Male Reproductive System: Components and Functions

• Reproduction sustains life by producing offspring.
• The structured approach provides a comprehensive overview of the reproductive systems and associated processes in both males and females, with essential components and functions highlighted for easy study and reference.

Male Reproductive System

• Functions of the male reproductive system include producing androgens like testosterone, producing spermatozoa (swimmers), and delivering sperm to the female reproductive system.
• Components of the male reproductive system include the testes, seminiferous tubules (in testes), epididymis, scrotum (skin sac covering testes), spermatic cord, vas deferens (ductus deferens), urethra, penis, prostate gland, bulbourethral glands, and seminal vesicles (vesicular gland).

Urethra

• The urethra is shared between the urinary and reproductive systems.
• It carries both urine and semen, but urine is temporarily blocked during ejaculation.
• The urethra has various sections: prostatic, pelvic (membranous), and penile portions.

Testes

• Testes typically hang outside the body for temperature regulation.
• Cooling Mechanism: The pampiniform plexus allows cooling without sending cool blood back to the body.
• Blood Supply: The testicular artery (L and R) comes directly off the aorta.
• Structure and Function of Testes includes semen production.
• Sertoli cells support spermatids.
• Leydig cells produce testosterone, which is influenced by ICSH.
• Spermatogenesis progresses from meiosis I to meiosis II.
• Spermatozoa Structure: The acrosome contains digestive enzymes to penetrate the ovum.
• Accessory reproductive glands include the prostate, seminal vesicles, and bulbourethral glands.

Female Reproductive System

• Functions of the female reproductive system: The vulva and vestibule are shared with the urinary system, but the urethra is not shared.
• Anatomy of the female reproductive system includes the ovaries, oviducts, uterus (with ligaments: broad, suspensory, round), cervix, vagina, and vulva.

Oogenesis

• Process: Oocytes develop in ovarian follicles; a fixed number of oocytes are present soon after birth; and meiosis produces a secondary oocyte and polar bodies.
• The ovarian cycle involves hormone regulation via FSH and LH and the development of the ovum.

Estrous Cycle Stages

• Proestrus is characterized by an enlarged vulva and bloody discharge.
• Estrus involves acceptance of the male and mating behavior.
• Diestrus is marked by non-acceptance of the male and hormone shifts.
• Anestrus is an inactive stage with no discharge.

Key Definitions

• Uniparous: Giving birth to one offspring.
• Multiparous: Giving birth to multiple offspring.
• Monoestrous: One cycle per breeding season.
• Diestrous: Two cycles per breeding season.
• Polyestrous: Multiple cycles (e.g., cow/swine).
• Seasonally polyestrous: Breeding cycles limited to certain seasons.

Fertilization and Development

• Capacitation of sperm leads to fertilization in the oviduct.
• The formation of a zygote is followed by cleavage to a morula and blastocyst.
• Implantation into the uterus occurs at the blastocyst stage.

Placenta and Gestation

• The placenta connects the embryo to the mother.
• Blood vessels are close but do not mix.
• Gestation is divided into trimesters, each with distinct developmental stages for the embryo and fetus.

Parturition

• Parturition is a process that starts with hormonal changes initiating uterine contractions.
• It involves several physiological processes to facilitate birth.

Mammary Glands and Lactation

• Mammary Glands and Lactation is not extensively covered for testing but may appear on the VTNE.