Reproductive System What is the Reproductive System? It is a system of organs within an organism which work together for the purpose of reproduction Unlike most organ systems, the sexes of differentiated species often have signiﬁcant differences. These differences allow for a combination of genetic material between two individuals, which allows for the possibility of greater genetic ﬁtness of the offspring. Reproductive systems can be divided into the internal reproductive organs and the external genitalia. The gonads are the actual organs that produce the gametes. In the male, testes produce sperm, and in the female, ovaries make eggs.
Reproductive System Male Reproduction The male reproductive system is illustrated below. Sperm are produced in the testes located in the scrotum. Normal body temperature is too hot thus is lethal to sperm so the testes are outside of the abdominal cavity where the temperature is about 2° C (3.6° F) lower.
Reproductive System Male Reproduction If a man takes too many long, very hot baths, this can reduce his sperm count. Sperm are transferred to the epididymis, coiled tubules also found within the scrotum, that store sperm and are the site of their ﬁnal maturation.In ejaculation, sperm are forced up into the vas deferens (plural = vasa deferentia). From the epididymis, the vas deferens goes up, around the front of, over the top of, and behind the bladder.
Reproductive System Female Reproduction The female reproductive system is illustrated below. “Eggs” are produced in the ovaries. A woman’s body temperature is lowest around the time of ovulation to help insure sperm live longer to reach the egg.
Reproductive System Female Reproduction Only several hundred “eggs” (of about 400,000 produced) will actually ever be released during her reproductive years. Ovulation is the release of a mature “egg” due to the stimulation of leutenizing hormone (LH), which then stimulates the remaining follicle cells to turn into a corpus luteum which then secretes progesterone to prepare the uterus for possible implantation. If an egg is not fertilized and does not implant, the corpus luteum disintegrates and when it stops producing progesterone, the lining of the uterus breaks down and is shed.
Reproductive System 3 Reproduction Terms Prostate Gland Testosterone Placenta
Reproductive SystemThe single prostate gland is located just below the urinary bladder.
Reproductive System Prostate GlandThe prostate gland is about the size of a walnut and surrounds the neck of a man’s bladder and urethra.As part of the male reproductive system, the prostate gland’s primary function is to secrete a slightly alkaline ﬂuid that forms part of the seminal ﬂuid, a ﬂuid that carries sperm. During male climax (orgasm), the muscular glands of the prostate help to propel the prostate ﬂuid, in addition to sperm that was produced in the testicles, into the urethra.
Reproductive System The male sex hormone Testosterone, which is responsible for the development of the male reproductive organs, sperm, and secondary sex characteristics, is all produced by the testes.
Reproductive System TestosteroneA steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In men, testosterone plays a key role in the development of male reproductive tissues such asthe testis and prostate as well as promoting secondary sexual characteristics such as increased muscle, bone mass, and the growth of body hair.On average, in adult human males, the plasma concentration of testosterone is about 7-8 times as great as the concentration in adult human females plasma.
Reproductive System The fetus receives nourishment from its mother by way of the Placenta.
Reproductive System Placenta An organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mothers blood supply. The perfusion of the intravillus spaces of the placenta with maternal blood allows thetransfer of nutrients and oxygen from the mother to the fetus and the transfer of waste products and carbon dioxide back from the fetus to the maternal blood supply. Adverse pregnancy situations, such as those involving maternal diabetes or obesity, can increase or decrease levels of nutrient transporters in the placenta resulting in overgrowth or restricted growth of the fetus.