The Reproductive system The reproductive system and it common pathologies

Functions of the reproductive system Reproduction occurs in all living organisms, to produce a new member of a species The human reproductive system is unique, in that it is the only system in the body that produces cells that have 23 chromosomes instead of 46. These are called reproductive or haploid cells.

Remember mitosis? Interphase Metaphase Anaphase Telophase Task; How does Meiosis differ and when?

Mitosis vrs meiosis Characteristic Mitosis Meiosis Description Somatic cell division Reproductive cell division Function For growth and repair of cells For reproducing a new organism Number of daughter cells 2 4 Are daughter cells identical? Identical – exact copies Different – allows for genetic variation Number of chromosomes in each daughter cell 46 = two sets, diploid number 23 = one set, haploid number

Female Sex hormones Oestrogen: affects secondary sexual characteristics in females; development of female reproductive system, external genitalia, uterus and breasts, regulates menstrual cycle Progesterone: affects structures involved in pregnancy; maintenance of pregnancy, development of the placenta, preparation of breast for lactation

The female reproductive tract

The female reproductive tract

The breasts

The menstrual Cycle Cycle Begins (Follicular Phase) Endometrial lining (lining the uterus) sheds. Hypothalamus, a region of the brain, produces gonadotropin-releasing hormone (GnRH), which is necessary for the release of follicle-stimulating hormone (FSH) from the pituitary gland. FSH causes small follicles to develop inside the ovary. One follicle begins to grow larger and secretes estrogen, a female hormone. This dominant follicle produces a cell (an oocyte) that will become an ovum, or egg.

The menstrual cycle Within days after menstrual bleeding begins, the endometrial lining begins to rebuild, stimulated by increased production of estrogen. In the early part of the menstrual cycle, a woman may notice thick and sticky cervical mucus. As estrogen increases, mucus becomes thin, watery and clear. After ovulation, the mucus again becomes cloudy and thick.

Menstrual cycle

The menstrual cycle Cycle Begins (Follicular Phase) Around midcycle, increasing estrogen levels stimulate secretion of GnRH and another hormone from the pituitary gland, the luteinizing hormone (LH). This LH hormone, in turn, triggers the release of the egg from the ovary (ovulation), and stimulates the production of a second female hormone, progesterone. Ovulation occurs within 12 hours after LH production reaches its peak. As LH peaks, estrogen levels temporarily drop, and this can cause midcycle bleeding for some women. As the ovarian follicle ruptures, some women experience abdominal pain.

The menstrual cycle An unfertilized egg lives only up to 24 hours after ovulation. However, sperm cells can live as long as five days in the female reproductive tract. If sperm are present as the egg travels from the ovary through the fallopian tube, fertilization can occur.

The menstrual cycle An unfertilized egg lives only up to 24 hours after ovulation. However, sperm cells can live as long as five days in the female reproductive tract. If sperm are present as the egg travels from the ovary through the fallopian tube, fertilization can occur.

The menstrual cycle f the egg is fertilized, production of estrogen and progesterone continues and the endometrial lining becomes even thicker. The fertilized egg may become implanted in the endometrial lining. The endometrial lining does not shed, and the pregnant woman's menstrual period does not begin. If fertilization does not occur, estrogen and progesterone levels fall, the endometrial lining sheds, and menstrual bleeding begins again.The cycle, about 28 days, varies from women to woman, and can vary during the same women's life.

The menstrual cycle Near Midcycle (Luteal Phase) The ruptured follicle, now called the corpus luteum, begins to produce estrogen and progesterone. Increased amounts of estrogen and progesterone cause a decrease in FSH and LH and cause a change in the endometrial lining. The lining becomes thicker and its blood supply increases, preparing the lining to accept an embryo if fertilization and implantation occur.

Male reproductive tract

Male sex hormones Androgens: development of male reproductive system, male hair growth patterns, voice deepening, muscle bulk Testosterone: controls male secondary sex characteristics and promotes development of sperm in the testes

Task There are several stages to puberty for both male and females. Investigate briefly how each of the following; Puberty (male & female) Pregnancy Menopause (male & female)

Fertilisation of an egg

Pathologies of the reproductive system common pathologies of the reproductive system; polycystic ovarian syndrome (PCOS) impotence menstrual problems i amenorrhoea dysmenorrhoea premenstrual syndrome post-natal depression infertility mastitis