Maintenance of Living Things

Remember, to be “alive” you need to carry out the eight life processes!

1. Respiration2. Regulation3. Repair/ Growth4. Reproduction5.Transport6. Excretion7. Nutrition8. 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

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!

2nd Line of Defense :Types of WBC’s

Type Found? Role/ Job?

Macrophages(large WBC)

Interstitial Fluid Destroy 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

Type Found? 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

3rd Line of Defense – WBC’s

Type Found? 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 1st response produces antibodies 2nd 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 diseaseThe immune system turns against its

own moleculesOther examples are Lupus ,Multiple

Sclerosis, and Lou Gehrig's disease

Helper T cells

Immune system