[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Histology](https://durgical.com/en/histology/) › [The cell](https://durgical.com/en/histology/#a-cell) › Cell adaptations: hypertrophy, hyperplasia, atrophy, metaplasia [Histology](https://durgical.com/en/histology/) · [The cell](https://durgical.com/en/histology/#a-cell) # Cell adaptations: hypertrophy, hyperplasia, atrophy, metaplasia - Process Under a sustained stimulus, cells grow, multiply, shrink or change type to survive. Updated 2026-11-01 **See it in 3D:** [Esophagus](https://durgical.com/en/anatomy/esophagus-abdominal-part/) · [Trachea](https://durgical.com/en/anatomy/trachea/) · [Cervix](https://durgical.com/en/anatomy/cervix-of-uterus/) ## Key points - Hypertrophy = bigger; hyperplasia = more cells; atrophy = fewer or smaller; metaplasia = another type. - Barrett: squamous → intestinal columnar with goblet cells; adenocarcinoma risk. - Smoker: ciliated columnar → squamous. - Metaplasia is reversible; dysplasia is the step before carcinoma. ## What it is Adaptations are reversible responses to a change in demand or to chronic injury. They can be normal (the uterus in pregnancy) or disease-driven (the heart in hypertension, Barrett oesophagus). Metaplasia protects in the short term but can become the ground for dysplasia and cancer. ## The adaptations to tell apart | Change | What happens | Physiological example | Pathological example | | --- | --- | --- | --- | | Hypertrophy | Cells get bigger | Skeletal muscle with training; uterus in pregnancy | Left ventricular hypertrophy from hypertension | | Hyperplasia | Cells increase in number | Breast at puberty and in lactation; liver regeneration | Endometrial hyperplasia from excess oestrogen; benign prostatic hyperplasia | | Atrophy | Cells get smaller or fewer | Involution of the thymus; uterus after menopause | Muscle from disuse or denervation; brain from chronic ischaemia | | [Metaplasia](https://durgical.com/en/conditions/gastro-oesophageal-reflux-disease/) | One adult cell type is replaced by another, tougher one | Squamous metaplasia of the cervical transformation zone | Barrett oesophagus; the smoker's bronchus | | [Dysplasia (not an adaptation)](https://durgical.com/en/conditions/cervical-cancer/) | Disordered growth with atypia, before cancer | None | Cervical intraepithelial neoplasia from HPV | ## Clinical notes - Barrett oesophagus: after chronic reflux, the stratified squamous epithelium of the distal oesophagus is replaced by intestinal-type columnar epithelium with goblet cells; the risk of oesophageal adenocarcinoma rises. - Smoker's bronchus: ciliated pseudostratified columnar epithelium turns squamous; it resists smoke but loses mucociliary clearance. - Adult cardiac myocytes barely divide, so the heart adapts by hypertrophy, not hyperplasia. - Vitamin A deficiency also causes squamous metaplasia (for example in the conjunctiva). ## In the lab - In a Barrett biopsy, goblet cells look like clear, mucus-filled cups between columnar cells; Alcian blue stains them blue. - Hyperplasia keeps normal architecture and normal-looking cells; dysplasia shows large, hyperchromatic nuclei and loss of maturation. ## Memory aid Changing uniform is not betrayal: metaplasia swaps cell type to survive; the betrayal starts with dysplasia. ## Test yourself Think of the answer, then tap the question to see it. ## What kind of metaplasia defines Barrett oesophagus? Replacement of stratified squamous epithelium by intestinal-type columnar epithelium with goblet cells. ## Why does the heart respond to overload with hypertrophy and not hyperplasia? Adult cardiac myocytes hardly divide; they can only get bigger. ## What change happens in a smoker's bronchial epithelium? Squamous metaplasia: ciliated columnar epithelium is replaced by squamous epithelium, which is tougher but does not clear mucus. ## What separates dysplasia from hyperplasia under the microscope? Dysplasia shows atypia (large, hyperchromatic nuclei) and disorder; hyperplasia keeps normal-looking cells. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/histology/cell-adaptations-hypertrophy-hyperplasia-atrophy-metaplasia/) ## See it in 3D The structures of Durgical's 3D anatomy where it is found. - [Esophagus](https://durgical.com/en/anatomy/esophagus-abdominal-part/) - [Trachea](https://durgical.com/en/anatomy/trachea/) - [Cervix](https://durgical.com/en/anatomy/cervix-of-uterus/) ## Related - [Cell injury, apoptosis and necrosis](https://durgical.com/en/histology/cell-injury-apoptosis-and-necrosis/) - [Cell cycle, mitosis and meiosis](https://durgical.com/en/histology/cell-cycle-mitosis-and-meiosis/) - [Esophagus and the Barrett change](https://durgical.com/en/histology/esophagus-and-the-barrett-change/) - [Simple, stratified, pseudostratified and transitional epithelium](https://durgical.com/en/histology/simple-stratified-pseudostratified-and-transitional-epithelium/) - [Cervix and vagina: the transformation zone](https://durgical.com/en/histology/cervix-and-vagina-the-transformation-zone/) ## Related conditions - [Gastro-oesophageal reflux disease (GERD)](https://durgical.com/en/conditions/gastro-oesophageal-reflux-disease/) - [Oesophageal cancer](https://durgical.com/en/conditions/oesophageal-cancer/) - [Cervical cancer](https://durgical.com/en/conditions/cervical-cancer/) - [Human papillomavirus (HPV) infection](https://durgical.com/en/conditions/human-papillomavirus-infection/) [← All of histology](https://durgical.com/en/histology/) Educational content on normal microscopic structure and its clinical relevance; no substitute for studying slides or for a health professional's advice. Sources: [What Is Cancer?](https://www.cancer.gov/about-cancer/understanding/what-is-cancer) (National Cancer Institute, 2021); [Barrett’s Esophagus](https://www.niddk.nih.gov/health-information/digestive-diseases/barretts-esophagus) (National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), 2020); [4.6 Tissue Injury and Aging](https://openstax.org/books/anatomy-and-physiology-2e/pages/4-6-tissue-injury-and-aging) (OpenStax (Rice University), 2022). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/histology/cell-adaptations-hypertrophy-hyperplasia-atrophy-metaplasia/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/histology/cell-adaptations-hypertrophy-hyperplasia-atrophy-metaplasia/