IMMUNE 1 Flashcards
whats unique about the immune system?
it’s a functional system, not organ system
what is the immune system made up of
two intrinsic defense systems that act independently and cooperatively to provide resistance to disease
what makes up the innate defense system (nonspecific)?
first line - external membranes (skin/mucosa)
second line - internal defenses
when do internal defense start attacking
when 1st line has been penetrated and adaptive
systems are intertwined
what are examples of internal defenses
WBCs, phagocytes, natural killer cells, inflammation, antiomicorbial proteins, fever
how long does it take innate defense system to respond
minutes
whats the adaptive/specific defense system
3rd line of defense; attacks foreign substances
why does it take longer to activate adaptive/specific defense system
because proteins must be released during an innate response alerts cells of the adaptive system about the presence of a foreign substance
what are the different sections that the first line of defense surface barriers hold
skin (kernatinzed epithelial membrane), Mucous membranes (lines all body cavities), membrane secretions
why is the body broken into many different cavities
to improve defenses
what is skin resistant to
most weak acids and bases and toxins
what do the surface barriers serve as and secrete
serve as physical barriers; secrete protective chemicals
what are the four protective chemicals secreted by surface barriers
acid, lysozomes, mucins, defensins
where does the acid come from
skin, vaginal and stomach secretions; Inhibits bacterial growth
where do lysozomes come from
in saliva, respiratory mucus, eye lacrimal fluid
Enzymes destroy bacteria
where does mucin come from
in digestive and respiratory mucus
Traps microorganisms
what are defensins
antimicrobial peptides secreted from skin and mucous membranes
» Help control bacterial and fungal growth in exposed areas
what do little cuts elicit and enable
internal innate responses
what makes up the second line of innate defense
Phagocytes (macrophages and neutrophils)
Natural killer cells
Inflammatory response
Antimicrobial proteins
Fever
what are phagocytes - macrophages and neutrophils - derived from
white blood cells
what does the second line of internal defenses do
Kill pathogens and repair tissue
what do macrophages do
leave bloodstream in search of foreign substances
what do macrophages come from
monocytes that differentiated into them
what are neutrophils
type of WBC that becomes phagocytic after encountering foreign substances
what are three methods of pathogen destruction
Simple digestion by lysosomal enzymes (phagolysosome)
Respiratory burst: free radicals released to kill cells
Pierce pathogen membrane with defensins
what are natural killer cells
Defensive cells located in blood and lymph
what do natural killer cells kill
Can kill cancer and virus-infected cells before
the adaptive immune system is activated
how do natural killer cells kill
by inducing apoptosis in infected target cell
how do natural killer cells eliminate cancerous/infected cells
by detecting lack of “self” cell-surface receptors
what do natural killer cells secrete
chemicals that enhance the inflammatory response
whats the inflammatory response triggered by
any tissue injury
what does the inflammatory response prevent
the spread of damaging agents to nearby tissues
what does the inflammatory response dispose of
cell debris and pathogens
what does the inflammatory response alert
adaptive immune system and sets the stage for repair
what are the four cardinal signs of inflammatory response
redness, heat, swelling, pain
whats sometimes considered the fifth sign of inflammatory response
Impairment of function which may hinder joint movement
what do injured, stressed, and immune cells release
inflammatory chemicals: Cytokines, histamine, kinins, prostaglandins, leukotrienes and complement (group of plasma proteins)
what do inflammatory chemicals dilate
local arterioles
what do inflammatory chemicals release
capillary permeability
what do inflammatory chemicals attract
phagocytes
