Male Reproductive Anatomy (Front View) Seminal vesicle (behind bladder) (Urinary bladder) Prostate gland Bulbourethral gland Urethra Erectile tissue of penis Scrotum Vas deferens Epididymis Testis

Male Reproductive Anatomy (Side View) (Urinary bladder) (Urinary duct) Seminal vesicle (Rectum) (Pubic bone) Vas deferens Erectile tissue Ejaculatory duct Prostate gland Urethra Penis Bulbourethral gland Glans Vas deferens Epididymis Testis Scrotum Prepuce

Female Reproductive Anatomy (Front View) Oviduct Ovaries Follicles Corpus luteum Uterine wall Uterus Endometrium Cervix Vagina

Female Reproductive Anatomy (Side View) Oviduct Ovary Uterus (Urinary bladder) (Rectum) (Pubic bone) Cervix Urethra Vagina Shaft Glans Clitoris Prepuce Labia minora Labia majora Vaginal opening

Spermatogenesis Epididymis Seminiferous tubule Testis Cross section of seminiferous tubule Primordial germ cell in embryo Mitotic divisions Sertoli cell nucleus Spermatogonial stem cell 2n Mitotic divisions Spermatogonium 2n Mitotic divisions Primary spermatocyte 2n Meiosis I Lumen of seminiferous tubule Secondary spermatocyte n n Meiosis II Neck Spermatids (at two stages of differentiation) Early spermatid n n n n Tail Midpiece Head Plasma membrane Differentiation (Sertoli cells provide nutrients) Mitochondria Sperm n n n n Nucleus Acrosome

Spermatogenesis (Expanded View) Epididymis Seminiferous tubule Sertoli cell nucleus Spermatogonium Testis Primary spermatocyte Cross section of seminiferous tubule Secondary spermatocyte Spermatids (two stages) Lumen of seminiferous tubule Sperm

Spermatogenesis Primordial germ cell in embryo Mitotic divisions Spermatogonial stem cell 2n Mitotic divisions Spermatogonium 2n Mitotic divisions Primary spermatocyte 2n Meiosis I Secondary spermatocyte n n Meiosis II Early spermatid n n n n Differentiation (Sertoli cells provide nutrients) Sperm n n n n

Anatomy of Spermatozoon Neck Tail Midpiece Head Plasma membrane Mitochondria Nucleus Acrosome

Oogenesis 2n 2n n n n n Ovary Primary oocyte within follicle In embryo Growing follicle Primordial germ cell Mitotic divisions 2n Oogonium Mitotic divisions Primary oocyte (present at birth), arrested in prophase of meiosis I 2n Mature follicle Ruptured follicle Completion of meiosis I and onset of meiosis II First polar body n n Secondary oocyte, arrested at metaphase of meiosis II Ovulated secondary oocyte Ovulation, sperm entry Completion of meiosis II Second polar body Corpus luteum n n Fertilized egg Degenerating corpus luteum

Oogenesis (Expanded View) Ovary Ruptured follicle Primary oocyte within follicle Ovulated secondary oocyte Growing follicle Corpus luteum Mature follicle Degenerating corpus luteum

Oogenesis (Expanded) 2n 2n n n n n In embryo Primordial germ cell Mitotic divisions 2n Oogonium Mitotic divisions Primary oocyte (present at birth), arrested in prophase of meiosis I 2n Completion of meiosis I and onset of meiosis II First polar body n n Secondary oocyte, arrested at metaphase of meiosis II Ovulation, sperm entry Completion of meiosis II Second polar body n Fertilized egg n

Anatomy of Ovum Second polar body

Spermatogenesis v. Oogenesis