1. REVERSIBLE CELL INJURY
 By
Libason Hosea
MD2 student Muhimbili university
e mail: hlibason@gmail.com

2. REVERSIBLE CELL INJURY
(non lethal cell injury)
ADAPTIVE RESPONSE TO NOXIOUS STIMULI OR STRESS TO A
CELL INCLUDES;
-HYPERTROPHY
-HYPERPLASIA
-METAPLASIA
-ATROPHY
IF THE STIMULUS PERSISTS OR IF IT IS SEVERE FROM THE
BEGINNING,
THEN WHAT FOLLOWS IS CELL INJURY

3. Reversible cell injury
 injury follows after adaptive capability of the cell is
exceeded and there is severe membrane damage and
nuclear alteration.
1. Reversible cell injury
2. Irreversible cell injury

4. Causes of cell injury
1. Hypoxia
2. Ischemia
3. Chemical agents eg reactive oxygen species
4. Infectious agents
5. Immunologic reaction eg.autoimmune disease
6. Nutritional imbalances
7. Genetic defects eg. Hbs causing premature death of RBCs
8. Physical agents eg. Radiations, extrem temperatures, etc.
9. Aging
10. Nutritional imbalances ie.
 undernutrition eg kwarshiorkor and marasmus
 Overnutrition eg. Artherosclerosis

5. Morphologic alterations of cell injury
 Cellular swelling
 Fatty change
 Other changes

6. Cellular swelling
 Is the result of failure of energy dependent ion
pumps in plasma membrane leading to inability to
maintain ionic and fluid homeostasis
 Cellular swellings are difficult to see in light
microscope
 Microscopic examination may reveal small clear
vacuole within the cytoplasm
 These represents pinched off segment of ER

7. 2.Fatty change
 Occurs in hypoxic injury and various forms of toxic
or metaplastic injury
 Manifested by appearance of large or small lipid
vacuole in the cytoplasm
 Occur in cells involved and dependant on fat
metabolism such as hepatocytes and myocardial cells
 Injured cells may show increased esinophilic staining
which becomes much more pronounced with
progression to necrosis

8. 3.Other changes;
 Plasma cell membrane alterations
 Distortion of microvilli
 Mitochondrial changes such as mitochondrial
swelling
 Dilatation of ER
 Nuclear alteratins
 Eosinophilia alterations

9. if the the stimuli persists
 Irreversible cell injury
 Necrosis

10. Thank you
REFERENCE:CHAPTER 1, ROBBINS BASIC
PATHOLOGY
8 TH E D
KUMAR ET AL