Chapter 17 Flashcards
Pathogens
Types ?
Disease causing organisms
Bacteria
Eukaryotes
Viruses
Bacteria vs viruses
Bacteria: prokaryotes, grow exponentially
Viruses: not alive, DNA or RNA surrounded by a protein coat
Pathogens transmission?
Direct contact Indirect contact Vectors Inhalation Ingestión
Direct contact
Exchange of body fluids
Shaking hands
Indirect contact
Contact with contaminated objects
Vectors
Intermediate organism carries pathogen from one person to another
Ex: bats, mosquito
Body’s first line of defense
Physical and chemical barriers
Physical barriers?
Skin
Mucus membranes
Chemical barriers
Tears Sweating Saliva Skin oils Stomach acid
Body’s second line of defense
Non-specific responses to infection or tissue damage
White blood cells eat or destroy non-self cells
Inflammation
Fever
Body’s third line of defense
Specific defenses against specific pathogens
Produce antibodies
Target infected and non-self cells directly Ake destroy them
Antibodies
They tag antigens for immune cells to destroy
Antigens
Foreign substances
Antibody-mediated immunity
Produce antibodies :attack to pathogen and prepare it for destruction
Produce memory cells: present in body until pathogen reappears
B-lymphocytes
Cell-mediated immunity
A specific immune response to infected, cancerous, or non-self cells
T-lymphocytes do the dirty work
