a vital role in the ecosystem as decomposers. Spores help in the reproduction of fungi. Uses - 1. Recycling – recycling the dead and decayed matter. 2. Food – The mushrooms species that are edible are used as food by humans. 3. Medicines – There are many fungi that are used to produce antibiotics and to control diseases in humans and animals. 1. Eg: Penicillin antibiotic is derived from a common fungus called Penicillium. 4. Biocontrol Agents – Fungi are involved in controlling the population of pests such as insects, other small worms. 5. Food spoilage –responsible for major spoilage and economic losses of stored food.  Examples of fungi There can be good forms of fungus (used to make bread/beer) bad forms of fungus (Mold, Athletes foot and thrush). Robot lesson Fungi  Protozoa Protozoa are unicellular, eukaryotic, heterotrophic organisms. They are either free-living or parasites. They survive by absorbing or ingest organic matter. May be motile(can move) via structures like pseudopods, cilia, or flagella. They lack a rigid cell wall, so they are flexible and found in various shapes.  Amoebiasis Entamoeba histolytica Malaria Plasmodium falciparum, P. vivax, P. malariae, P. ovale Link !! http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel/heal th/defendingagainstinfectionrev1.shtml Additional Information on Microbes  Task Human disease Causative Mode of Preventive microorganism transmission measures Malaria Measle Chicken pox Small pox Typhoid Polio Hepatitis B Tuberculosis Cholera  Transmissible disease A contagious disease wherein the pathogen is transmissible from one host to another. A transmissible disease may be transmitted through direct contact (e.g. blood exchange with an infected host) or through a vector (e.g. contaminated surfaces, formite, air, foods, animals, etc.).  How do infections spread? Direct contact infections spread when disease-causing microorganisms pass from the infected person to the healthy person via direct physical contact with blood or body fluids. Examples of direct contact are touching, kissing, sexual contact, contact with oral secretions, or contact with body lesions. Indirect contact infections occurs when there is no direct human-to-human contact. Contact occurs from a reservoir to contaminated surfaces or objects, or to vectors such as mosquitoes, flies, mites, fleas, ticks, rodents or dogs. Spread when an infected person sneezes or coughs, sending infectious droplets into the air. If healthy people inhale the infectious droplets, or if the contaminated droplets land directly in their eyes, nose or mouth, they risk becoming ill. Droplets generally travel between three and six feet and land on surfaces or objects including tables, doorknobs and telephones. Healthy people touch the contaminated objects with their hands, and then touch their eyes, nose or mouth. OUR IMMUNE SYSTEM Lines of Defense First line of Defense Second line of Defense Third line of Defense Non-Specific surface barriers Non-Specific innate immunity Specific adaptive immunity Physical Barriers Skin Phagocytosis Lymphocytes Mucous membranes Inflammatory Response Antibodies Hair and cilia Fever Memory Cells Chemical barriers Natural Killer (NK) Cells Stomach Acid Tears and Saliva Sweat and Oils First Line of Defense: Physical and Chemical Barriers These are non-specific defenses that aim to prevent pathogens from entering the body in the first place. They act as external barriers and are often referred to as innate defenses. PHYSICAL BARRIERS: Skin: Acts as a tough, physical shield against infection. Mucous Membranes: Line the respiratory, digestive, and urogenital tracts and trap pathogens. Hair and Cilia: Nose hairs and cilia in the respiratory tract trap dust and pathogens, moving them out of the body.  Mucous membranes Skin and cilia CHEMICAL BARRIERS Stomach Acid: Kills most ingested pathogens due to its low pH. Tears and Saliva: Contain enzymes (like lysozyme) that can break down bacterial cell walls. Sweat and Oils: Create an acidic environment on the skin that discourages pathogen growth. Stomach Tears and Sweat and acids saliva sebum Second Line of Defense: Innate Immune Response If a pathogen bypasses the first line of defense, the innate immune system provides a rapid, non-specific response to try and eliminate it. Second line of Defense Non-Specific innate immunity Phagocytosis Inflammatory Response Fever Natural Killer (NK) Cells  Role of White Blood Cells (WBCs) White blood cells, including phagocytes and lymphocytes, are essential to immune defense. They recognize and attack pathogens, either by directly killing them or by marking them for destruction.  White blood cells Phagocytes Lymphocytes Second Line of Defense Neutrophils Macrophages Natural killer cells B Lymphocyte T Lymphocytes Third Line of Defense Phagocytosis Phagocytosis is the process by which certain immune cells engulf and digest foreign particles, bacteria, and dead or dying cells. Phagocytes: Neutrophils and Macrophages. The phagocyte surrounds the pathogen, engulfs it into a vesicle, and then uses enzymes to break it down. Natural Killer (NK) Cells: Attack and destroy infected or abnormal cells in the body, such as virus-infected cells or cancer cells. virus-infected cells  Inflammatory Response Fever Inflammation occurs when tissues are Raises body temperature to create injured or infected, causing blood flow an inhospitable environment for to increase to the area, allowing more pathogens and enhance immune cell immune cells to reach the site of activity. infection. Third Line of Defense Adaptive (Acquired) Immune Response The adaptive immune system is specific, meaning it targets particular pathogens. This line of defense also has memory capabilities, which allow it to respond more effectively to pathogens it has encountered before. Third line of Defense Specific adaptive immunity Lymphocytes Antibodies Memory Cells  LYMPHOCYTES B Cells Produce antibodies that specifically target and neutralize pathogens or mark them for destruction by other immune cells.  Antibodies Produced by B cells, antibodies specifically bind to antigens (foreign molecules on pathogens) and mark them for destruction or neutralize them.  LYMPHOCYTES T Cells Recognize infected cells and destroy them directly or help coordinate the immune response. Memory Cells: After an infection, some B and T cells become memory B and T cells and remain in the body. They are ready to respond more rapidly if the same pathogen attacks again. B cells sense B cells produces Once the infection pathogens antibodies cleared, some B cells turn into memory cells.  Active and passive immunity Active Immunity: Passive Immunity: The body’s own immune system produces Immunity obtained through antibodies antibodies and memory cells in response produced by another person or animal. to exposure to a pathogen or a vaccine. This can occur naturally (e.g., maternal This type of immunity is long-lasting and antibodies transferred to a newborn) or can be permanent. artificially (e.g., antibody injections). Passive immunity is temporary, as it does not involve the immune system actively responding to pathogens. Vaccines and how they work  Extra notes on IMMUNE SYSTEM Slides 216 to 254