Hyperplasia (or "hypergenesis") is a general term referring to the proliferation of cells within an organ or tissue beyond that which is ordinarily seen in e. g. constantly dividing cells. Hyperplasia may result in the gross enlargement of an organ, the formation of a benign tumor, or may be visible only under a microscope. See also Cancer A tumor or tumour is the name for a swelling or lesion formed by an abnormal growth of cells (termed neoplastic Histology (from the Greek = 'tissue' is the study of the microscopic anatomy of cells and tissues of Plants and Hyperplasia is considered to be a physiological response to a specific stimulus, and the cells of a hyperplastic growth remain subject to normal regulatory control mechanisms. Physiology (from Greek grc φύσις physis, "nature origin" and grc -λογία -logia) is the study of the mechanical physical This stands in contrast to neoplasia (the process underlying cancer and some benign tumors), in which genetically abnormal cells proliferate in a non-physiological manner which is unresponsive to normal stimuli. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled [1]
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Causes
Hyperplasia may be due to any number of causes, including increased demand, chronic inflammatory response, hormonal dysfunctions, or compensation for damage or disease elsewhere. Hyperplasia may be harmless and occur on a particular tissue. An example of a normal hyperplastic response would be the growth and multiplication of milk-secreting glandular cells in the breast as a response to pregnancy, thus preparing for future breast feeding. A gland is an organ in an animal's body that synthesizes a substance for release such as Hormones or Breast milk, often into the Bloodstream The breast is the upper Ventral region of an animal’s Torso, particularly that of Mammals including Human beings. Pregnancy ( Latin graviditas) is the carrying of one or more offspring known as a Fetus or Embryo, inside the Uterus of a Female Breastfeeding is the feeding of an Infant or young Child with Breast milk directly from human Breasts, not from a Baby bottle or other
Hyperplasia may also be induced artificially by injecting hormones such as IGF-1 and human growth hormone. Insulin-like growth factor 1 (IGF-1 that was once called somatomedin C is a Polypeptide Protein Hormone similar in Molecular structure Growth hormone ( GH) is a Peptide hormone that stimulates growth and cell reproduction in humans and other animals Perhaps the most interesting and potent effect IGF has on the human body is its ability to cause hyperplasia, which is an actual splitting of cells. Hypertrophy, on the other hand, is what occurs during weight training and steroid use and is simply an increase in the size of muscle cells. Hypertrophy is the increase of the size of an organ or in a select area of the tissue With IGF use, one is able to cause this hyperplasia which actually increases the number of muscle cells present in the tissue. Weight training with or without anabolic steroid use enables these new cells to mature in size and strength. Anabolic steroids, or anabolic-androgenic steroids ( AAS) are a class of Steroid hormones related to the hormone Testosterone. In addition, animal tests have shown that stretching a muscle can trigger hyperplasia, though this phenomenon has yet to be confirmed in humans. [2]
Hyperplasia may also occur abnormally, and is associated with a variety of clinical diseases.
Examples in human biology and disease
Some of the more commonly-known clinical forms of hyperplasia, or conditions leading to hyperplasia, are:
- Congenital adrenal hyperplasia
- Endometrial hyperplasia - Hyperproliferation of the endometrium, usually in response to unopposed estrogen stimulation in the setting of polycystic ovary syndrome or exogenous administration of hormones. Congenital adrenal hyperplasia ( CAH) refers to any of several Autosomal Recessive Diseases resulting from Mutations Endometrial hyperplasia is a condition of excessive proliferation of the cells of the Endometrium, or inner lining of the Uterus. Estrogens (US otherwise oestrogens or œstrogens) are a group of Steroid compounds named for their importance in the Estrous cycle, Polycystic ovary syndrome abbreviated PCOS or PCO (also known clinically as Stein-Leventhal syndrome, Sclerocystic ovary syndrome, Hyperthecosis Atypical endometrial hyperplasia may represent an early neoplastic process which can lead to endometrial adenocarcinoma. Endometrial cancer refers to several types of malignancy which arise from the Endometrium, or lining of the Uterus.
- Benign prostatic hyperplasia, also known as prostate enlargement. Benign prostatic hyperplasia ( BPH) also known as nodular hyperplasia, benign prostatic hypertrophy (technically a misnomer or benign enlargement of
- Hyperplasia of the breast - "Hyperplastic" lesions of the breast include usual ductal hyperplasia, a focal expansion of the number of cells in a terminal breast duct, and atypical ductal hyperplasia, in which a more abnormal pattern of growth is seen, and which is associated with an increased risk of developing breast cancer. The breast is the upper Ventral region of an animal’s Torso, particularly that of Mammals including Human beings. The biology of these lesions is the subject of dispute, with some authorities arguing that both of these lesions are the result of neoplasia, and that the application of the term "hyperplasia" in this instance is "inaccurate. "[3]
- Focal epithelial hyperplasia (also known as Heck's disease) - This is a wart-like growth in the mucous tissues of the mouth or, rarely, throat that is caused by certain sub-types of the human papillomavirus (HPV). A human papillomavirus ( HPV) is a Papillomavirus that infects the skin and Mucous membranes of Humans Approximately 130 HPV types have been Heck's disease has not been known to cause cancer.
- Sebaceous hyperplasia - In this condition, small yellowish growths develop on the skin, usually on the face. Sebaceous hyperplasia is a disorder of the Sebaceous glands in which they become enlarged This condition is neither contagious nor dangerous.
- Compensatory liver hyperplasia - The liver undergoes cellular division after acute injury, resulting in new cells that restore liver function back to baseline. The liver is a vital organ in the human body and is present in Vertebrates and some other animals Approximately 75% of the liver can be acutely damaged or resected with seemingly full regeneration through hepatocyte division, i. Hepatocytes make up 70-80% of the Cytoplasmic mass of the Liver. e. , hyperplasia. This is the basis for living-donor liver transplants.
References
- ^ Ramzi Cotran, Vinay Kumar, Tucker Collins (1999). Robbins Pathologic Basis of Disease, Sixth Edition. W. B. Saunders. ISBN 072167335X.
- ^ Antonio, J, et al. (1994) "Muscle fiber splitting in stretch-enlarged avian muscle". Medicine & Science in Sports & Exercise, 26:8, 973-7.
- ^ Tavassoli FA (2005). "Breast pathology: rationale for adopting the ductal intraepithelial neoplasia (DIN) classification". Nature clinical practice. Oncology 2 (3): 116-7. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 16264885.
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