Atrophy: Types and Causes

Questions and Answers

What characterizes physiological atrophy?

It affects only a single organ.

It is always caused by disease.

It occurs as a normal developmental process. (correct)

It leads to increased cell number.

Which type of atrophy occurs due to long-term disease processes?

General pathological atrophy (correct)

Physiological atrophy

Localized atrophy

Disuse atrophy

Which of the following is an example of vascular atrophy?

Atrophy of thigh muscles due to prolonged bed rest

Atrophy of muscles due to nerve damage

Atrophy of the thymus after puberty

Atrophy of heart muscles due to diminished blood supply (correct)

What is the primary mechanism behind hypertrophy?

Increased cell size due to protein synthesis Signup and view all the answers

What is localized atrophy due to decreased function called?

Disuse atrophy Signup and view all the answers

Which of these factors is associated with pathological atrophy?

Aging Signup and view all the answers

What type of hypertrophy involves an increase due to hormone stimulation?

Physiological hypertrophy Signup and view all the answers

What typically causes neuropathic atrophy?

Loss of neurotropic impulses Signup and view all the answers

Study Notes

Atrophy

Atrophy refers to the reduction in size of a tissue, organ, or cell after its full development.
Atrophic cells may be replaced by fibrous or, in rare cases, fatty tissue.

Types of Atrophy

Physiological Atrophy:
- Normal developmental process leading to size decrease.
- General Atrophy: Affects all organs; associated with aging (e.g., senile atrophy results in wrinkled skin due to loss of elastic fibers).
- Localized Atrophy: Specific organs affected, such as thymus post-puberty or ovaries and breasts after menopause.
Pathological Atrophy:
- General Atrophy:
  - Caused by increased catabolism in chronic diseases (e.g., tuberculosis, thyrotoxicosis).
  - Anabolism disruption leads to conditions like chronic malnutrition and starvation, where glycogen and fat decrease first, followed by muscle protein loss.
- Localized Atrophy:
  - Disuse Atrophy: Results from reduced function, such as muscle atrophy after prolonged immobilization.
  - Vascular Atrophy: Occurs from decreased blood supply, for instance, atherosclerosis affecting heart muscle.
  - Neuropathic Atrophy: Caused by loss of nerve impulses; examples include muscle atrophy due to poliomyelitis or severed motor nerves.
  - Endocrine Atrophy: Affects organs reliant on hormonal signals; excessive thyroxine may elevate metabolism rates, leading to atrophy.

Hypertrophy

Hypertrophy is the abnormal enlargement of a tissue or organ due to increased cell size, while cell number remains unchanged.
Result of enhanced protein synthesis to fulfill increased functional demands.

Types of Hypertrophy

Physiological Hypertrophy:
- Characterized by cell enlargement in normal contexts.
- Examples include uterine growth during pregnancy due to hormonal stimulation or muscle enlargement in bodybuilders.

Description

Explore the concept of atrophy, its definition, types, and causes. Understand how atrophy can occur physiologically and how it affects tissues and organs. Delve into the differences between general and other forms of atrophy.