Chapter 13 and 14 Life Science Ms. Hanlin Diseases and Immunity Chapter 13 and 14 Life Science Ms. Hanlin

Discovering diseases With the invention of the microscope, bacteria, yeast and mold were seen for the first time at the end of the 17th century. However, scientists did not make a connection between these small organisms and diseases until the late 1800’s and early 1900’s Louis Pasteur was the first to say that microorganisms cause disease in humans. Found that these small organisms could spoil milk and attack the human body in a similar way Pasteurization- process of heating a liquid to kill bacteria

Agents of disease Bacteria: tuberculosis, strep throat, plague, pneumonia, tetanus Protists: malaria, sleeping sickness Fungi: athletes foot, ringworm Viruses: cold, influenza, AIDS, measles, mumps, polio, smallpox, Ebola

Infectious Diseases The conditions of your body, such as temperature and nutrients, help harmful bacteria or viruses get into your body, multiply, and grow. A disease that is caused from a virus, bacteria, protist, or fungi and is spread from one organism to another, is called an infectious disease. Can be spread through the air, food, contact, or biological vectors .

Vectors Vectors for diseases can be rats, birds, cats, dogs, mosquitoes, fleas, flies, etc. People can also be vectors or carriers of the disease. When people with a disease come in contact with other people, they can spread a disease, even if they are immune to it.

Chronic Diseases Not all diseases are caused by pathogens. Diseases and disorders like allergies, diabetes, cancer, and heat disease are noninfectious diseases. They can not be spread from one person to another. They are “chronic”, meaning they last a long time Some infectious disease can be chronic as well AIDS

Cancer Cancer is the name given to a group of diseases characterized by uncontrolled cell growth. Tumors from increases cell division can occur anywhere and can spread through your blood stream. 1940’s and 1950’s: recognized genes related to cancer. Carcinogens: increase risk of cancer chemicals, smoking, alcohol, types of home and garden chemical, X rays, radiation, sun, etc.

Diabetes A chronic disease associated with levels of insulin produced by the pancreas. Insulin helps the sugar in your blood get into the cells to make energy. Two types of Diabetes: Type 1: too little or no insulin production Type 2: body produces insulin but does not properly use it.

Allergies An allergy is an overly strong reaction of your immune system. Most are minor, but more severe reactions can lead to hospitalization or death. Allergens lead to an allergic reaction. When you come in contact with an allergen, your immune system forms antibodies. Your body responds with histamines (inflammation), leading to red, swollen tissues. Antihistamines treat allergies by reducing inflammation. Asthma: antihistamine decreases swollen lung tissues

Active immunity vs. Passive Immunity When you get sick from a disease, your body recognizes the diseases using antibodies (made by the B cells) Memory B cells remember the disease and are ready to fight if you get it again. Antibodies help your body in two ways, actively and passively. Active: body makes its own antibodies Passive: Antibodies produced by another organism (your mother) are introduced to your body.

Blood Typing Blood cells have proteins on the outside of their cell membranes. Your immune system recognizes these cells as “self” and does not attack. Any blood cells that do not have this familiar marker, the white blood cells with think it is a foreign invader and will attack (much like when you get a virus in your cells) This is why we have different blood types.

Blood Typing System There are two main types of blood typing, the ABO system and the Rh system Each person has a combination of these two groups (AB positive) In the ABO system, there are 4 groups A B AB O In the Rh system there are two groups Rh positive Rh negative

Blood Typing Cont. A person with type A blood can recognize the A blood cells and will not destroy it, however, if given type B blood, it will destroy those cells. AB individuals can recognize both markers Individuals with O blood do not have any of the ABO markers. No signal for immune cells to attack.

Homework Finish the worksheet provided by filling in the chart and answering the questions. This will be due tomorrow. Tomorrow: Blood Typing Lab Wednesday: Science Fair Work Day/Movie Thursday: Notes over Blood Next Week: Components of Blood Lab