Aging - Tissue, Cell, Morphology

aging

Table of Contents

Introduction
Biological theories of aging
- Genetic theories
- Nongenetic theories
  - Wear-and-tear theory
  - Cross-linking theory
  - Autoimmune theory
  - theory
  - Oxidative damage theory
  - Psychosociological theory
Natural history of aging
- Reproduction and aging
- Species differences in longevity and aging
- The inheritance of longevity
Senescence in mammals
- Changes in body composition, metabolism, and activity
- Changes in structural tissues
- Tissue cell loss and replacement
- Mammalian cell cultures
- Changes in tissue and cell morphology
Aging at the molecular and cellular levels
- Aging of genetic information systems
- Aging of the immune system
- Aging of neural and endocrine systems
Internal and external causes of aging
- External environmental agents
  - Ionizing radiation
  - Temperature
  - Physical wear of nonrenewable structures
  - Infectious disease and nutrition
- Internal environment: consequences of metabolism
Anti-aging and longevity research
- Antioxidants
- Calorie restriction and longevity
- Sirtuins
- Rapamycin
- Stem cells
- Genetics and life span

References & Edit History Quick Facts & Related Topics

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aging summary

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There are numerous instances of tissue changes with age. The atrophy of tissues of moderate degree is usual. The shrinkage of the thymus is especially striking and important in view of its role in immunological defense. The diminution of cellular tissue and replacement by fatty or connective tissue is prominent in bone marrow and skin. In the kidney, entire secretory structures (nephrons) are lost. The secretory cells of the pancreas, thyroid, and similar organs decrease in numbers. In addition, connective tissues change, becoming increasingly stiff. This makes the organs, blood vessels, and airways more rigid. Cell membranes also change, and ...(100 of 9184 words)

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