Involution (medicine)

Involution (medicine)

Involution of an organ is the shrinking or return to a former size.

Contents

Examples

Thymus

The thymus continues to grow between birth and puberty and then begins to atrophy, a process directed by the high levels of circulating sex hormones. Proportional to thymic size, thymic activity (T cell output) is most active before puberty. Upon atrophy, the size and activity are dramatically reduced, and the organ is primarily replaced with fat. The atrophy is due to the increased circulating level of sex hormones, and chemical or physical castration of an adult results in the thymus increasing in size and activity. [1]

Uterus

Involution is the process by which the uterus is transformed from pregnant to non-pregnant state. It is a physiological process occurring after e.g. parturition; the hypertrophy of the uterus has to be undone since it does not need to house the fetus anymore. This process is primarily due the hormone oxytocin.

Mammary gland

During pregnancy until after birth, mammary glands grow steadily to a size required for optimal milk production. At the end of breastfeeding, the number of cells in the mammary gland becomes reduced until approximately the same number is reached as before the start of pregnancy.

References

  1. ^ Sutherland JS. Activation of thymic regeneration in mice and humans following androgen blockade. J Immunol 2005 15;175(4):2741-53

See also

Subinvolution


Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • involution form — n an irregular or atypical bacterium formed under unfavorable conditions (as in old cultures) * * * an abnormally shaped bacterial cell that occurs in an old culture or one that has been exposed to unfavorable conditions …   Medical dictionary

  • Involution — may refer to: * Involution (mathematics), a function that is its own inverse * Involution (medicine), the shrinking of an organ …   Wikipedia

  • Involution — A retrograde change. After treatment, a tumor may involute. With advancing age, there may be physical and emotional involution. * * * 1. Return of an enlarged organ to normal size. 2. Turning inward of the edges of a part. 3. In psychiatry,… …   Medical dictionary

  • senile involution — involution (def. 3) …   Medical dictionary

  • involution cyst — mammary duct ectasia …   Medical dictionary

  • Puerperium — The time immediately after the delivery of a baby. (In Latin a puerpera is a woman in childbirth since puer means child and parere means to give birth.) Puerperal fever is childbirth (or childbed) fever due to an infection usually of the… …   Medical dictionary

  • subinvolution — Arrest of the normal involution of the uterus following childbirth with the organ remaining abnormally large. * * * sub·in·vo·lu·tion .in və lü shən n partial or incomplete involution <subinvolution of the uterus> * * * n. failure of the… …   Medical dictionary

  • degeneration — 1. Deterioration; passing from a higher to a lower level or type. 2. A worsening of mental, physical, or moral qualities. 3. A retrogressive pathologic change in cells or tissues, in consequence of which their functions are often impaired or… …   Medical dictionary

  • involutional — Relating to involution. * * * in·vo·lu·tion·al .in və lüsh nəl, ən əl adj 1) of or relating to involutional melancholia <involutional depression> 2) of or relating to the climacterium and its associated bodily and psychic changes <the… …   Medical dictionary

  • Acne — Localized skin inflammation as a result of overactivity of the oil glands at the base of hair follicles. Acne happens when oil (sebaceous) glands come to life around puberty, when these glands are stimulated by male hormones that are produced in… …   Medical dictionary

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”