Male Reproductive System Overview

General Embryology

• This is a study of the development of an embryo

Reproductive System

• The Reproductive System is a complex system.

Male Reproductive System

• Internal Genital Organs:
  • Epididymis
  • Vas Deferens
  • Seminal Vesicles
  • Ejaculatory Duct
  • Urethra
• External Genital Organs:
  • Penis
  • Scrotum
  • Testes

Testis

• Small, oval organ, in the scrotum
• Coverings:
  • Tunica Vaginalis (serous membrane)
    • Parietal layer
    • Visceral layer
  • Tunica Albuginea (tough fibrous capsule)
    • Forms internal septa with 250 lobules per testis
    • Each lobule has up to 4 seminiferous tubules
• Functions:
  • Form sperms
  • Secrete androgens

Series of tubes in the Testes

• 1. Seminiferous tubules
• 2. Straight ducts
• 3. Rete testis
• 4. Efferent ductules
• 5. Epididymis
• 6. Ductus Deferens

Descent of the Testes

• Movement of testes through inguinal canal into scrotum
• Occurs during fetal development

Epididymis

• Location: Behind the testis
• Formed of: Head, body, and tail
• Coiled tube: 6m long
• Function: Store & nourish sperm and allow them to mature. The tube emerges from the tail of the epididymis into the vas deferens.

Vas Deferens (Ductus Deferens)

• Thick-walled tube, 45cm long
• Function: Conveys mature sperm from the epididymis to the ejaculatory duct and urethra.

Urethra

• Transports semen from the ejaculatory duct to the outside of the body
• Subdivided into:
  • Prostatic urethra
  • Membranous urethra
  • Penile urethra

Female Genital System

• Internal genital organs
  • Ovaries
  • Fallopian tubes (oviducts)
  • Uterus
  • Vagina

Ovary

• Female primary sex organ
• Paired, almond-shaped
• Size: 3 x 2 x 1 cm
• Site: Usually lies in ovarian fossa (depression) on side wall of pelvis
• Formed of: Cortex (developing oogonia) & Medulla (connective tissue & blood vessels)

Functions of Ovaries

• Produce ova
• Synthesize and secrete female sex hormones

Uterine Tubes (Fallopian Tubes)

• Muscular tube (10 cm)
• Has two ends:
  • Medially into cornu
  • Laterally into peritoneal cavity
• Formed of four parts:
  • Infundibulum
  • Ampulla
  • Isthmus
  • Intramural

Functions of Uterine Tubes

• Receives ovum from the ovary
• Site for fertilization
• Provides nourishment
• Transport ova to the uterus
• Conduit for spermatozoa to reach the ovum
• Synthesizes and secretes female sex hormones

Uterus

• Thick-walled muscular organ (8 x 5 x 3 cm)
• Hollow, pear-shaped
• Formed of:
  • Fundus (upper part)
  • Body (middle part)
  • Cervix (lower part which projects into the vagina)

Cervix

• Pierces the anterior wall of the vagina
• Divided into:
  • Supravaginal part
  • Vaginal part

Normal Positions of the Uterus

• Anteversion: Long axis of the uterus is bent forward on the long axis of the vagina
• Anteflexion: Long axis of the body of the uterus is bent forward at the level of the internal os with the long axis of the cervix

Uterus (Frontal Section & Tissues)

• Sections
  • Endometrium
  • Myometrium
  • Perimetrium

Function of Uterus

• Serve as a site for reception, retention, and nutrition of the fertilized ovum

Vagina

• Muscular canal (10 cm)
• Upper part lies in the pelvis
• Lower part lies in the perineum
• Anterior wall is pierced by the cervix
• Functions (in summary): female genital canal, excretory duct for the menstrual flow, part of the birth canal

Gametogenesis (Meiosis)

• The process of producing gametes (ova and sperm) through a kind of cell division called meiosis.

Spermatogenesis

• Process of sperm formation within the seminiferous tubules of the testes
• Regulated by LH & FSH
• PGCs stay dormant from 4th week till puberty
• Then enter meiosis and produce sperm from puberty until death

Oogenesis

• The process of ovum production, occurring monthly in ovarian follicles.
• Parts of ovarian cycle:
  • Follicular phase (preovulatory)
  • Luteal phase (postovulatory)

This quiz covers the internal and external structures of the male reproductive system, focusing on the testis and its functions. You will explore various components such as the epididymis, vas deferens, and the process of testis descent. Understand the organization of seminiferous tubules and their role in sperm production.