Hypoplasia (; adjective form ''hypoplastic'') is underdevelopment or incomplete development of a tissue or organ.Definition: hypoplasia
Dictionary of Cell and Molecular Biology (11 March 2008) Although the term is not always used precisely, it properly refers to an inadequate or below-normal number of cells.Hypoplasia
Stedman's Medical Dictionary. lww.com Hypoplasia is similar to aplasia, but less severe. It is technically ''not'' the opposite of hyperplasia (too many cells). Hypoplasia is a congenital condition, while hyperplasia generally refers to excessive cell growth later in life. (

Atrophy Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), malnutrition, poor nourishment, poor circulatory system, circulation, loss of hormone, ...

, the wasting away of already existing cells, is technically the direct opposite of both hyperplasia and hypertrophy.) Hypoplasia can be present in any tissue or organ. It is descriptive of many medical conditions, including underdevelopment of organs such as: *

Breasts The breasts are two prominences located on the upper ventral region of the torso among humans and other primates. Both sexes develop breasts from the same embryology, embryological tissues. The relative size and development of the breasts is ...

during

puberty Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a female, the testicles i ...

* Testes in Klinefelter's syndrome *

Ovaries The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are endocr ...

in Fanconi anemia, gonadal dysgenesis,

trisomy X Trisomy X, also known as triple X syndrome and characterized by the karyotype 47,XXX, is a chromosome disorder in which a female has an extra copy of the X chromosome. It is relatively common and occurs in 1 in 1,000 females, but is rarely diagn ...

Thymus The thymus (: thymuses or thymi) is a specialized primary lymphoid organ of the immune system. Within the thymus, T cells mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. The thymus ...

in DiGeorge syndrome * Labia majora in popliteal pterygium syndrome * Corpus callosum, connecting the two sides of the brain, in agenesis of the corpus callosum * Cerebellum caused by mutation in the reelin gene *

Tooth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tea ...

caused by oral pathology, such as Turner's hypoplasia * Chambers of the

heart The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...

in hypoplastic left heart syndrome and hypoplastic right heart syndrome * Optic nerve in optic nerve hypoplasia * Sacrum in sacral agenesis * Facial muscle in asymmetric crying facies * Thumb from

birth Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...

* Lungs, often as a result of oligohydramnios during gestation or the existence of congenital diaphragmatic hernia * Small bowel in coeliac disease *

Finger A finger is a prominent digit (anatomy), digit on the forelimbs of most tetrapod vertebrate animals, especially those with prehensile extremities (i.e. hands) such as humans and other primates. Most tetrapods have five digits (dactyly, pentadact ...

s and ears in harlequin-type ichthyosis *

Mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

in congenital hypothyroidism

References

{{reflist Medical terminology Anatomical pathology

See also

References