Advanced pathophysiology - NR 507
midterms
1st line of immune protection - answer physical, mechanical, and biochemical
natural or innate protection - born with it
constant, nonspecific, localized protection
intact skin and mucus membranes as well as sweeping, flushing, and peristaltic actions
secretions such as mucus, bile, tears, and urine provide nonspecific protections
natural microbiome ("good" bacteria) - naturally occurring flora also provide protection
2nd line of immune protection - answer Inflammatory response
natural or innate protection - born with it
immediate, nonspecific, localized protection at the site of invasion when 1st line of
protection breeched by injury or infection
includes white blood cells classified as phagocytes and other chemical mediators
3rd line of immune protection - answerlymphocyte production
adaptive or acquired immune protection - not born with it
slow acting, specific, systemic response to back up 2nd line of defense
Specialized WBC: lymphocytes - T-cells and natural killer cells - as well as other
chemical components
lymphocyte cells involved in 2nd line of immune response - answerbasophils,
eosinophils, neutrophils, sometimes referred to as PMNs (polymorphonuclear).
Monocytes which become macrophages when they're actively involved in an immune
response.
Mast cells which are a type of basophils that is typically not found circulating in the
bloodstream, but localized in our tissues.
,chemical mediators - answerhistamine,
leukotrienes,
interleukins,
interferons,
kinins,
prostaglandins,
and complement.
purposes of inflammatory response - answerFirst of all, it walls off the causative agent
to restrict further tissue damage.
Cells as well as chemicals released during the inflammatory response act to destroy
and remove the causative agent.
These chemicals also stimulate and enhance further immune response.
And finally, the inflammatory response will also promote healing and the repair process.
2 types of inflammation - answerAcute:
a short-term response associated with all types of tissue injury.
typically lasts less than two weeks.
Chronic:
his is long-term response associated with formation of scar tissue.
Chronic inflammation typically lasts more than two weeks.
vascular response of acute inflammation - answerInjury, or infection, triggers mast cells
that are located in our tissues, particularly in our skin, in our respiratory and GI mucosa,
to degranulate. And release chemicals including histamine which causes an immediate
vascular response:
It triggers constriction of large vessel walls. That causes an increased blood flow
directed into the capillaries. That increased flow of blood, which is also warm, causes
the injured area to become red and heat. And feel warm to the touch as well as possibly
some itching at that inflammatory site.
Histamine also triggers dilation of capillaries, and we see endothelial cell retraction. The
cells that make up the capillary walls start to pull apart from each other as the capillaries
dilate. This creates little tiny openings in the capillary wall, increasing the permeability,
and fluid leakage can occur that results in our third sign of inflammation, swelling or
edema.
white blood cell response of acute inflammation - answermast cells also release a
number of other chemotactic factors that act as signals to bring other white blood cells
to the area to help amplify increase this inflammatory response.
,in addition to the chemicals that they release, mast cells also contain enzymes that
allow them to synthesize even more chemical mediators from membrane phospholipids
that are released from damaged cells or even from the mast cell membranes
themselves. One of the key chemicals that is part of the cell membrane is something
called arachidonic acid.
arachidonic acid - answeras mast cells release enzymes, they can take the arachidonic
acid and convert it into things like leukotriene and prostaglandins.
Leukotrienes and prostaglandins function very similar to histamine as capillary vaso
dialators. But they have a prolonged effect.
And prostaglandins also functions somewhat like a neurotransmitter in that it stimulates
nerve endings to give us our fourth symptom of inflammation, pain.
PAMPs - pathogen associated molecular patterns - answerAntigens: substances that
trigger an immune response
Antigens are large molecules usually proteins lipoproteins or glycoproteins that are
foreign, nonself to the host immune system, something that our white blood cells have
not seen before.
The surfaces of bacteria, viruses, and other microbes are covered with many foreign
proteins.
DAMPs, damaged-associated molecular patterns. - answermany proteins that are
released from inside of our cells when they're damaged are foreign, our white blood
cells have not experienced or been exposed to these proteins before.
PRRs, pattern recognition receptors, - answersurfaces of white blood cells contain
special receptor sites - pattern recognition receptors, that continually interact with any
material they encounter to identify it as self or non-self.
So upon recognition of tissue invasions, the mast cells degranulate, histamine release
triggers vasodilation.
diapedesis. - answerDia, to move across like the diameter of something, pedesis, to
walk.
Circulating white blood cells, particularly the nutrifills are able to move across capillary
walls in large numbers through this process
chemotaxis. - answerwhite blood cells move towards the antigen through this process
Directional migration of cells following the chemical gradient of those foreign proteins
, phagocytosis. - answerthe white blood cell response of inflammation,
The primary phagocytic white blood cells are neutrophils and monocytes (which
becomes a macrophage).
involves several steps. The first is opsonization and adherence with the white blood cell
attached to the pathogen.
once a white blood cell has a good hold on that foreign material, it will engulf it. It will
literally surround and ingest the antigen. And the antigen enters the cell encapsulated in
a vesicle called a phagosome.
the phagosome will be literally moved into the WBC organelles called lysosomes
(garbage disposal of the cell)
And the phagosome containing the antigen will be digested by the chemicals that are
inside of those lysosomes, including lysozyme, a very powerful enzyme that breaks
apart bacterial cells, hydrogen peroxide, a variety of acids and other toxic chemicals.
And the phagosome containing the antigen will be digested by the chemicals that are
inside of those lysosomes, including lysozyme, a very powerful enzyme that breaks
apart bacterial cells, hydrogen peroxide, a variety of acids and other toxic chemicals.
next is egestion, the debris that the phagocytes have digested was left over will be
spewing out of the white blood cell where it'll be cleaned up by yet another one of our
white blood cells, the eosinophils.
The phagocytes the cells that have been actively involved in the digestive process have
worn out, they die. And they become what we know as pus.
neutrophils - answermake up about 70% of our white blood cell.
So they are typically the first cells to arrive at any type of invasion.
They're literally will start migrating towards that invasion site within minutes after the
invasion occurs, how directed by the release of chemicals that rapidly circulate through
our bloodstream.
Neutrophils will arrive at the invasion site in high numbers within a few hours.
can destroy anywhere from 5 to 20 bacteria before they wear out. They exhaust their
supply of digested chemicals
monocytes - answerMonocytes take a little longer to get there, but within 24 hours
they're also gonna be at that invasion site. And once they become actively involved in
the inflammatory response, we then refer to them as macrophages.