Warm up: What makes us sick?

Goals & Objectives Define pathogen Distinguish between viruses and bacteria Explain how pathogens can spread in a population

KEY CONCEPT Germs cause many diseases in humans.

Germ theory states that microscopic particles cause certain diseases. Germ theory proposes that microorganisms cause diseases. proposed by Louis Pasteur led to rapid advances in understanding disease

Disease-causing agents are called pathogens: Bacteria Viruses Fungus (fungi) Protozoa Parasites Prions

Bacteria are single-celled organisms release toxic chemicals that destroy cells compete with the body’s cells for nutrients

Viruses are non-living pathogens force host cells to make more viruses made of genetic material surrounded by a protein coat

Fungi can be multicellular or single-celled. take nutrients from host cells occur in warm and damp places

Protozoa are single-celled organisms. use host cells to complete their life cycles take nutrients from host cell

Parasites are multicellular organisms. grow and feed on a host possibly kill the host

Different pathogen cause common infectious diseases.

Pathogens can enter the body in different ways. Pathogens can be transferred by direct or indirect contact. Indirect contact does not require touching an infected individual. touching an infected surface breathing in infected air

Direct contact requires touching an infected individual. Includes: kissing sexual intercourse hand shaking tick Vectors carry a pathogen and transmit it into healthy cells. ex: ticks

Next: Turn to page 940-941 and draw the timeline of the history of medicine and turn it in when you are finished. You will have an exit slip today as well.

Exit Slip: Answer the following questions: Define pathogen Distinguish between viruses and bacteria Explain how pathogens can spread in a population