Human Biology ch 15

Infectious disease of the brain our bodies can't fight - misfolded proteins

organisms that cause disease

when a pathogen finds a host

small - can only be seen with a microscope

single cell organisms - prokaryotic

small round extra chromosonal DNA

composed of carbohydrates and proteins

helps bacteria attach to cells within tissues they infect

help bacterial cells attach to each other and pass genes

how bacteria reproduces

• chromosome copies
• chromosomes attach to plasma membrane
• starts to separate-new cell wall created
• cell growth
• indentaion and separation

true

effects of toxins secreted by bacterial cells

• natural selection through overuse
• some bacteria carry genes that allow them to be resistant

deadly infection that resists antibiotics

• lethal bacteria if inhaled
• lives in soil
• infectious but not contagious

• affects nervous system
• soil dwelling

• lives in intestines
• comes from eating undercooked meat

• produces toxins that affect nervous and muscular system
• found in soil

• lives on skin
• causes infections

• not living
• can't reproduce by themselves - need a host cell
• a strand of DNA and a protein coat

• can't reporduce by themselves
• not composed of cells

protein coat surrounding a virus

• made of cell membrane from host cell
• may contain protein

a virus gains access to cell by fusing its envelope with the host's cell membrane

virus that is dormant in the body

transmitted by mosquito, affects brain and spinal chord - paralysis

• tapeworm
• athlete's foot
• jock itch
• malaria
• giardiasis
• schistomiomiasis

water and food contamination w/feces

raw or undercooked food

naturally occuring protein produced by brain cells that when misfolded causes spongiform encephalopathy

water born cyst, causes severe diahrrea and gas

carried by fresh water snails, caused by tapeworms

from ingesting raw or undercooked beef, causes intestinal pain and diahrea

nerve cells clog with misfolded proteins and cease to function, cells burst and infect other cells

mosquito-transmits through intermediate organism

• direct contact
• indirect contact
• vector-borne
• inhalation
• ingestion

• skin
• mucus membranes
• don't target specific pathogens

• white blood cells
• inflammation
• defense proteins
• fever
• internal - doesn't target specific pathogens

• lumphocytes
• attack specific pathogens

non specific cells attack tumor cells and virus invaded body cells on first exposure

• circulate in blood
• help other defense mechanisms

• white bood cells
• travel through body moving in spaces between cells and tissues or transported via blood andn lymph node system

• tonils and adenoids
• thymus
• bone marrow
• spleen
• lymph nodes
• lymphatic vessels

molecule foreign to host and stimmulates immune system

t cells when antigen is present in body

b cells -when an antigen is present secrete antibodies

bind to and inactivate antigens

• babies have passive immunity
• adults have active - accumulated from an individual's lifetime

immune response that occurs without a pathogen

ability to respond to an infection

true

true

a person's immune system attacks itself

• MS
• diabetes

protection afforded by B cells

• T cells
• immunity dependent on involvement of cells

• T4 cells
• boosters of immune system
• detect and alert B and T cells that infection in occuring