Skip to main content
Back

Anatomy & Physiology: Reproductive System

Control buttons has been changed to "navigation" mode.
1/21
  • What is spermatogenesis?

    Spermatogenesis is the process of sperm cell development in the seminiferous tubules, involving mitosis of spermatogonia, meiosis to form spermatids, and spermiogenesis to produce mature sperm.

  • What are the three main stages of spermatogenesis?

    1. Mitosis of spermatogonia
    2. Meiosis producing spermatids
    3. Spermiogenesis transforming spermatids into sperm

  • What role do sustentocytes (nurse cells) play in spermatogenesis?

    Sustentocytes support developing sperm cells, form the blood-testis barrier, and regulate the environment for spermatogenesis by controlling substances and protecting haploid cells from immune attack.

  • How is male reproductive function hormonally regulated?

    By the hypothalamic-pituitary-gonadal (HPG) axis: GnRH from hypothalamus stimulates FSH and LH release from pituitary; LH stimulates testosterone secretion; FSH stimulates sustentocytes to release androgen-binding protein; testosterone and inhibin provide negative feedback.

  • What is the function of androgen-binding protein (ABP) in the testes?

    ABP binds testosterone in the seminiferous tubules, maintaining high local testosterone levels to stimulate spermatogenesis.

  • Describe the timeline of testosterone levels in males.

    High before birth, low during childhood, rises at puberty to adult levels, then remains fairly stable until late in life.

  • What are the major regions of a sperm cell and their functions?

    Head: contains nucleus and acrosome for egg penetration.
    Midpiece: contains mitochondria for ATP production.
    Tail: flagellum for locomotion.

  • What is oogenesis?

    Oogenesis is the production of female gametes (ova), beginning in the fetus with oogonia dividing to form primary oocytes that arrest in prophase I until puberty.

  • How does oogenesis differ from spermatogenesis?

    Oogenesis produces one functional ovum plus polar bodies, begins in fetal life and ends at menopause, and has a higher error rate; spermatogenesis produces four sperm continuously from puberty onward.

  • What are ovarian follicles?

    Ovarian follicles are saclike structures in the ovary cortex containing an immature oocyte surrounded by support cells, maturing through stages from primordial to vesicular follicles.

  • What happens during the follicular phase of the ovarian cycle?

    Several vesicular follicles grow under FSH stimulation; one becomes dominant, and its primary oocyte completes meiosis I to form a secondary oocyte and first polar body.

  • What occurs during ovulation?

    The mature follicle ruptures, releasing the secondary oocyte with its corona radiata into the peritoneal cavity.

  • What is the luteal phase of the ovarian cycle?

    After ovulation, the ruptured follicle forms the corpus luteum, which secretes progesterone and estrogen; if no pregnancy occurs, it degenerates into the corpus albicans.

  • What is the function of the uterus?

    The uterus receives, retains, and nourishes the fertilized egg; it has three layers: perimetrium, myometrium (muscle), and endometrium (mucosal lining).

  • What are the two layers of the endometrium and their roles?

    Functional layer (stratum functionalis) changes cyclically and is shed during menstruation; basal layer (stratum basalis) is permanent and regenerates the functional layer.

  • Describe the vagina's structure and functions.

    The vagina is a distensible tube with three layers: adventitia, muscularis, and mucosa; it serves as the birth canal, passage for menstrual flow, and copulatory organ.

  • How is the female reproductive cycle hormonally regulated?

    By interactions of GnRH, FSH, LH, estrogens, and progesterone, which regulate follicle development, ovulation, and uterine changes.

  • What are the effects of estrogens during puberty?

    Estrogens promote oogenesis, follicle growth, reproductive tract development, secondary sex characteristics, and a growth spurt.

  • What is the role of progesterone in the female reproductive system?

    Progesterone prepares and maintains the uterus for pregnancy and regulates the menstrual cycle during the luteal phase.

  • What is atresia in ovarian follicles?

    Atresia is the programmed cell death of ovarian follicles, the fate of most follicles that do not reach ovulation.

  • What is the significance of the blood-testis barrier?

    It protects developing sperm cells from immune system attack by isolating haploid cells in the adluminal compartment of seminiferous tubules.