Disease Pages

Disease  Does not allow the body to function normally  Can affect individual organs or an entire body system  Divided into two groups – infectious and non-infectious

Infectious Disease  A disease that can be passed from organism to organism  Caused by tiny organisms called PATHOGENS

4 KINDS OF PATHOGENS  Bacteria  Viruses  Fungi  Protist

Pathogens  Bacteria, viruses, protozoans, fungi, and other parasites called pathogens are capable of causing a change that disrupts the homeostasis in the body.

Transmission of Pathogens  Pathogens can be transmitted to a host from a reservoir four main ways; 1.By direct contact; exchange of body fluid especially during sexual intercourse 2.By an object; people handle contaminate objects then touch face, nose, eyes, etc… 3.Through the air; person coughs or sneezes spreading droplets which are then inhaled 4.By a vector; insects such as mosquitos, ticks spread pathogens between hosts or reservoirs

Pathogens can come from  Another person

 Contaminated objects

 Animal bite

 Environment

Immune System responsible for  distinguishing (telling the difference) between the different kinds of pathogens  Reacting to each kind according to its type

When a pathogen enters the body  It works by damaging individual cells within the organs  In some cases it attacks an entire body system

Some Infectious Diseases You Should Know  Colds  Flu  Strep Throat  Athlete’s Foot  AIDS

Colds  Illness caused by a viral infection located in the respiratory system  The cold virus multiplies and attacks the mucous membranes of the nose and throat causing the common effects of the cold (sore throat, runny nose, fever…)  Cold can not be treated with an antibiotic because it is caused by a virus

Flu  Influenza, commonly known as “the flu”, is a highly contagious viral disease of the respiratory system  Typically causes fever, muscle aches, and a more severe cough than the common cold and usually lasts longer

Athlete’s foot  Common fungal infection of the skin of the feet  May be contracted from public environments  Grows in the warm and moist environment usually between the toes  Difficult to cure

AIDS  Acquired immunodeficiency syndrome (AIDS)  Caused by the human immunodeficiency virus (HIV)  The virus attacks the cells in the immune system making the organism unable to fight off other pathogens that may attack the body

Strep Throat  Contagious disease caused by bacterial infection  Symptoms include fever, pain, redness and swelling of the throat and tonsils  May produce mild or severe symptoms

What was the source of the pathogen?  Salmonella  is a bacterium

What is the first defense?  Source of the pathogen  Contaminated food

What does the body do next to try and get rid of the pathogen?  Stomach acid destroys some of the bacteria  Macrophages try to destroy the Salmonella

How does Salmonella attack the body?  Enters the cells of the villi and destroys them  The destroyed cells release distress chemicals What causes the diarrhea?

How does Salmonella cause your body to ache? The waves of peristalsis are so rapid that the large intestine is unable to absorb the water

Does the medicine kill the Salmonella? The chemicals released from the cells leak into the blood stream and go into the muscle tissue

How does the immune system begin to respond to the Salmonella invasion?

 The immune system identifies the pathogen and produces helper cells  Helper cells “help” the macrophages to do their job – destroy the Salmonella

DiseaseCause Affected Organ Transmission SmallpoxVirusSkinDroplet InfluenzaVirus Respiratory system Direct contact HIV/AIDSVirus Immune system Body Fluid Hepatitis BVirusLiverBody Fluid TetanusBacteria Nervous system Puncture Wound Strep ThroatBacteria Respiratory system Droplet TuberculosisBacteriaRespiratoryDroplet

Antibiotic Medications  What are they and when are antibiotics used?  Antibiotics are for bacterial infections (Monera). Some bacteria can make another organism sick. The antibiotics help the immune system fight the infecting bacteria (in advanced animals).

Antibiotic Medications  Where do antibiotic medications come from?  Fungi! Fungi naturally secrete chemicals which attack bacteria. This allows fungi to compete with bacteria that want to decompose the same food source.  Penicillin is an antibiotic medication derived from the mold (fungus) called Penicillium. Penicillium

Vaccines  What are they and when are vaccines used?  Vaccines are not medications. Vaccines contain a mixtures of dead and/or weakened viruses (or bacteria). Vaccines train the immune system (advanced animals only) to recognize an infective virus and destroy the virus before the animal can become sick.  Vaccines must be given before illness, which is why children, pets, and overseas travelers are given vaccines.

Common Vaccines  Children: Measles, Whooping cough, Chicken pox  Pets: Rabies  World Health Organization: Rotavirus Rotavirus  Adults and children: Influenza, Hepatitis Influenza  College students: Meningcoccal meningitis  Devastating viral diseases no longer common due to vaccines: polio, small pox  There is no vaccine for HIV (AIDS) or the common cold (rhinovirus). common cold common cold

The Careful Use of Antibiotics  Antibiotics do not fight viruses!  Antibiotics should be not taken for anything other than a bacterial infection.  Only take antibiotics prescribed by your doctor and always finish the entire prescription.

What is antibiotic resistance?  Overuse or incorrect use of antibiotics can lead to antibiotic resistance, which is dangerous and can be harmful to all organisms in a population.  Antibiotic resistance is an inherited trait in bacteria which makes them very difficult to kill with antibiotic medications.  How can this happen? Discuss!

Non-infectious Diseases  Not caused by pathogens in the body  Not spread from organism to organism

Non-infectious Diseases are caused by malfunctions in the body.  Heredity – information you get from your parents  The environment – examples are sun, radiation, chemicals  Lifestyle choices – smoking, drugs, alcohol

Types of Noninfectious Diseases  Diabetes  Asthma  Parkinson’s disease  Skin Cancer

Diabetes AAAA disease that results in glucose (sugar) level being higher than normal. IIIIt is caused by the person’s inability to either produce or use properly a natural chemical made in the body (pancreas) called insulin.

Diabetes may lead to  Kidney disease  Heart disease  Vision problems

High levels of blood sugar lead to disorders  Like an increase in problems with circulation

Parkinson’s Disease  Disease of the nervous system that occurs when nerve cells in the brain stop functioning properly, affecting the muscular system

Parkinson’s Disease  Major symptoms  Severe shaking (tremors)  Disabilities involving movement  At present, there is no cure

Skin Cancer  Disease in which skin cells found in the outer layers of the skin become damaged.

Factors that lead to Skin Cancer  Damaging ultraviolet rays (UV) from the sun or tanning beds  heredity

Asthma  Affects the lungs and the airways that deliver air to the lungs  Causes periodic attacks of wheezing and difficulty breathing

Asthma attacks  Occur when the airways become inflamed in response to a stimulus, such as dust, mold, pets, exercise, or cold weather  Some attacks start for no apparent reason