Chapter 4 – Anatomical Adaptation to Puberty, Pregnancy and Menopause




Abstract




Puberty refers to the transition period from childhood to adulthood.





Chapter 4 Anatomical Adaptation to Puberty, Pregnancy and Menopause



Swati Tiwari



1 Puberty




  • Puberty refers to the transition period from childhood to adulthood.



  • It begins at around 10–11 years of age in girls. It is completed by 15–17 years when Women attain sexual maturity.



  • It begins under the influence of hormonal signalling to the ovaries in Women (gonads in males).



  • This stimulates libido and the growth, function and transformation of the brain, bones, muscle, blood, skin, hair, breasts and sexual organs.



2 Menopause




  • Menopause refers to the permanent cessation of menstruation as a result of loss of ovarian follicular activity.



  • Climacteric refers to the period of time on either side of menopause, during which the female passes from the reproductive to non-reproductive stage (about 5–10 years).



  • Age of menopause:




    1. ◦ Genetically predetermined.



    2. ◦ Occurs around 45–55 years of age; the average being 50 years



    3. ◦ Cigarette smoking, severe malnutrition and thin body habitus predispose to early menopause.



    4. ◦ Clinical relevance: due to today’s longer lifespan, Women spend considerable time in estrogen deprivation, causing long-term symptomatic and metabolic complications.




  • Important symptoms of menopause:




    1. ◦ Cessation of menstruation.



    2. ◦ Urogenital atrophy.



    3. ◦ Osteoporosis and fracture.



    4. ◦ Cardiovascular disease.



    5. ◦ Psychological changes.



    6. ◦ Vasomotor symptoms: hot flushes (cutaneous vasodilation and perspiration).



    7. ◦ Sexual dysfunction.



    8. ◦ Skin and hair: loss of collagen, thinner skin.



    9. ◦ Dementia and cognitive decline.




3 Mammary Glands



3.1 Newborn




  • Newborn breasts contain lactiferous ducts, but no alveoli.



  • Witch’s milk: some secretions may occur from newborn breasts under the influence of maternal hormones that cross the placenta and enter the fetal circulation.



3.2 Puberty





  1. 1. Thelarche is defined as development of breast. It is characterised by the following:




    1. ◦ First noticeable sign of puberty, and occurs anywhere between 10 and 16 years of age (peak time: 13 years of age).



    2. ◦ Occurs under the influence of increase in sex steroids.



    3. ◦ Increase in adipose tissue content.



    4. ◦ Inactive gland with sparse glandular component.



    5. ◦ Proliferation of duct system.



    6. ◦ Terminal part of ducts has polyhedral cells but very few alveoli are seen at this stage.



Table 4.1 describes the Tanner stages of development.




  1. 2. Pubarche:




    1. ◦ Pubarche is the growth of pubic and underarm hair, oil and sweat glands, especially in the axilla).




  2. 3. Menarche:




    1. ◦ Menarche is the onset of first menstrual period.



    2. ◦ Blind girls have late menarche.



    3. ◦ Cyclic changes begin in the mammary gland.



    4. ◦ In the follicular phase (estrogen influence): intralobular stroma is less dense. Terminal ductules appear as cords lined by cuboidal cells. There is little or no lumen.



    5. ◦ In the luteal phase (progesterone influence): lining epithelial cells are taller. Small amounts of secretions appear in the lumen. Oedematous intralobular stroma. Women perceive tenderness and increase in breast tissue mass.



    6. ◦ Last few days of menstrual cycle: there is involution and apoptosis.





Table 4.1 The Tanner stages of breast development in girls





















Stage I Elevation of papilla
Stage II Breast bud and papilla elevated, enlargement of sides of areola (around 9.8 years)
Stage III Enlargement of entire breast tissue
Stage IV Secondary mound of areola and papilla projecting above breast (12.1 years)
Stage V Areola recessed to general contour of breast


3.3 Pregnancy


Serial changes in the breast during pregnancy are described in Table 4.2.




Table 4.2 Breast changes during pregnancy















First trimester


  • Elongation and branching of terminal ductules



  • Proliferation and differentiation of lining epithelial cells



  • Hyperpigmented areola, appearance of Montgomery tubercles and secondary areola

Second trimester Differentiation of alveoli lined by flat to low columnar cells
Third trimester


  • Maturation of alveoli: lining epithelium becomes cuboidal



  • Cells develop extensive rough endoplasmic reticulum (rER) with lipid droplets



  • Hypertrophy of secretory cells



  • Accumulation of secretions in alveoli



3.3.1 Lactation



  • During lactation, milk is produced by the epithelial cells of the alveoli and accumulates in their lumens and inside the lactiferous ducts.



  • Colostrum: in the first two or three days after birth, a protein-rich thick fluid called colostrum is secreted. This high-protein secretion, rich in vitamin A, sodium and chloride also contains lymphocytes and monocytes, minerals and lactalbumin. It contains less fat and more protein than regular milk and is rich in antibodies (predominantly secretory immunoglobulin A (IgA)), which provide some degree of passive immunity to the newborn, especially within the gut lumen.



  • Milk: usually produced by the fourth day after parturition, this is a fluid that contains minerals, electrolytes, carbohydrates (including lactose), immunoglobulins (mostly IgA), proteins (including caseins) and lipids.

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Related posts:

  1. Chapter 3 – Anatomy of the Pelvis in Obstetrics
  2. Chapter 5 – Anatomy of the Endocrine Glands: Thyroid and Pituitary
  3. Chapter 10 – Gametes and Fertilisation
  4. Chapter 17 – Physiology of Wound Healing

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Dec 29, 2020 | Posted by in GYNECOLOGY | Comments Off on Chapter 4 – Anatomical Adaptation to Puberty, Pregnancy and Menopause

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