The Endocrine System, Reproductive and Hormonal Functions of the Male, and Pineal Gland

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Spermatogenesis


Spermatogenesis is the process of formation of spermatocytes from spermatogonia







































      1. Sperminogenesis is the process of transformation of the spermatids, which are still epitheloid to sperm cells




Male Sex Hormones
  1. Testosterone is an anabolic steroid hormone secreted by Leydig cells of the testis
  2. Gonadotropin-releasing hormone increases release of the LH and FSH from the anterior pituitary gland
  3. LH stimulates testosterone formation by the Leydig Cells, and FSH stimulates spermatogenesis and sperminogenesis
  4. Inhibin is forced by Sertoli cells and inhibits FSH secretion

The Male Sexual Act

Male Infertility

Androgen dysfunction with normal sperm cell production
Isolated dysfunction of sperm cell production with normal androgen levels
Combined androgen and sperm cell production defects








MALE REPRODUCTIVE PHYSIOLOGY

  A. Testes Structure and Function
     1. Seminiferous tubules
     2. Sertoli cell functions
          a. Function of Inhibin
     3. Leydig cells secrete Testosterone (T)
          a. Functions of T 
  B. Regulation of Testes Function (HPG axis)
     1. Role of GnRH initiates puberty
          a.  Structure/function of the GnRh neuron
          b.  Importance of pulsatile GnRH secretion
     2. GnRH action at anterior pituitary: Release FSH and LH
     3. FSH and LH target the testes
         a. FSH increases spermatogenesis
         b. LH stimulates interstitial cells to release T, etc.
     4. Feedback: T and Inhibin inhibit hypothalamus and/or pituitary

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