Immuno Test 1 part 2 page 36 till end Flashcards
Inflamation is defined as?
the reaction of vascularized living tissues to local injury. The vascular and cellular events that highlight actue inflammation serve to deliver mediators of host defenses to sites of microbial invasion and/or tissue injury.
Inflammation is always an evoked response set in motion by________
It occurs only in ____.
some kind of a stimulus, eg tissue injury. It occurs only in living tissue.
Cardinal signs of Acute Inflammation?
1.) Rubor- redness (heat not fever) 2.) tumor- swelling edema 3.) Calor- heat 4.) Dolor- pain 5.) Functio laesa- loss of function
The local inflammatory response is always accompanied by_____________.
systemic changes collectively called the acute phase response or the systemic inflammatory response syndrome.
Systemic responses to infection are due to the ?
actions of proinflammatory cytokines such as tumor necrosis factor, interleukin-1 and interleukin-6 secreted by activated macrophages, mast cells, etc.
What are some other cytokines that also participate in the acute phase response?
colony stimulating factors that stimulate the bone marrow to produce more white blood cells.
What does the acute phase include?
1.) Fever- heat doesn’t allow replication 2.) Leukocytosis (hematopoiesis) more WBC 3.) Increased synthesis of acute phase proteins 4.) decrease in the plasma concentration of iron. High concentration of free iron enhances bacterial replication. (battle between us and microbes takes iron away) 5.)Decrease in appetite. May deprive pathogens of nutrients, especially minerals, needed for their proliferation 6.) increased secretion of many hormones, notably ACTH and cortisol
What are acute phase proteins ?
plasma proteins whose concentration change by at least 25% during inflammation.
Some proteins decrease in plasma concentration and are called?
negative acute phase proteins Ex: albumin
Where are acute phase proteins synthesized? What roles do they have?
mostly by the liver. The proteins play various roles in the innate immune response to infectious agents.
What are some acute phase proteins?
1.) complement proteins 2.) C-reactive protein- binds to bacteria and promotes their uptake by phagocytic cells, a process referred to as opsonization. 3.) Mannose- binding protein (more opsonization, also activation of classical pathway) 4.) iron binding proteins (haptoglobin, transferrin, lactoferin) 5.) lipopolysaccharide- binding protein (increased response to G- bacteria)
What does the microvasculature consists of? What follows after tissue injury?
the afferent arterioles, the capillary networks and the efferent venues. initiation of inflammatory response at the capillary and post capillary venules.
in acute inflammation what is the initial response of arterioles? What happens within a few minutes?
transient vasoconstriction, mediated by neurogenic and chemical stimuli. Vasodilation occurs a few minutes later, increasing blood flow to inflamed area.
What are post capillary venules?
the venules are the primary anatomic site for inflammation-related leakage. The junctions between the endothelial cells are more permeable than those in the capillaries, additionally the endothelial cells are more sensitive to vasoactive mediators.
What are chemical mediators of inflammation?
they are chemical messengers that enhance blood flow, increase vascular permeability, or induce the emigration of leukocytes from the blood stream to the site of tissue injury.
What are examples chemotactic factors? and what do they lead to?
*C5a *Leukotriene B4 *Formylated peptides *Chemokines IL-8 CXCL8 *PAF -lead to recruitment and stimulation of inflammatory cells
The inflammatory response may have 3 outcomes?
1.) elimination of the causative agent 2.) walling off of the inflammation from the rest of the body with subsequent healing of the lesion 3.) persistence of the causative agent, leading to chronic inflammation or spread throughout the body.
Cellular sources of chemical mediators of inflammation?
Platelets, connective tissue mast cells, basophils, neutrophils, endothelial cells, fibroblasts, monocyte/tissue macrophages, injured tissue.
Many mediators carry out their biologic activity by?
binding to specific receptors on target cells. Most functions can be elicited by multiple mediators and most mediators serve multiple functions.
Many mediators exert their effects______ and do not circulate systemically in high concentration except in unusual circumstances.
locally
What system of checks and balances limit the extent of the inflammatory response and hence tissue injury?
Many mediators have short tissue half lives. They quickly decay or are inactivated by enzymes or inhibited.
LPS released from the cell wall of Gram-negative bacteria is recognized and bound by….?
lipopolysaccharide binding protein present in plasma. LBP enhances the efficiency of transfer and presentation of LPS to the CD14 receptor on macrophage cell membrane, resulting in macrophage activation.
The activated macrophage synthesizes and secretes vasoactive mediators of inflammation including???
IL-1 IL-6 CXCL-8 TNF alpha, PAF
Nitric oxide is an important mediator of inflammation. what does it cause?
it causes vasodilation by relaxing vascular smooth muscle, reduces platelet aggregation and adhesion, and is a potent microbicidal agent. It is produced by activated endothelial cells and activated macrophages.









































