Hormone hierarchical control

Figure 13.2 The hierarchical control of hormone release. Releasing hormones from the hypothalamus travel directly to the anterior pituitary hormones secreted by the anterior pituitary control most somatic endocrine glands. 

Hierarchical control and feedback control, both positive and negative, are a fundamental feature of endocrine systems (Figure 13.2). Each of the major hypothalamic-pituitary-hormone axes is governed by negative feedback ... 

The system is constructed hierarchically which allows an amplification of the signals registered in the hypothalamus. The hypothalamus-pituitary path can uptake nerve impulses and translate them into specific hormone production. A further characteristic of the system are regulatory mechanisms with whose help the formation and secretion of hormones can be controlled. The circulating hormone exerts a feedback inhibition at various levels thus ensuring that an overproduction of hormones is avoided. 

An Outline of Hormone Action (Figure 12.13, Figure 13.18, Figure 21.34, Figure 23,7) Hierarchical Nature of Hormonal Control (Figure 23.8, Figure 23,9)... 

Table 8 relates the specific principles of metabolic control to the hierarchical organization of metabolic control processes. The principles of metabolic control ascend through echelons of organizational complexity within hydrophobic and hydrophilic systems. As cumulative acquisitions of functions occur in the hydrophobic and hydrophilic systems, various metabolic functions emerge, with their attendent control mechanisms. In the hydrophobic system, there appear membrane systems, membrane transport, hormonal membrane receptors coupled to signal-molecule generating systems, membrane-bound enzymes, elec-... 

Figure 3. Hierarchical levels of metabolic control. Sites of metabolic control are designated as (1) plasma membrane level active transport systems, hormone receptors (2) cytoplasmic level hormone binding protein complex, signal molecule generation (3) enzymatic level steady-state enzymatic pathway, servomechanisms, enzyme degradation (4) ribosomal level protein biosynthesis (5) nuclear level hormonal control of gene action, operon control of gene action (substrate induction, product repression). The symbol,, indicates inhibition of a reaction.

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