How we protect our bodies 4 The Immune

How we protect our bodies…. #4 The Immune and Integumentary Systems

Pathogens 1. Microscope organisms are everywhere a. MOST are not harmful Microscope organisms are everywhere 2. Disease causing microorganisms are called pathogens

The Immune System • How does our body protect itself from pathogens? • The immune system – Nonspecific defenses – Immune response

3. Nonspecific defenses a. With nonspecific defenses the body does NOT target particular pathogens b. The first lines of defense are your SKIN and mucous membranes! c. If a wound occurs an inflammatory response may occur and an increase in temperature i. Histamines cause blood vessels to dilate (swelling can occur) ii. Blood flow to the area increase so white blood cells can attack pathogens iii. The body temperature rises…most pathogens only grow in a particular temperature range (close to NORMAL body temperature)

4. White blood cells (specfic) a. Pathogens carry antigens which the body recognizes as an invader b. Three kinds of white blood cells that attack invading pathogens (there are more): i. Neutrophils - engulf and destroy pathogens …when they engulf the bacteria, they release a chemical to kill the bacteria, it also kills the neutrophil ii. Macrophages – ingest/kill pathogens & remove dead cells/other debris from the body iii. Killer T cells - large white blood cells-attack cells that are infected with pathogens to prevent spreading

Neutrophils – kamakazi pilots Macrophages – pacman Killer T cells – snipers (Write these to the side of your papers! To help you remember!!)

5. The immune response a. If an invading pathogen is not destroyed by the nonspecific defenses…the immune response kicks in… b. It is a series of invents that targets specific pathogens

5. C. What was our first line of defense again? The skin!!! d. The skin is your largest organ i. The skin along with your hair and nails make up the integumentary system

Be able to identify these parts on a diagram!!

6. The Layers of the Skin a. Epidermis - outermost layer…dead skin that makes skin tough and waterproof b. Dermis - made only of living cells…nerve cells, muscle cells, blood vessels, skin cells, hair follicles c. Subcutaneous tissue - mostly fat, acts as a shock absorber, insulation, stores energy and anchors the skin to the organs/muscle below

7. Relationships a. What body system is important in carrying white blood cells? Circulatory system b. Which body system(s) is(are) protected by the immune system? ALL of them!!! c. How are the immune and integumentary systems closely related? The skin is our first line of defense against infections. d. If something happened to our skin and we were no longer waterproof, how might this affect the circulatory system? As we lose water, our blood will become thicker…it is mostly water!

The Nervous System

The Nervous System • How do we know when to eat? • How do we know if we are touching a hot stove? • How does our body control breathing, the heart beat, and all other functions without our thinking about them? • The answer to all of these is the nervous system

The Nervous System 8. Our nervous system is how all of the parts of our body communicate with all of the other parts…its why we aren’t a bunch of separate parts doing their own thing….

9. Neurons a. The cells in the nervous system are called neurons b. Neurons contain a cell body with a nucleus 10. They also have dendrites (dozens of them) that receive signals either from other neurons or from the environment 11. They have an axon (one) as well that sends the signal on to the next neuron (away from the cell body)

A typical neuron

12. Nerve impulses a. A bundle of axons make up nerves b. Nerve impulses travel really quickly (250 miles per hour… 400 km per hour) c. When they get to the end of an axon they must cross the synapse…the gap between the neurons d. They do this by causing chemicals (neurotransmitters) to be released that cross and create a new impulse at the other side

13. Structures of the nervous system a. Neurons are the smallest parts of the nervous system but they come together to form two parts i. The central nervous system: The brain and spinal cord ii. The peripheral nervous system: The smaller nerves that send impulses to and from the organs (sensory neurons) and the muscles (motor neurons)

Questions… 14. How is the nervous system involved a. in controlling your digestion? b. helping you play soccer? c. helping you read a book? d. in controlling our heart rate?