Anterior pituitary gland hormones, blood

Q1 Thyroid secretion is controlled by two feedback loops. Secretion of T3 and T4 is stimulated by TSH from the anterior pituitary gland. The secretion of TSH is controlled by the hypothalamus via production of TRH. TRH is secreted by the hypothalamus into the hypophyseal portal blood flow. Stimuli such as a very cold environment influence the secretion of thyroid hormones by affecting the hypothalamus and increasing the release of TRH. 

Q4 Glucocorticoid secretion is controlled by the hypothalamus and anterior pituitary gland. Corticotrophin releasing factor (CRF) is produced in the hypothalamus and travels in the hypophyseal portal blood vessels to the anterior pituitary to release ACTH (adrenocorticotrophic hormone). There is a daily (circadian) rhythm in CRF and ACTH secretion, with a peak in the morning between 7 and 9 a.m. and a low point during the night. 

The master coordinator of hormonal activity in mammals is the hypothalamus, which acts on input that it receives from the central nervous system. Hormone secretion from the anterior pituitary gland is regulated by releasing hormones secreted by the hypothalamus. Neuroendocrine neurons in the hypothalamus project axons to the median eminence, at the base of the brain these neurons release substances into small blood vessels that travel directly to the anterior pituitary gland (the hypothalamo-hypophysial portal vessels). While the anterior pituitary... 

The anterior pituitary gland receives releasing factors from the hypothalamus in blood via a venous portal system. The releasing factors are hormones that regulate the secretions of the anterior pituitary gland. See Table 6.1 for actions and clinical uses of hypothalamic releasing factors. 

Growth hormone (GH) is an endocrine hormone produced and stored in the anterior pituitary gland, which is secreted into the blood circulation in a pulsation... 

ACTH is a hormone released by the anterior pituitary gland that influences the glucocorticoids that are secreted by the adrenal gland. Glucocorticoids affect carbohydrate, protein, and fat metabolism in addition to muscle and blood cell activity. 

The blood sugar level is maintained in accordance with the needs of the organism by the co-action of three hormones adrenaline, insulin and the glycotropic factor of the anterior pituitary gland. 

Figure 30-1 (A) Median sagittal section of the human brain. From Maya Pines.15 (B) Drawing illustrating the synthesis of peptide hormones in the hypothalamus and transport via portal blood vessels into the anterior lobe of the pituitary gland or via nerve tracts into the posterior lobe.16...

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