Endocrinology

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Endocrinology
Salvador Dalí, 1952 Galatea of the spheres
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Learning Objectives

• To understand what the reproductive endocrine
  glands and hormones are.
• To understand the characteristics and functions
  of these hormones.
• To understand how the concentrations of these
  hormones in the blood are controlled.

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Endocrinology ?

• What is endocrinology?
• Study of structure function of endocrine glands
  and the role of their secretions (hormones)
• What is an endocrine gland?
• Organs or groups of cells which produce hormones
  and secrete them into the vasculature
• What is a hormone?
• A chemical messenger which travels via the
  circulation to reach target organs and
  subsequently elicit a specific effect

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Characteristics of hormones

• Present in circulation in low amounts
• Inhibit or accelerate reactions in cells
• Are not secreted at constant rates
• Require a specific receptor

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Characteristics of hormones

• Require a specific receptor

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Modes of Transmission

• Endocrine hormones transported by the blood to
  act on a distant organ. (classical definition)
• Neuroendocrine hybrid nerve secretes its
  chemical messenger, is taken into a capillary and
  carried to many cells.

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Modes of Transmission

• Paracrine hormones simply diffuse directly to
  neighboring target cells, by-passing the
  circulatory system.
• Autocrine a given cell may respond to its own
  hormone secretion.

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Locations of Some Endocrine Glands
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Classes of Hormones Proteins
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Classes of Hormones Steroids
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Classes of Hormones Prostaglandins
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Hypothalamus
Pituitary Gland
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Reproductive Hormones
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Reproductive Hormones
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