PATHO Flashcards
TISSUE ALTERATIONS IN ACUTE
INFLAMMATION
Vascular Changes and Cellular Changes
He was the first to describe vascular
changes in 1877.
Julius Cohnheim
VASCULAR CHANGES
- Changes in the Blood Vessels
- Changes in the Rate of Flow
- Changes in the Bloodstream
- Exudation of Plasma
- Emigration of Leukocytes
- Diapedesis of Erythrocytes
Immediately upon application of the irritant, the arterioles are constricted. The constriction is very short-lived (seconds), and is therefore of not much
importance.
Momentary constriction
The momentary constriction of vessels is quickly followed by their dilation that
involves first arterioles and then results in the opening of new capillary beds in the
area.
Vasodilation
Vasodilation leads to ________ and increased blood flow, the cause of heat
and redness.
hyperaemia
This results in concentration of red cells in small vessels and increased viscosity of the blood.
CHANGES IN THE RATE OF FLOW
Dilated small vessels packed with red cells
Stasis
The endothelial wall of capillaries and venules forms a semi-permeable barrier that allows free movement of
water and small molecules, and is only slightly permeable to plasma proteins.
Increased vascular permeability (vascular leakage):
Plasma proteins, namely, ________, ________, ________ leave the leaky vessels.
Albumin, globulins, fibrinogen
Together with the increased hydrostatic pressure due to vasodilation, they cause a marked outflow of fluid
and its accumulation in the interstitial tissue. This net increase of extravascular fluid is called ___________.
Inflammatory
oedema.
As the early vasodilation results in increased blood flow, later it is soon followed by this.
Slowing of the circulation
Retardation is achieved in four ways:
(i) by increasing the capillary bed in the area.
(ii) by swelling of the endothelial cells lining the capillaries.
(iii) increases viscosity of blood, and this leads to further retardation of the flow,
(iv) margination of the leukocytes.
The main change consists of a redistribution of the cellular elements of the bloodstream.
CHANGES IN THE BLOODSTREAM
Held in the centeR by the centripetal force of the flowing blood.
Cellular elements
External to the axial stream, a clear zone consisting mainly of plasma, which is
in contact with the wall of the vessel.
plasmatic stream
Process of leukocyte adhesion at the periphery of vessels
Margination
Process of brief, loose sticking of leukocytes to the endothelium
rolling
Firm sticking of leukocytes to the endothelium
adhesion
the endothelium is virtually lined by white cells.
pavementing
Following increased vascular permeability, fluid part of the blood escapes into the inflamed area.
EXUDATION OF PLASMA
This is the process by which leukocytes come out of the blood vessels into the extravascular space.
EMIGRATION OF LEUKOCYTES
refers to the process by which leukocyte migrate from blood vessels. AKA emigration
Diapedesis
4 SPECIFIC ACTIONS OF WBCS IN
INFLAMMATION
- Margination and pavementing
- Diapedesis
- Chemotaxis
- Phagocytosis
Is the process by which leukocytes are directed to the site of injury
CHEMOTAXIS
The process of taking particulate matter in the cytoplasm by cells
phagocytosis
5 groups of cells associated with phagocytosis
- Neutrophils
- Macrophages
- Capillary endothelial cells
- Simple squamous EC on serous surfaces
- Septal cells of the lung
Is the migration of cellular and humoral substances into an area of
inflammation
EXUDATION
Is composed of the cellular and humoral substances which accumulate in
an area of inflammation
EXUDATES
5 MAJOR COMPONENTS OF
EXUDATE
- the irritant
- injured tissue cells
- leukocytes (also macrophages and plasma cells)
- Plasma constituents (water, protein, fibrin, and antibodies)
- erythrocytes.
FACTORS THAT INFLUENCE
VARIATIONS IN THE APPEARANCE OF
AN AREA OF INFLAMMATION
- Nature of irritant
- Tissue involved
- Duration of the applicant of the irritant
When the principal constituent of the exudate is lymph or plasma
Serous
When the principal constituent of the exudate is mucin
Mucous or Cattarhal
When the principal constituent of exudate is fibrin
Fibrinous
When the principal constituent of the exudate are neutrophils
Suppurative
When the principal constituent of the exudate are RBCs
Hemorrhagic
When the principal constituent of the exudate are lymphocytes
Lymphocytic
Is the reaction of the body to a protein to which it has been previously
sensitized
Allergic
CLASSIFICATION OF INFLAMMATION
ACCORDING TO DURATION
Peracute
Acute
Subacute
Chronic
The process whereby the body destroys and remove the irritant and returns the part to as near a normal functional state
Healing
In the process of healing, destroyed cells may be replaced by cells of their own kind
repair by regeneration
Often healing is accomplished by replacing highly specialized cells with less
specialized connective tissues
repair by substitution
Factors affecting the
ability to achieve healing:
- The Genera, Family
- The Tissue or Organ involved
- The degree of specialization of the cell
- The age of the animal
Healing is by proliferation of parenchymatous cells leading to complete restoration of the original tissue
Regeneration
Repair is the replacement of injured tissue by
proliferation of fibrous tissue
Repair
Factors Inhibiting Repair
- Age
- Nutrition
- Immune depression
- Certain diseases
- Malignancy
- Drugs
- Superimposed infection
- Inflammatory damage
Untoward effects of
inflammation and repair
- Perforation
- Advancing planes of inflammatory tissue
- Extensive Fibrosis
- Complications that results from a sequelae
The fibers shrink, and the resultant tissue
scar or cicatrix
Known as healing by primary union or healing by first intention
Healing of a closed
wound
Known as healing by second intention or healing by granulation
Healing of an open wound
This is accomplished in the same manner as in the healing of open wounds
Healing of an abscess
This occurs by organization of exudates
Healing of serous membranes
Is characterized by a disturbance in metabolism by an elevation of the body temperature and by various functional disturbances such as increased pulse rate, anorexia, nausea, vomiting, constipation, increased thirst, scanty urine and dehydration.
Fever
Is the growth of new cells that proliferate
without control, serves no useful function, and has no orderly arrangement
Neoplasm
the science that deals with the
study of neoplastic growth
Oncology
Two kinds of Neoplasm
Benign and Malignant
Factors that indicate
the degree of anaplasia
- Enlargement of the nucleus
- multiple nuclei in the cell
- enlargement of the nucleolus
- increased number of mitotic figures
- hyperchromasia of the cell
- embryonal self type
Most common method of spread of
malignant cells
Infiltration
Spread of tumor cells from one organ to another by way of lymphatics blood vessels as an embolus
Metastasis
Transfer of tumor cells from
one serous or mucous surface to another by direct contact
Implantation /
Transplantation
Tumors derived from epithelial surfaces, either squamous or glandular.
Epithelial
involves an epithelial surface.
Papilloma
involves glandular epithelium
Adenoma
involves either squamous or glandular epithelium.
Carcinoma
Tumours derived from connective tissue in general (fibrous tissue, cartilage, bone,
muscle).
Non-epithelial
This tumour arises from an embryonic defect in growth and is composed of one germ layer only, the ectoderm, and contains teeth, hair, and other dermal structures.
Dermal cyst tumour
This tumour also arises from an embryonic defect in growth and is composed of two or
more germ layers.
Teratoma
