Practical 4: Inflammation Flashcards
What is inflammation
A process by which the body attempts to deal with injury to the tissues
Such damage may be caused by a variety of physical, chemical or biological agents
In the inflammatory response the body attempts to eliminate or neutralise injurious agents and repair the tissues
What are three diseases whereby acute inflammation takes place
Gastric ulcer
Bacterial pneumonia
Appendix with acute inflammation
What is acute inflammation
The initial series of events following injury to a tissue, directed towards neutralizing the injurious agents and restoring the tissues to useful function
Cells involved are the neutrophil
What does the outcome of acute inflammation depend on?
(3)
The degree of tissue damage
The nature of the injurious agent
The type of tissue involved
What are three tissue responses to acute inflammation
Resolution
Organisation and repair
Inflammatory exudate
What is resolution
When tissue damage is minimal, the exudate is reabsorbed into local vessels and no evidence of injury remains
What is organisation and repair
Where tissue damage is more extensive.
In this process the dead tissue is phagocytosed and the necrotic area is replaced with granulation tissue composed of a vascularised connective tissue laid down by fibroblasts
The capillaries disappear when fibrous repair is complete with the formation of scar tissue at the site of the original tissue destruction
What is organisation and repair
Where tissue damage is more extensive.
In this process the dead tissue is phagocytosed and the necrotic area is replaced with granulation tissue composed of a vascularised connective tissue laid down by fibroblasts
The capillaries disappear when fibrous repair is complete with the formation of scar tissue at the site of the original tissue destruction
What is inflammatory exudate
Composed of serum, leucocytes (mostly PMLs? and fibrin
What is chronic inflammation
(3)
Results from persistence of injurious stimulus over a long period of time causing continuing tissue damage
It most commonly follows acute inflammation where the process has failed to eradicate the causative agent
Areas of acute inflammation may persist in chronic inflammation
What is chronic inflammation
(3)
Results from persistence of injurious stimulus over a long period of time causing continuing tissue damage
It most commonly follows acute inflammation where the process has failed to eradicate the causative agent
Areas of acute inflammation may persist in chronic inflammation
What are some features of chronic inflammation
Change in cellular infiltrate: to consist of lymphocytes and plasma cells
Stromal changes: due to deposition of connective tissue components (scar formation)
Formation of granulomas
What are granulomas
(2)
An organised collection of inflammatory cells including activated macrophages (epitheliod histiocytes), Langhand’s giant cells (multinucleated macrophages) and lymphocytes
Granulomas are associated with M. tuberculosis infections where organism is resistant to destruction by neutrophils and fail to excite a strong acute reaction
Define exudate
Acute inflammation exudate can be:
- purulent: Neutrophils dominate
- Fibrinous: fibrin abundant
- Serous: fluid is major component
Define granulation tissue
(2)
When tissue damage is extensive, the exudate undergoes a process called organisation and repair
In this process the dead tissue is phagocytosed and the necrotic area is replaced with granulation tissue composed of a vascularised connective tissue laid down by fibroblasts
Define hyperaemia
An increase in the amount of blood in the tissue
Typically seen in acute inflammation due to the release of histamine which stimulated blood flow to the area
Define granuloma
Some microorganisms are resistant to destruction by neutrophils and
fail to excite a strong acute reaction. The initial neutrophil response is usually sparse
and is quickly followed by a macrophage response. This local accumulation of
macrophages produces a discrete lesion called a granuloma
Define giant cell
(2)
Activated macrophages enlarge and sometimes fuse to form multinucleated giant cells (Langhan’s giant cells)
Seen at the edge of the granuloma
Write about the normal mucosa of the stomach
(3)
Simple columnar cells -> a single layer of columnar cells attached to the basement membrane, with oval-shaped nuclei located in the basal region
Epithelium is towards the top of the mucosal layer of the stomach
Mucosa of the stomach contains many other types of secretory cells
Write about the normal mucosa of the stomach
(3)
Simple columnar cells -> a single layer of columnar cells attached to the basement membrane, with oval-shaped nuclei located in the basal region
Epithelium is towards the top of the mucosal layer of the stomach
Mucosa of the stomach contains many other types of secretory cells
Write about gastric ulcers
Acute inflammation
Granulation tissue, fibrous area, cellular exudate all seen
Area closest to lumen affected first
May be able to see some blood
Should be able to see some neutrophils
Blue staining fibrous layer
May see granulation tissue/scarring
Gastric flare up is acute
Striated bands = scarring tissue
May be able to see neutrophil migration in the capillaries
What may cause ulcers?
(7)
Smoking
Bad diet
Alcohol
Hereditary causes
High acid erodes mucosa to form ulcers
NSAIs -> non-steroidal anti-inflammatory drugs also causes ulcers
It may heal, could become chronic, could form a perforation which is life threatening -> cause must be treated in order to heal
Write about pneumonia
(3)
Hyperaemia -> blood in alveolar wall
Thickened alveolar walls
Usually sick for three weeks but inflammation is always neutrophilic/acute. This is strange for disease
Should still be able to tell its lung tissue
Give three examples of acute infections which last longer than 3 days
Ulcerative colitis and gastric ulcers also remain as acute inflammation
Pneumonia
Write about the appendix
(9)
Start of large intestine
Part of lymphoid system
Can become inflamed in some people
Inflammatory cells are found in normal tissue
Screens samples of matter from intestine
Appendicitis is a neutrophilic response
Architecture is destroyed
Appendix can’t recover
Usually bacteria causes an infection
If chronically inflammed it is at risk of bursting -> usually doesn’t get the chance to do this
What are four examples of chronic inflammation
PCP pneumonia
Hashimoto’s thyroiditis
Cervicitis
Tuberculosis in the lung
What is PCP pneumonia
(3)
Fungal pneumonia caused by pneumocystis jirovecii
Only seen in immunocompromised patients e.g. HIV patients or cancer patients or those on immunosuppressents
Life threatening infection -> immediate hospitalisation
Forms foamy mass in airspace
Grocotts methenamine silver
What is cervicitis?
(6)
Stratified squamous epithelium in normal
Disease = blue staining lymphocytes
Mucosa changes to glandular
Groups of lymphocytes will be seen
Caused by infections (Not HPV) but could be candida infection that hasn’t cleared
Will see lots of plasma cells
What is TB?
Destroys normal lung tissue
Round structures form granulomas
Doesn’t look like lung tissue
Casesous necrosis
Granulomas called tubercles
Langhan’s Giant cells
Flat macrophages at outside of granuloma (pathognomic cells)
ZN stain for TB
