Page 5 - Module 1-Anatomy and Physiology of Growth Hormone Function Final (Interactive)
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Module 1: Anatomy and Physiology of Growth Hormone
Endocrinology and hormones
Endocrinology is the study of hormones, their synthesis, and where and how they act
on target organs. Hormones are really a type of messenger that produce specific
effects on cells and tissues. Hormone functions are depicted in Figure 1.
Figure 1. Hormone actions
Many different organ systems produce and secrete hormones that play important
roles in normal physiology. Hormones can be stimulated or inhibited by a group of
nonhormonal substances called growth factors. These are produced in different
tissue types and serve to regulate endocrine function.
Hormones can be divided into types based on their chemical structure, including
lipid-derived, amino acid-derived, and peptide hormones.
• The structure of peptide hormones is that of a polypeptide chain — a chain of
amino acids (Growth hormone is an example of a peptide hormone).
• Amino acid-derived hormones are relatively small molecules that are derived
from the amino acids, tyrosine and tryptophan.
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