The Reproductive System

Ureter

  • Description and anatomy of the ureter in relation to the reproductive system.

Vas Deferens

  • Pathway and function within male reproductive anatomy.

Seminal Vesicle

  • Overview of its role in semen production and secretion.

Prostate Gland

  • Function, location, and significance in the male reproductive system.

Bulbourethral Gland

  • Description of its contribution to semen composition.

Erectile Tissue

  • Composition and role in male sexual function.

Epididymis

  • Function in sperm maturation and storage prior to ejaculation.

Urethra

  • Pathway for urine and semen, detailing parts like prostatic, membranous, and spongy urethra.

Male Reproductive System Components

  - Testicle
  - Glans Penis

Female Reproductive System Components

  - Uterine Cavity
  - Fallopian Tube
  - Ovary
  - Cervical Canal
  - Ligament of Ovary
  - Endometrium
  - Vagina
  - Fimbriae

Chapter 27: The Reproductive System

General Information

  • Course: BIOL 207 Human Anatomy & Physiology II
  • Instructor: R. Adam Franssen, Ph.D.
  • Institution: Longwood University

Student Learning Outcomes

  • Anatomy Description: Detail the anatomy of male and female reproductive systems and their accessory structures.
  • Hormonal Functions: Explain the role of hypothalamic and pituitary hormones in male and female reproductive function.
  • Sperm Path: Trace the path of sperm from initial production to fertilization of an oocyte.
  • Ovary Events: Explain events occurring in the ovary prior to ovulation.
  • Development and Maturation: Describe the development and maturation of sex organs and the emergence of secondary sex characteristics during puberty.

Introduction to the Reproductive System:

Structures

  • Primary Sex Organs (Gonads):
      - Testes
      - Ovaries
  • Accessory Reproductive Organs:
      - Ducts
      - Glands
      - External genitalia

Functions

  • Primary Sex Organs:
      - Produce sex cells (gametes).
      - Secrete steroid sex hormones, including:
        - Androgens for males.
        - Estrogens and progesterone for females.
  • Role of Sex Hormones:
      - Development and function of reproductive organs.
      - Growth and development of other organs and tissues.
      - Influence on sexual behavior and drives.

Male Reproductive System:

Overview of Structures

  • Primary Reproductive Organ: Testes.
  • Accessory Reproductive Organs:
      - Ducts:
        - Epididymis
        - Ductus deferens (Vas deferens)
        - Ejaculatory duct
        - Seminal vesicles
        - Urethra
      - Glands:
        - Prostate
        - Bulbourethral glands (not shown)
      - External Genitalia:
        - Scrotum
        - Penis

Primary Function of the Male Reproductive System

  • Hormonal and Behavioral Control: Regulation of reproductive functions.
  • Production and Transport of Sperm: Including protective fluid (semen).
  • Discharge of Sperm: Within the female reproductive tract.

Testes Structure and Function

  • Functions:
      - Produce testosterone.
      - Produce and release sperm.
  • Duct Pathway for Sperm:
      - Seminiferous tubules
      - Tubulus rectus (straight tubule)
      - Rete testis
      - Efferent ductules
      - Epididymis

Sperm Production and Testes Anatomy

  • Lobules: Approximately 200 – 300 per testicle.
  • Seminiferous Tubules: Primary site of sperm production.
      - Spermatogenic Cells: Form sperm.
      - Sertoli Cells (Subtentacular Cells): Form blood-testis barrier; support and protect developing sperm cells.
      - Leydig Cells: Located in spaces between seminiferous tubules; produce testosterone.

Accessory Ducts Description

  • Ducts of Testes:
  • Epididymis: Site of sperm maturation and storage.
  • Ductus Deferens (Vas Deferens): Moves sperm during ejaculation.
  • Ejaculatory Ducts: Formed by the union of duct of seminal vesicle and ampulla of ductus deferens.
  • Urethra: Passageway for semen and urine (approximately 8 inches).
      - Parts:
        - Prostatic urethra
        - Membranous urethra
        - Spongy urethra
        - External urethral orifice

Accessory Glands and Semen Composition

  • Accessory Glands' Contributions:
      - Mostly liquid portion of semen secrets from:
        - Seminal Vesicles (60%): Located posterior to urinary bladder, secretes alkaline, fructose-containing fluid, and clotting proteins.
        - Prostate Gland (25%): Located inferior to bladder, surrounds prostatic urethra, milky slightly acidic fluid containing citric acid, proteolytic enzymes, and acid phosphatase.
  • Bulbourethral Gland (15%): Located inferior to prostate; secretes alkaline fluid to protect sperm and mucus for lubrication.

Male Sexual Response

Erections
  • Stimuli: Contact, thoughts, sights, sounds, smells lead to parasympathetic system activation.
  • Effects of Activation: Vasodilation and relaxation of smooth muscle allow blood to flow into erectile tissues, leading to rigidity of penis.
Ejaculation Reflex
  • Stages:
      - Emission Stage: Vas deferens contracts, propelling sperm from epididymis through ejaculatory ducts mixed with fluids.
      - Ejaculation: Bulbospongiosus muscle contraction leads to the expulsion of semen.

Mechanism and Effects of Testosterone

  • Functions