Tutorials > General Pathology

In degenerations there is an alteration in cellular elements (metabolic or enzymatic disturbance). Some changes are reversible, some if the insult lasts a  prolonged period are irreversible. Biochemical changes within a cell occur before morphological changes are visible.

Atrophy: acquired decrease in size of a portion of body, organ, tissues or individual cells.

Reduction in the size of the organ may be due to either decrease in a number of its structural units (cells) – numerical atrophy, or to the decrease in the size of the individual units – simple atrophy

Atrophy may be unaccompanied by other degenerative changes. Often fuctional parenchyma is more affected then connective tissue (relative increase).

Fat tissue replacement (pancreatic, renal tissue) – numeral atrophy

Increase pigment content (atrophied cardiac muscle) – simple atrophy

Almost all atrophy are due to changes in the nutrition and metabolism of involved cells.

Certain organs (tissues) normally undergo a reduction in size during the life time – e.g. thymus, ovarian and breast atrophy ….

General atrophy involving widespread and numerous tissue of the body

• Atrophy of starvation – in condition of starvation from various reasons the body need to maintain especially structure and cells of the most essential organs (brain, heart, kidneys, adrenal, thyroid and pituitary glands and gonads – less atrophy relative to total body wasting), whereas the liver, spleen, lymphoid tissues and fatty stores show greater wasting
• Senil atrophy – present in variable degree in many organs and tissues in advanced age

Local atrophy:

• Disuse atrophy – result of inactivity of an organ or tissue (e.g. : neurotrophic atrophy – inactivity of muscle due to loss of motor nerve supply followed by its atrophy)
• Pressure atrophy – result of prolonged pressure upon a local area or group of cells (pressure from growing tumor, amyloid depositions, hydronephrosis – obstruction of ureter)
• Endocrine atrophy – occurs in organs that are dependent on endocrine stimulation (breasts after menopause)
• Toxis atrophy – result of toxic influence