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PathologyIExam3ch4inflammationch2disturbancesincirculation.pptxINFLAMMATION
Inflammation Defined:
- a tissue reaction to irritation, infection or injury
- a morbid change or series of reactions produced in the tissues by an irritant
- there must be death of cells for this to occur
A. FUNCTIONS OF INFLAMMATION
1. to destroy the irritating agent and remove it
2. if that fails, the process will attempt to keep the irritant localized
3. to provide the mechanisms for repair or replacement of damaged tissue
B. CAUSES OF INFLAMMATION:
1. Physical Irritants
2. Chemical Irritants
3. Infectious Agents
4. Immunological Reactions
C. CARDINAL SIGNS/SYMPTOMS
OF INFLAMMATION:
1.
2.
3.
4.
5.
Calor -
Rubor -
Dolor -
Tumor -
Altered Function
Heat
Redness
Pain
Swelling
Functio laesa -
D. PROCESS OF INFLAMMATION:
1. Congestion
- a form of pathological active hyperemia
- a vascular reaction
- the arteries dilate allowing excess blood or tissue fluid into the affected organ or tissue
- the release of histamine causes the capillary walls to become more permeable
*
- to “flush out” the tissue of any foreign matter
2. Exudation
- the outpouring of normally intra- vascular cells into injured tissue
- Chemotaxis occurs here
- dilutes the toxin
- the attraction of white blood cells to the site of inflammation
- fluid or cellular debris exuding from blood vessels and deposited in tissues
3. Suppuration
- the formation of pus
- is often due to the presence of pyogenic bacteria or some other infectious agent
- a protein-rich fluid containing white blood cells and cell debris
- if there is not a need for extra leukocytes to fight an infection, this step may not occur
4. Resolution
- the termination of the inflammatory response with the affected part returning to its normal state
occurs by either physiological or pathological regeneration
E. INFLAMMATORY LESIONS:
1. Abscess
a circumscribed collection of pus
- surrounded by a wall of inflammatory tissue
- there are many different types
E. INFLAMMATORY LESIONS:
1. Abscess
2. Ulcer
- an open sore or lesion of the skin or a mucous membrane accompanied by sloughing of inflamed necrotic tissue
Ex.
decubitus ulcer
- bed sore
3. Furuncle (boil)
- an abscess or pyogenic infection of a sweat gland or hair follicle
4. Carbuncle
- several communicating boils with the production and discharge of pus and dead tissue
- often located deep in the sub-cutaneous tissues of the neck or buttocks
5. Cellulitis or Phlegmon
- a diffuse, non-circumscribed, inflammatory infiltration of the tissues
- also usually subcutaneous
- forms pus pockets
5. Cellulitis or Phlegmon
6. Pustule
- a small, circumscribed elevation on the skin containing pus
- as in a pimple
7. Vesicle
- a small, circumscribed elevation of the skin containing a thin, non-purulent fluid
- commonly known as a blister
F. Types of Lesions based on the composition of the exudate:
a. Serous
- protein-rich with white blood cells
F. Types of Lesions based on the composition of the exudate:
b. Purulent
- pus caused by pyogenic organisms
F. Types of Lesions based on the composition of the exudate:
c. Hemorrhagic
- red blood cells
Inflammatory exudates are formed by the accumulation of cells and fluid from the lumens of blood vessels in the injured area. The microbe causing infection, if present, plays an important part in determining the nature of the exudate.
G. Postmortem Conditions of Inflamed Tissue
1.
2.
3.
4.
Virulent Bacteria
- for pus formation
Rapid Decomposition
Reduced Circulation
Possible Odor
DISTURBANCES
IN
CIRCULATION
A. Edema or Dropsy
- accumulation of fluid in the tissues
1. Causes
a.
b.
c.
d.
increased permeability of capillary walls
increased capillary pressure due to venous obstruction or heart failure
inflammatory conditions
fluid and electrolyte disturbances
A. Edema or Dropsy
2.
a. Anasarca
- generalized edema in the sub-cutaneous tissues
- often seen with:
- Heart Failure
- especially around the feet and ankles
- Liver Disease
- Kidney Disease
EXAMPLES
- may be the result of generalized passive hyperemia
b. Ascites
- serous fluid in the abdominal (peritoneal) cavity
d. Hydropericardium
- serous fluid in the pericardial sac
e. Hydrocele
- serous fluid in a sac-like cavity
- often occurs in the scrotum due to inflammation of the testes or other parts
c. Hydrothorax
- serous fluid in the thoracic or pleural cavity
B. Hyperemia or Congestion
- an excessive amount of blood in a body part
B. Hyperemia or Congestion
- an excessive amount of blood in a body part
1. Active or Arterial Hyperemia
- due to an increased arterial supply
Physiological active hyperemia
- supplies increased nourishment to organs or tissues doing increased work
b. Pathological active hyperemia
- initiates inflammation and forms one of the most important features of inflammation
*
2. Passive or Venous Hyperemia
- due to decreased venous drainage or a blockage
- always pathological
Local
- usually due to an obstruction of a vein by a thrombus or embolus, thickening of the vessel wall, or pressure from an outside lesion such as a neoplasm or enlarged organ
- may lead to local edema
b. Generalized
- the flow of blood through the lungs is often reduced
- may lead to anasarca
- therefore, less blood is oxygenated
- usually due to a heart disorder
- anoxemia
- less oxygen is in the tissues
- hypoxia
- leading to shortness of breath
- and a bluish discoloration of the skin, lips, nail beds and mucous membranes
- dyspnea
- cyanosis
C. Ischemia
- a crucial temporary reduction in the arterial supply of blood to a given part of the body
- a local anemia caused by obstruction of arterial blood supply
Causes:
2.
3.
4.
thrombosis
embolism
athero/arteriosclerosis
outside pressure on an artery
Ischemia may lead to or cause an:
- Infarction
- the formation of an area of necrosis caused by an obstruction of arterial supply
D. Thrombosis
- the formation of a solid mass or blood clot within the heart or a blood vessel during life
- formed from one or more of the normal constituents of the blood
1. Difference between a thrombus and a postmortem clot:
Thrombus
- a mass attached to a vessel wall
Postmortem clot
- not attached to a vessel wall
2. CAUSES OF THROMBOSIS:
a.
b.
c.
d.
Injury to the blood vessel by trauma, degeneration, or inflammation
Slow rate of blood flow
Disease of the blood itself
Alterations in blood composition
3. LOCATIONS OF THROMBI:
- the most common sites for thrombus formation are in the
- Heart & Veins!!!!
- when thrombosis of an artery does occur, the most common sites are the:
a.
b.
c.
cerebral arteries
coronary arteries
aorta
4. CHANGES IN THROMBI:
a. Digestion or Resolution
- absorption of part or all of the thrombus by the activity of leukocytes and/or enzymes
4. CHANGES IN THROMBI:
b. Organization
- the proliferation of a vascular and fibrous tissue is stimulated
- characteristic of arterial as opposed to venous thrombosis
- the thrombus is changed into a mass of fibrous tissue
4. CHANGES IN THROMBI:
c. Canalization
- capillaries taking part in the organization dilate to form new canals through which the blood can pass
Fibrous tissue
New canals forming
4. CHANGES IN THROMBI:
d. Calcification
arteriosclerosis
- hardening of the arteries
- deposits of calcium salts in the veins
- forms a phlebolith
- a “stone” in the veins
e. Fragmentation
- a thrombus attached to a vessel wall becomes fragmented
- may break loose to form an embolus
4. CHANGES IN THROMBI:
f. Septic softening
- a thrombus infected with pyogenic bacteria may become softened and disintegrate
- may possibly be converted into an abscess
4. CHANGES IN THROMBI:
As a general rule:
MOST THROMBI ARE ASEPTIC
5. CONSEQUENCES OF THROMBOSIS:
a.
b.
c.
d.
Ischemia
Infarction
Passive Hyperemia
Gangrene
E. Embolism
- obstruction of a blood vessel by foreign matter carried in the bloodstream
- the object is known as an embolus
1. TYPES OF EMBOLI:
a. Fragment of thrombi
- post-operative thrombosis is of special danger
e. Fat
- fat cells in the bone marrow or fat deposits in soft tissue are ruptured by trauma and broken into smaller globules which are then sucked into torn veins
c. Tumor Cells
d. Animal Parasite
b. Agglutinated Bacteria
g. Foreign bodies
h. Atheromatous material
- from a vessel wall
i. Clumps of fibrin
- from diseased heart valves
f. Gas or Air
results from operations on the neck or thorax, blood transfusions
when a vein is only partially severed preventing collapse there is danger of an air embolism
2. CONSEQUENCES OF EMBOLISM
- sudden death in coronary or cerebral arteries
- no damage if part has good collateral circulation
a.
b.
c.
d.
Ischemia
Infarction or gangrene
Spread of infection
Spread of tumors
F. Hemorrhage
- the escape of blood from the vascular system
1. Per rhexis
- due to a ruptured blood vessel or heart chamber
2. Per diapedesis
- the passage of blood cells through the unruptured walls of vessels
3. CAUSES OF HEMORRHAGE:
a.
b.
c.
d.
Trauma
Disease of the blood vessels
Hypertension(high blood pressure)
Diseases of the blood
4. TERMS THAT APPLY TO HEMORRHAGE:
a.
- small pinpoint hemorrhages
- due to leakage from a capillary
Petechia
4. TERMS THAT APPLY TO HEMORRHAGE:
b.
Ecchymosis
a small purplish patch caused by extravasation of blood into a tissue
(a bruise)
c.
Purpura
- refers to the presence of varying sizes of hemorrhages in widespread areas of the skin and mucous membranes
d.
Hematoma
a tumor-like swelling or mass of blood confined to an organ, tissue, or space (common in head injuries)
e.
f.
Hematemesis
- vomiting of blood
- blood is generally dark and acid
- of gastric origin
Hemoptysis
- blood in the sputum arising from the oral cavity, larynx, trachea, bronchi, or lungs
- blood is bright red
g.
Epistaxis
- bleeding from the nose
h.
Melena
- from the greek word for “black”
- dark, tarry feces or vomit
- result of the action of gastro-intestinal secretions upon blood in the digestive tract
i.
j.
Hematuria
Exsanguination
- the loss of blood to the point where life can no longer be sustained
- blood in the urine
- an important sign in tumors of the urinary system
G. Postmortem Conditions of Disturbances in Circulation
1. Diminished circulation
2. Abscesses
3. Hemorrhage
4. Emaciation
5. Dehydration
6. Rapid decomposition
7. Discoloration
Exam
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