MEDICAL BIOLOGY, HUMAN ANATOMY, PHYSIOLOGY AND PATHOLOGY - Ya.I. Fedoniuk 2010

BIOLOGY

SECTION 1. BIOLOGICAL BASES OF HUMAN VITAL ACTIVITY

1.4. ONTOGENETIC LEVEL OF LIFE ORGANIZATION

1.4.3. Biology of Individual Development

Neurohumoral Regulation of GROWTH AND DEVELOPMENT Processes

Growth is regulated by Growth Hormone—somatotropic hormone (STH or somatotropin)—which is produced by the anterior lobe of the Pituitary Gland. Hypofunction of the anterior pituitary in childhood leads to Pituitary dwarfism (nanism), while body proportions remain intact. Decreased STH synthesis leads to sexual underdevelopment. Such dwarfs retain child-like facial features and have underdeveloped secondary sexual characteristics. Hypersecretion of the anterior pituitary leads to excessive height—gigantism (over 2 meters in men). The cessation of somatotropic hormone secretion coincides with Puberty. However, if this hormone continues to be secreted in adulthood, acromegaly is observed—a pathological growth of certain body parts (enlargement of the BONES OF THE hands, feet, and facial Skeleton).

Normal growth and development also require THYROID Hormones—thyroxine and triiodothyronine. In humans, insufficient thyroid function in childhood leads to cretinism, which is characterized by mental retardation, delayed growth and sexual development, and impaired body proportions (tubular bones are short and thick).

The Gonads produce a range of Sex Hormones (both male and female). Male Sex Hormones (androgens, primarily testosterone) are synthesized in the interstitial Cells of the Testes. They ensure The Development of secondary sexual characteristics and regulate the reproductive function of the male body (Spermatogenesis). Female Sex Hormones (estrogens, progestins) are produced in the ovarian follicles; they drive the development of secondary sexual characteristics and participate in the realization of the female reproductive function (facilitating Fertilization, embryonic development, and the normal course of Pregnancy and Childbirth).



Last update: 08/08/2026

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