Blood Physiology Lecture 3 Flashcards
__________ is part of a bodys immune response
Inflammation
Inflammation
The non-specific innate immune response to tissue injury initiated
Purpose of inflammation
to heal and fix injury, by descruting of non-self agents and formatoin of scar tissue (fibrosis)
Inducers of inflammation may include (not very important) (5)
-Cut on skin surface
-Bullet wound
-injuries due to sun burn
-infected stutures during surgery
-infection of tonsil by cold virus
Physical characteristics of inflammation
- Redness
- Swelling
- Heat
- Pain
- Loss of function
3 components of inflammatory pathway in order
inducers ___> sensors ——> mediators
inducers
causitive agents, initiative inflammatory response
sensors
sense the presence of foreign non-self agents
-activate mediaters
mediators
take over the task of repare
the first three signs of inflmmation are associated with changes in __________
vessels or vasculature
first three steps of inflammation
- Redness
- Swelling
- Heat
Steps following injury in vasculature:
- Histamine is released by mast cells
- Histamine causes vasodilation of blood vessels, which increases blood flow causing the redness and heat of inflammation
- Histamine causes blood vessels to become leaky or more permeable, allowing proteins and fluid to move to the extracellular space. The fluid
causes the swelling of inflammation.
where are mast cells found
in the skin tissue
Histamine is a ___________
inflammatory mediator
There are _______ major components of acute short term inflammation
2
What are the 2 components of acute short term inflammation?
- Vascular Events
- Cellular Events
Vascular events refers to ________
refers to events involving blood vessels
Cellular Events refer to ______
refers to events associated with cells
Vascular event steps (5)
-Release of histamine
-Local blood vessels dilate
-Local blood vessels become leaky
- Accumulation of protein and fluid in the extracellular space
- Inflammatory mediators are released: bradykinin, prostaglandins,
complement proteins
Cellular Events steps (
bradykinin and prostaglandins may cauase feeling of _______ at injury
pain
cellular events steps (3)
- as vascular changes occur, resident macrophages entrap and kill pathogens, release chemical
signals - Increased movement of WBCs (neutrophils and monocytes) into
infected area - Phagocytosis and destruction of foreign agent
The purpose of inflammation is to _________ (3)
destroy non-self agents
healing/resolution
fibrosis
The main goal of inflammation in terms of cellular events is to __________
bring WBCs to the inflamed tissue and kill the
“non-self” agent
Cellular events that bring WBC to inflamed tissue and kill the non-self agent steps (8):
- Margination of WBCs – move to edge of blood vessels
- Tethering and rolling of WBCs inside blood vessel – attaching of WBC to
endothelial cells of the blood vessels and slow rolling along the vessel - Activation of WBCs and endothelial cells – involves expression of proteins on the
surface of neutrophils and endothelial cells
events – refers to events associated with cells - Arrest/firm attachment of WBCs to endothelial cells – neutrophils bind to complementary proteins on endothelial cells and stop rolling
- Emigration/diapedesis - white blood cells squeeze in between adjacent endothelial cells to exit out of the blood vessel and move into the tissue spaces
- Chemotaxis of WBCs – WBCs move toward the site of inflammation by chemotaxis, a process of cell movement that occurs in response to specific molecules or chemical attractants
- Recognition of “non-self” by WBCs - at the site of infection, WBCs recognize foreign agents by recognizing chemical molecules on their surface
- Phagocytosis of “non-self” pathogen by WBCs – process by which foreign pathogens or bacteria are engulfed by neutrophils
Chemotaxis in neuraphils moving :
the ability of WBCs to move against a concentration gradient (low → high
concentration) in response to chemical factors; they move towards the source of a
chemotactic substance
Chemotactic factors (chemo-attractants) (WBC)
Chemical factors that attract WBCs to the site
of inflammation
There are many factors that help in the movement of WBC’s to ___________
the source of infection
Phagocyte
a cell that can eat other non-self pathogens or dying cells by engulfing
them with temporary cytoplasm filled extension of the plasma membrane
(pseudopodia).
examples of phagocytic cells (4)
- Monocytes
- Macrophages
- Dendritic Cells
- Neutrophils
Phagocytic cells, like macrophages, have receptors called __________
pattern recognition receptors,
or toll-like receptors
What to pattern recognition receptors do?
Receptors recognize a specific pattern of molecules expressed on bacteria, and
therefore do not have to recognize a specific bacteria
Opsonins
Molecules added to the surface of a bacteria to help in speeding up the rate of phagocytosis by macrophages or other phagocytic cells
opsonins may be ______
antibodies or complement-type proteins
Opsonization
Coating of the bacteria with opsonins (either antibodies or complement-type
proteins) produced by the host body which then facilitates the attachment and phagocytosis of the bacteria by the phagocytic cell.
Opsonins are produced by ______
self or host body
Neutrophils play an important role in _______
the immune response
2 ways neutrophils kill bacteria?
- Oxygen-dependant process
- Oxygen-independant process
Oxygen-dependant killing
corrosive oxygen free radical products are
synthesized to destroy a foreign body
Oxygen-independant killing ______
uses different bactericidal enzymes
Types of bactericidal enzymes in oxygen-independent killing:
- Lysozymes
- Lactoferrin
- Defensins
Lysozymes
enzymes which work inside phagolysozomes to degrade entire bacteria by proteolytic breakdown
Lactoferrin
binds to iron and reduces iron in the environment so that bacteria cannot grow
Defensins
drill holes on the surface of a bacteria, killing it
