Hypothalamic control of the peripheral endocrine glands may utilize as many as three types of hormones, with multiple negative feedback controls, indicated by 0.

U Where is the pituitary gland located?

List the hormones that the anterior and posterior lobes of the pituitary gland secrete.

Explain how the hypothalamus controls the actions of the pituitary gland.

Anterior Pituitary Hormones

The anterior lobe of the pituitary gland is enclosed in a dense capsule of collagenous connective tissue and largely consists of epithelial tissue organized in blocks around many thin-walled blood vessels. Within the epithelial tissue are five types of secretory cells. They are somatotropes that secrete GH, mammatropes that secrete PRL, thyrotropes that secrete TSH, corticotropes that secrete ACTH, and gonadotropes that secrete FSH and LH (figs. 13.12 and 13.13). In males, LH (luteinizing hormone) is known as ICSH (interstitial cell-stimulating hormone) because it affects the interstitial cells of the testes (see chapter 22, p. 883).

Growth hormone, which is also called somato-tropin (STH), is a protein that stimulates cells to enlarge and more rapidly divide. It enhances the movement of amino acids through the cell membranes and increases the rate of protein synthesis. GH also decreases the rate at which cells utilize carbohydrates and increases the rate at which they use fats.

Secretory cells

Anterior Pituitary Gland Slide 100x

Light micrograph of the anterior pituitary gland (100x micrograph enlarged to 240x).

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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