General Pathology final
Disturbances of Growth
Congenital Anomalies
Agnesia: complete absence of an organ.
Aplasia: complete failure of development of an organ. It is represented by fibrous tissue.
Hypoplasia: Failure of an organ to reach the full adult size.
Atrophy
Definition: decrease in size and weight of organ or tissue due to decrease in size and / or number of its cells. Atrophic cells are usually replaced by firbous tissue, less commonly by fatty tissue.
Types of atrophy:
Physiologic Atrophy: **Atrophy of thymus gland after puberty. **Atrophy of ovaries and breast after menopause.
Pathologic Atrophy:
Generalized Atrophy: affects all organs and tissues [elastic tissue = wrinkled skin; bone = fragile; muscle = wasting; heart = brown atrophy].
• Increased catabolism in chronic diseases [tuberculosis], in thyro-toxicosis and in late stages of malignancy.
• Chronic malnutrition and chronic starvation.
• Senile atrophy in old age.
Localized Atrophy:
1. Disuse atrophy: due to diminshed function, e.g.
Atrophy of limb muscle after prolonged immobilization [bone fracture].
Atrophy of renal tubules after fibrosis of the corresponding glomerulus.
2. Pressure atrophy: due to continued pressure on tissues with decrease of its blood supply, e.g.
Atrophy of vertebral bodies opposite aortic aneurysm [intervertebral discs don’t atrophy to same extent = avascular].
Atrophy of liver cells after deposition of amyloid in the wall of sinusoids.
3. Vascular =Ischaemic atrophy: due to chronic ischaemia, e.g.
Atrophy of heart muscles after coronary atheroscolerosis.
4. Neuropathic atrophy: due to loss of neurotrophic impulses, e.g.
Atrophy of limb muscle after paralysis [poliomyelitis].
5. Endocrine atrophy: due to cut of hormone upon which organ depends e.g. Atrophy of female genitals and breast after removal of both ovaries.
Hypertrophy
Definition: increase in size and weight of organ or tissue due to increase in size of its cells. It
Congenital Anomalies
Agnesia: complete absence of an organ.
Aplasia: complete failure of development of an organ. It is represented by fibrous tissue.
Hypoplasia: Failure of an organ to reach the full adult size.
Atrophy
Definition: decrease in size and weight of organ or tissue due to decrease in size and / or number of its cells. Atrophic cells are usually replaced by firbous tissue, less commonly by fatty tissue.
Types of atrophy:
Physiologic Atrophy: **Atrophy of thymus gland after puberty. **Atrophy of ovaries and breast after menopause.
Pathologic Atrophy:
Generalized Atrophy: affects all organs and tissues [elastic tissue = wrinkled skin; bone = fragile; muscle = wasting; heart = brown atrophy].
• Increased catabolism in chronic diseases [tuberculosis], in thyro-toxicosis and in late stages of malignancy.
• Chronic malnutrition and chronic starvation.
• Senile atrophy in old age.
Localized Atrophy:
1. Disuse atrophy: due to diminshed function, e.g.
Atrophy of limb muscle after prolonged immobilization [bone fracture].
Atrophy of renal tubules after fibrosis of the corresponding glomerulus.
2. Pressure atrophy: due to continued pressure on tissues with decrease of its blood supply, e.g.
Atrophy of vertebral bodies opposite aortic aneurysm [intervertebral discs don’t atrophy to same extent = avascular].
Atrophy of liver cells after deposition of amyloid in the wall of sinusoids.
3. Vascular =Ischaemic atrophy: due to chronic ischaemia, e.g.
Atrophy of heart muscles after coronary atheroscolerosis.
4. Neuropathic atrophy: due to loss of neurotrophic impulses, e.g.
Atrophy of limb muscle after paralysis [poliomyelitis].
5. Endocrine atrophy: due to cut of hormone upon which organ depends e.g. Atrophy of female genitals and breast after removal of both ovaries.
Hypertrophy
Definition: increase in size and weight of organ or tissue due to increase in size of its cells. It