Question

Once a month my colleagues from the Society for Neuroscience living in the Chicagoland area get together at a bar for a talk about an area of research. You are studying the role of hormones in development of sexual identity and the stages of reproductive behaviors in rats and have been asked to give a talk, but instead of rats you have been asked to relate the four stages reproductive behavior to humans. The audience are fellow research, you want to be professional, accurate, and slightly entertaining.

Answer 1

Approximately after 10 years of age, females reach puberty. The hypothalamus starts secreting the gonadotropin releasing hormone (GnRH). The GnRH stimulates the anterior pituitary gland to release FSH (follicle stimulating hormone) and LH (luteinizing hormone). These two hormones act on gonads and cause the maturation of ovum in females and release of testosterone in males.

Females experience a monthly menstrual cycle, during which the ovum is released during the mid-cycle (15th day of ovarian cycle). The LH surge causes ovulation to occur and the reproductive tract becomes more receptive during this period to favour reproduction. During puberty, the maturation of reproductive organs causes semen secretion in males that contains spermatozoa (male gametes). After sexual intercourse, the spermatozoon and ovum (fertilization) unites in the fallopian tube. The spermatozoon permeates into the ovum and results in fertilization. Fertilization is followed by various developmental stages of zygote.