CHAPTER 12 Flashcards
immune system
the body’s defense against infectious organisms and other harmful invaders
self vs nonself
the immune system distinguishes between the body’s own cells and foriegn cells
antigen
any molecule that can stiulate an immune response
PAMPs (pathogen associated molecular patterns)
structures found on pathogens
PRRs (Pattern recognition receptors)
found on immune cells that recognize PAMPs
lymphatic system
system of vessels and organs that helps protect and maintain the fluid environment of the body
bone marrow
thymus
bm- produces blood cells, including immune cells
th- location where T cells mature
physical and chemical defenses
the body’s first line of defense is the skin and mucous membranes
chemical defenses are enzymes and acids
physical barriers
skin and mucous membranes prevent pathogens from entering
skin- keratin
mucous- mucus traps mo
chemical defences
example like lysozyme (in tears) and stomach acid that destroy or inhibit pathogens
defensive mechanisms in respiratory tract
nasal hair, mucus, ciliated epithelium, sneezing and coughing help prevent pathogens from entering the lungs
microbiome role
microbiota can prevent pathogenic mo from colonizing
urinary and vaginal defenses
urination and vaginal secretions help flush out mo
how does mouth protect
saliva washes microbes into the stomach
how do eyes protect themselves
tears and eye lubricants contain lysozyme, an enzyme that breaks down bacterial cell walls
blinking removes debris and mo
how does vomiting and defecation protect
expels harmful subtances, pathogens and toxins from the digestive system
sebaceous secretions
contain antimicrobial compounds that inhibit microbial growth on the skin
sweat
contains salt and antimicrobial peptides that inhibit microbial growth
lymph node
small bean shaped structure that filters lymph and contains lymphocytes
why do lymph nodes swell
swelling occurs when lymphocytes proliferate in response to detecting a pathogen or inflammation
can be a sign of infection, immune response or rarely cancer
blood composition
RBCs, WBCs, platelets
Plasma
stem cells in the bone marrow differentiate into:
myeloid lineage: RBCs, platelets, granulocytes
lymphoid lineage: lymphocytes
bone marrow transplants can
replace damaged stem cells, creating a new functional immune system
leukocytes
WBCs
types: granulocytes and agranulocytes
