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Male Reproductive Physiology and Spermatogenesis Notes

Chapter Overview

  • Focus: Reproductive System
  • Key Areas:
    • Male reproductive physiology
    • Spermatogenesis
    • Endocrinology
    • Female reproductive physiology
    • Oogenesis
    • Reproductive cycles

Male Reproductive Physiology

  • Sperm maturation takes about 74 days.
  • Main components:
    • Spermatogenesis: sperm production.
    • Endocrinology: study of hormones associated with the reproductive system.

Spermatogenesis

  • Definition: Sperm formation occurs in the seminiferous tubules.
  • Components involved in the process:
    • Spermatic cord
    • Blood vessels and nerves
    • Head and tail of epididymis
    • Ductus deferens
    • Interstitial cells

Structure of the Seminiferous Tubule:

  • Cross-section diagram components:
    • Sustenacular (Sertoli) cells: provide support and regulation for spermatogenesis.
    • Germ cells: include spermatogonia, spermatocytes, spermatids, and spermatozoa.
    • Relational positioning:
    • Spermatogonia: located along outer wall
    • Maturing spermatocytes: in the middle
    • Spermatozoa: closest to the lumen

Role of Sustentacular Cells

  • Also known as Sertoli cells.
  • Function:
    • Provide nutritional and metabolic support for developing sperm.
    • Regulate spermatogenesis with hormones and mediators.
    • Assist in the movement of cells toward the lumen of the tubule.

Maturation and Storage of Sperm

  • Location: Sperm mature and are stored in the epididymis and ductus deferens.
  • Structures involved:
    • Ureter
    • Urinary bladder
    • Seminal vesicle
    • Prostate gland
    • Bulbourethral gland

Endocrine Functionality

  • Interstitial endocrine cells (Leydig cells):
    • Found between seminiferous tubules.
    • Function: produce androgens, including testosterone.

Hormonal Regulation of the Reproductive System

  • Key hormones:
    • GnRH (gonadotropin-releasing hormone)
    • FSH (follicle stimulating hormone)
    • LH (luteinizing hormone)
  • Regulation Circuit:
    • GnRH stimulates the anterior pituitary
    • Anterior pituitary releases FSH and LH
    • FSH acts on Sertoli cells, while LH acts on Leydig cells for testosterone production.

Effects of Endocrine Dysfunction

  • Autoimmune disease impacting Leydig cells can lead to:
    • Reduction of testosterone production.
    • Possible impacts on estrogen levels depending on the balance of hormones.

Quiz Questions

  1. What would happen if interstitial endocrine cells were destroyed?

    • a) Testosterone production would plummet.
    • b) Estrogen levels would decrease.
    • c) Testosterone levels would soar.
    • d) Estrogen levels would increase.
  2. Which structure produces seminal fluid?

    • a) Testes
    • b) Seminal vesicles
    • c) Prostate
    • d) b and c
  3. Males produce gametes due to the presence of:

    • a) Type A daughter cells
    • b) Primary spermatocytes
    • c) Spermatozoa
    • d) Spermatogonia
  4. Hormones secreted by males include:

    • a) Testosterone
    • b) FSH
    • c) LH
    • d) All of the above.