inflammation and repair Flashcards
what is injury?
an alteration in the environment that causes tissue damage. eg chemical, physical, microorganisms, nutritional deficiencies
natural (innate) defenses against injury
i. ) intact skin/mucosa is a physical barrier.
ii.) enzymes in saliva have an antibacterial activity.
iii.) flushing action of tears, saliva, urine and diarrhea removes foreign substances.
inflammation
a nonspecific response to injury; occurs in the same manner regardless of the nature of the injury
localized signs of inflammation
redness, swelling, pain, loss of normal tissue function.
systemic signs of inflammation
fever, leukocytosis, elevated C-reactive protein, lymphadenopathy
sequence of microscopic events
- injury to tissue
- constriction of microcirculation
- dilation of microcirculation
- increase in permeability
- exudate leaves microcirculation
- increased blood viscosity
- decreased blood flow
- margination and pavement in of WBCs
- WBCs (leukocytes) enter tissue
- WBCs (leukocytes) ingest foreign material.
hyperemia
increased blood flow in capillary of injured tissue;
will produce redness and heat
exudate
increase blood plasma and proteins in injured tissue;
helps dilute injurious agents but results in excess fluid in tissues - EDEMA
SEROUS exudate
mainly plasma fluids and proteins, few WBCs; thin, clear
purulent exudate (suppuration)
contains plasma fluids and proteins, tissue debris and many WBCs;
thick white-to-yellow pus
what can happen due to exudate?
swelling develops, drainage may occur through fistula; incision and drainage may be required; pressure from exudate and chemical mediators may cause pain;
how can blood viscosity increase?
it may increase due to loss of plasma fluids
what is margination?
white blood cells migrate to the periphery of the vessel.
what is emigration? (transendothelial migration)
the process by which WBCs escape from blood vessels through gaps in endothelial cells
what is chemotaxis?
directed movement of WBCs toward the site of injury
what is phagocytosis?
the process by which WBCs ingest and then digest foreign substances; may include pathogenic organisms and tissue debris
what are the six different types of WBCs?
- Neutrophils (PMNs)
- Monocytes (macrophages)
- Lymphocytes
- Plasma cells
- Eosinophils
- Mast cells
which WBC is first to arrive at site of injury?
Neutrophils (PMNs) are the primary cell in acute inflammation; most common
which WBC is second to arrive?
Monocytes (macrophages); monocyte(in blood) becomes a macrophage as it enters tissue inflammation
which WBCs are seen in CHRONIC inflammation and the immune response?
both lymphocytes (3) and plasma cells (4)
which WBCs are seen in both inflammation AND the immune response?
eosinophils (5) and mast cells (6)
which WBCs become predominant with chronic inflammation?
macrophages, lymphocytes and plasma cells
which WBc decrease in number?
circulating neutrophils
Which WBC is derived from stem cells in bone marrow and contains lysosomal enzymes?
Neutrophils (PMNs)
what is the function of neutrophils?
is phagocytosis and then enzymatic destruction of foreign substances;
neutrophils then perish; enzymes can leak causing further tissue damage