Learning outcomes.. At the end of lesson, you should be able to: Describe the formation interstitial fluid State the composition of interstitial fluid State the importance of interstitial fluid Describe the fate of interstitial fluid Describe the structure of the lymphatic system Explain how the lymphatic system complements the circulatory system Compare the content of blood, interstitial fluid and lymph Predict what will happen if interstitial fluid fails to return to the circulatory system Conceptualize the relationship between the lymphatic system and circulatory system
Lymphatic system The three parts of the lymphatic system are: The lymph vessels The lymph nodes The lymph fluid The functions of the system are: Maintains fluid balance within our tissues Transports fat (an important nutrient) absorbed from the intestine to the bloodstream Is a vital part of the immune system as it removes microorganisms and other disease-causing substances from body tissues.
Lymph vessels begin as small closed end tubes found in the spaces between cells within tissue. After the tissue fluid enters the lymph capillaries (the smallest vessels) it is referred to as fluid. Lymph capillaries merge to form larger lymph
Drainage area.. Right drainage area Left drainage area
Drainage area.. Right drainage area Left drainage area Drains lymph from the right Drains lymph from the left side side of the head and neck of the head and neck The right arm The Left arm and the left upper Upper right quadrant of the quadrant body. The lower trunk and both legs Lymph from this area flows into the right lymphatic The cisterna chyli temporarily duct. stores lymph as it moves This duct empties the upward from the lower areas of lymph into the right the body. subclavian vein. The thoracic duct transports lymph upward to the left lymphatic duct. The left lymphatic duct empties
What is going to happen to thelymph fluid? Back to the blood to become plasma again.
Arterial end of capillaries• High pressure forces water & dissolved substances out into the interstitial spaces• The fluid is called interstitial fluid. Venous end of capillary• Blood absorbs 90% ISF• 10% of ISF passes back into blood circulatory system as lymph via the lymphatic system.
Composition of interstitial fluid(ISF) Similar in composition in blood plasma Do not have erythrocytes, platelet and large protein molecules. Consists of a water solvent containing amino acids, sugars, fatty acids, coenzymes, hormones, neurotransmitter s, salts, as well as waste products from the cells.
Importance of interstitial fluid(ISF) It forms the internal environment of the body. Bathes the cells and supplies them with oxygen and nutrients. Waste products such as CO2 and urea diffuse out from the cells into interstitial fluid. Keep the body within normal range range homeostatic process.
How the lymphatic systemcomplements the circulatorysystem Lymph travels through the lymphatic vessels by the contraction on the surrounding skeletal muscles. Lymph flow in one direction. One end of the vessel is closed and back flow is prevented by valves present in the larger vessels. Smaller lymphatic vessels join to form larger vessels. The vessels from the left side of the body, the alimentary canal and the right side of the lower
Cont. It carries lymph to the left subclavian vein and back to the bloodstream. Right lymphatic duct transport lymphs from the right side of the head and chest into the right subclavian vein.
Role of Lymphatic System inTransport1. Collects the ISF and returns it back to the circulatory system2. Lacteals: lymphatic capillaries in the villi of the illeum Absorbs fat and fat-soluble vitamins and transport them to the blood circulatory system3. Lymph nodes: Filter out bacteria and foreign particles (by phagocytes)4. Lymphocytes in the lymphatic tissues: Produce antibodies (aid destruction of pathogens and the neutralization of toxins)
Comparison of the Cardiovascular and Lymphatic Systems Cardiovascular System Lymphatic System (Blood) (Lymph)Blood is responsible for collecting and Lymph is responsible for collecting anddistributing oxygen, nutrients and removing waste products left behind inhormones to the tissues of entire body. the tissues.Blood flows in a closed continuous loop Lymph flows in an open circuit from thethroughout the body via the arteries, tissues into lymphatic vessels. Oncecapillaries, and veins. within these vessels, lymph flows in only one direction.Blood is pumped. The heart pumps Lymph is not pumped. It passivelyblood into the arteries that carry it to all flows from the tissues into the lymphof the body. Veins return blood from all capillaries. Flow within the lymphaticparts of the body to the heart. vessels is aided by other body movements such as deep breathing and the action of nearby muscles and blood vessels.
Blood consists of the liquid Lymph that has been filtered andplasma that transports the red is ready to return to theand white blood cells and cardiovascular system is a clearplatelets. or milky white fluid.Blood is visible and damage to Lymph is invisible and damageblood vessels causes obvious to the lymphatic system issigns such as bleeding or difficult to detect until swellingbruising. occurs.Blood is filtered by the kidneys. Lymph is filtered by lymph nodesAll blood flows through the located throughout the body.kidneys where waste products These nodes remove some fluidand excess fluids are removed. and debris. They also killNecessary fluids are returned to pathogens and some cancerthe cardiovascular circulation. cells.Blood vessel damage or Lymphatic vessel damage orinsufficiency produces swelling insufficiency produces swellingthat containing low-protein fluid. containing protein-rich fluid.
Assignment 1.61. Compare the contents of blood and lymph. BLOOD SIMILARITIES LYMPH BLOOD DIFFERENCES LYMPH Glucose Protein molecules Oxygen Waste materials Erythrocytes Leucocytes Platelets
1.5Role of the circulatory system inthe body’s defence mechanisms
Learning outcomes.. At the end of lesson, you should be able to.. State another function of circulatory system besides transport Identify the three lines of defence mechanism of body Describe the process of phagocytosis State the meaning of antigen and antibody State the meaning of immunity and immunization Relate antigen and antibody to immunity Name and give examples of various Types of immunity State the effects of Human Immunodeficiency virus (HIV) on the body’s defence mechanism Describe the transmission of HIV Suggest ways to prevent the spread of Acquired Immune Deficiency Syndrome ( AIDS)
Body’s defence mechanism Human bodies have three lines of defence against pathogens. Firstline of defence (skin, mucous membrane) Second line of defence (phagocytes) Third line of defence (lymphocytes)
First line of defence Skin Acts as a physical barrier Made up of dead keratinized layer which is difficult to penetrate Sebaceous glands secrete sebum which contain lysozymes to destroy bacteria
First line of defence Mucous membranes Mucus in the nasal cavity trap dust particles and spores Cilia (respiratory tract) sweep the trapped particles to the pharynx. Gastric juices (in stomach) will killed microorganisms that enter the stomach.
Second line of defence If the pathogens are able to get past the first line of defence, for example, through a cut in your skin, and an infection develops, the second line of defence becomes active. Some WBC such as neutrophils act as phagocytes. They are attracted by the chemicals produced at the sites of infection. The phagocytes move towards the pathogens and engulf them by phagocytosis.
Third line of defence Lymphocytes are WBC found in the lymph nodes and in the blood circulatory system. Two types of lymphocytes: T-lymphocytes Attackcells infected by pathogens or Produce certain chemicals to coordinate immune response B-lymphocytes Produce antibodies
Cont. Antibody – protein produced by lymphocytes in response to the presence of an antigen. Antigen – foreign substance which stimulates the body to produce an immune response Antibodies are specific in action and promote the destruction of antigens in different ways.
After an infection, some lymphocytes remain in the body as memory cells. Memory lymphocytes help to defend the body against further infection by the same antigen.
Types of immunity Immunity: the ability of an organism to defend itself against infection by pathogens. Types of immunity: Activeimmunity (natural & artificial) Passive immunity (natural & artificial) Immunisation: the process by which an individuals immune system becomes fortified against an agent (known as the immunogen).
Types of immunity Immunity Active Own antibodies NaturalExposure to Artificial infectious Immunization agent
Acquired Passive Immunity Inherited natural immunity: inherited by individual through the placenta or mother’s milk.
Active natural immunity Active natural acquired immunity: acquired after a person recovers from an infection. Eg; measles or chickenpox.
Active artificial immunity Active artificial acquired immunity: Eg; vaccine (contains killed or weakened antigens). Active because the a/bodies produced by the body itself Artificial because it is obtained through vaccination. the process is known as immunisation.
Passive immunity1. Passive natural immunity: when a/bodies from the mother transported across the placenta to the foetus. Lasts for a few months.2. Passive artificial immunity: injecting serum containing a specific a/bodies prepared from human/animal’s blood.
Passive artificial immunity Usually used to treat patient with serious ill. Eg: rabies, tetanus or snake bites Give temporary immunity.
Human Immunodeficiency Virus(HIV)- Effects on the body’s defence mechanism AIDS (acquired immune deficiency syndrome) is caused by HIV. HIV infects the helper T-cells (important to activate other lymphocytes in the body’s defence mechanisms against disease). Once infected, it takes a long incubation period before the symptoms appear. A person’s immune system gradually decrease in function and tend to get infected by secondary infection such as pneumonia, meningitis and fungal diseases. He/she may develop a cancer. Eg: Kaposi’s
Transmission of HIVThere are several possible ways in which the virus can enter.1. Having sex with an infected partner2. Injection-drug users who share needles or syringes that are contaminated with blood from an infected person.3. Women can transmit HIV to their babies during pregnancy or birth, when infected maternal cells enter the babys circulation, or through breastfeeding.4. HIV can be spread in health-care settings through accidental needle sticks or contact with contaminated fluids.
Transmission of HIV5. Transfusion of contaminated blood or blood components.6. The virus does not spread through casual contact such as preparing food, sharing towels and bedding, or via swimming pools, telephones, or toilet seats. The virus is also unlikely to be spread by contact with saliva, unless it is contaminated with blood.
Ways to prevent the spread of AIDS Abstain from sex. Use a condom in other situations. Do not share needles or inject illicit drugs. If you work in a health-care field, follow recommended guidelines for protecting yourself against needle sticks and exposure to contaminated fluids. If you have engaged in risky behaviors, get tested to see if you have HIV. Strict screening of blood before transfusion. Awareness campaign and counseling.
Appreciating a healthycardiovascular system1.6
Learning outcomes.. At the end of lesson, you should be able to: Selectand practice suitable ways to maintain a healthy cardiovascular system.
Risk factors for cardiovasculardiseases (CVD)Cardiovascular diseases share risk factors withother major diseases. Tobacco smoking Poor diet and nutrition Physical inactivity Overweight and obesity High blood pressure High blood cholesterol Diabetes High alcohol consumption
How to take care of healthycardiovascular system? Follow a well-balanced diet that is low in saturated fats, cholesterol and salt. Maintain a healthy weight to reduce stress on the heart, blood vessels, and lymph vessels. Participate in regular aerobic exercise for at least 30 minutes three to four times per week. Avoid the use of tobacco products and exposure to secondhand tobacco smoke. Avoid illegal drugs including stimulants, marijuana and ecstasy.