Anatomy and Physiology of Children and Adolescents - M. R. Sapin 2007

Endocrine System
Classification, structure, and functions of endocrine glands

The human Endocrine glands are small in size and richly supplied with Blood Vessels. Blood delivers the necessary "building Materials" to them and carries away Hormones. Fibers of the Autonomic Nervous system also innervate the endocrine glands.

Endocrine glands, as well as isolated endocrine Cells scattered across various Organs and Tissues, vary in origin and Structure. However, they all play a vital role in metabolic processes and the humoral regulation of life-sustaining Functions. Consequently, these glands are functionally integrated into a unified Endocrine System (Fig. 77).

Endocrine glands are classified into pituitary-dependent and pituitary-independent glands. Pituitary-dependent glands include The Thyroid Gland, the adrenal cortex, and the Gonads. Pituitary-independent glands comprise the Parathyroid glands, the pancreatic islets (islets of Langerhans), The adrenal medulla, and Paraganglia. The endocrine system also includes the Pineal Gland (epiphysis) and Solitary Hormone-Producing Cells (the Cytology/cytology/65.html">Diffuse endocrine system).



Last update: 10/08/2026

Editorial and Educational Adaptation: This material has been compiled based on the primary/original source text. The project team performed an editorial review, corrected technical inaccuracies, structured sections, and adapted the content for an educational format.

What was processed:

  • elimination of formatting defects (OCR errors, structural breaks, corrupted characters);
  • editorial organization of content;
  • standardization of terminology in accordance with academic sources;
  • verification of factual statements against the original source text.

All mentions of the author, publication year, and origin of the primary text have been preserved in accordance with the source.