Maintenance of Living Things

 Remember, to be “alive” you need to carry out the eight life processes! 1. Respiration 2. Regulation 3. Repair/ Growth 4. Reproduction 5.Transport 6. Excretion 7. Nutrition 8. Synthesis

 Is the internal stability, maintaining your body  Three main ways your body maintains homeostasis:  Temperature regulation  Waste disposal and water regulation  Hormones

 Defined as thermoregulation ( home thermostat)  Negative feedback- change in the condition triggers the response in the body  Example- when your body temperature rises above a set point- your brain will stimulate an activity to lower it  - Sweating: cools your body through evaporation

 Regulates the chemical makeup of body fluids- blood and interstitial fluid.  Removes waste products and balances intake and loss of water  Kidneys play a major role in excretion removing urea and regulate the water and salt balance

 Chemical messengers called hormones can triggers responses to maintain homeostasis  Hormones can regulate blood pressure, heart rate, digestion, water and salt balance  Hormones are secreted into the bloodstream and reach target cells- hormone will trigger the action within the cell

Pancreas

How does the immune system help to maintain homeostasis? Why do some people tend to get sick more often then others? How does your body respond to infection?

 Immunity- the ability to resist disease due to the presence of antibodies  Our immune system fights against:  Pathogens: an antigen that causes disease, infection

Pathogen Antibodies and Antigens

 Antigen- a large molecule which provokes an immune response  Antibodies- proteins found on the surface of WBC’s which attach to specific antigens. anything the body sees as foreign (bacteria, virus or harmless pollen) protein made by lymphocytes to attract phagocytes; alerts phagocytes to destroy antigen (like Paul Revere!)

 your body produces antibodies against the infection; usually permanent  Occurs when you come in contact with or get the disease  Or when you get a vaccine (a dose of a pathogen or part of the pathogen that has been disabled or destroyed so it is no longer harmful) How does this work???? -are made from the antigens of the pathogen. Your body is fooled into “thinking” it is fighting against the pathogen.

 Usually temporary; immunity given to you  Your body receives antibodies from another source.  Mother to Fetus during pregnancy; breast feeding  Injected with antibodies

 Occurs when certain “harmless (dust pollen, insect bites)” substances are seen as harmful antigens  A specific type of WBC called Mast Cells  produce antibodies which produce histamines (chemicals that cause sneezing, itching, watery eyes)  Receptors!  Allergy medicines contain “anti-histamines”

Actions that May Cause Disease Why? 1 Airborne pathogens are inhaled Flu, Common Cold 2 Physical Contact/ Sexual Contact Handshake, Touch nose, mouth can transfer virus to mucous membranes – cause virus to multiply. STD’s 3 Contamination of Food and Water E coli, Hepatitis A 4 Transmission through an animal Deer Ticks  Lyme Disease

 IR- non specific defense – redness, heat, swelling and pain  Histamine: mast cells release a “chemical alarm” which cause blood vessels to dilate  Interferons: a family of proteins produced by cells in response to becoming infected by a virus  What does a inflammatory response activate? -removing pathogens and cleans injured tissue

 First Line of Defense: “Barriers”  Second Line of Defense- Internal Non Specific  Third Line- “Targeted”

 Skin - Constantly growing and shedding hard to embed bacteria  Mouth, eyes, nostrils  Mucous Membranes -Inside trachea, stomach

 White Blood Cells- will identify what to attack and which “cell” to use  Inflammatory Response – site of the invasion( redness, swelling). Removes the pathogen and cleans injured tissue  Proteins- can attack invaders or halt their reproduction

 The Immune system – the system recognizes specific pathogens and defends against them.  Pathogens, cancer, chemicals  Specific Response!

2 nd Line of Defense :Types of WBC’s TypeFound?Role/ Job? Macrophages (large WBC) Interstitial FluidDestroy organism through “eating them” (phagocytosis) - Engulfs Neutrophiles Smaller and more numerous then macrophages Interstitial Fluid Also destroy by “eating them” release a chemical (like bleach) to destroy them – but this will also kill the neutrophile Natural Killer Cells Bloodstream -Recognize body cells which have been infected and target them -Play a key role in defending against cancer

TypeFound?Role/ Job? B Cells Interstitial fluid and blood -A protein that helps to bind to the antigen -Specific to attacking bacteria and viruses -has the ability to clone themselves Plasma Cells Lymphatic system-Secretes large amounts of antibodies -need to be activated by helper T cells in immune response

3 rd Line of Defense – WBC’s TypeFound?Role/Job? Helper T Cells Bloodstream-Secrete chemical to activate other WBC -Bind to infected cell Cytotoxic T Cells Bloodstream-Bind to infected cell- poke holes thus causing the cell to leak and die -Attack cells that are damaged Memory Cells Bloodstream 1 st response produces antibodies 2 nd response, remember and recognize pathogen -Long lasting lymphocytes

 Self Attack: body fails to recognize its own molecules  Rejection: Associated with  Common with heart, lung, and digestive organs  Skin grafts- “use their own skin” transplants

 A disease which specifically attacks the  It targets the  Deactivates other WBC’s  This is a type of autoimmune disease  The immune system turns against its own molecules  Other examples are Lupus,Multiple Sclerosis, and Lou Gehrig's disease Helper T cells Immune system