spermatogenesis & oogenesis

where does spermatogenesis occur?

the testes

seminiferous tubules

tube system where sperm are created

interstitial cells (Leydig cells)

cells that sit outside of the tubules and produce testosterone

germinal epithelium

layer of germline cells in the tubules that undergoes mitosis and meiosis. the sperm are produced in the center of the epithelium.

spermatozoa

the functional form of the gamete

sertoli cells (nurse cells)

they remove the cytoplasm from the developing sperm so their head is only a nucleus, which will later help with cell differentiation. they also help by providing nourishment for the developing sperm.

primary follicle/oocyte

the primary follicle is a single layer of cells surrounding the primary oocyte, which is a diploid and a precursor for mature eggs. the primary oocyte is arrested in prophase I before birth until it is selected for maturation during a female’s lifetime.

mature follicle

a sac of fluid containing the secondary oocyte

secondary oocyte

mature oocyte (haploid) arrested in prophase II and is released during ovulation.

polar body

a haploid nucleus produced from uneven cytokinesis during meiosis I. it lacks the critical organelles for survival and fertilization, so that the other one is prioritized with all the necessary nutrients.