The reproductive system allows organisms to reproduce. It consists of internal organs that produce gametes (eggs in females, sperm in males) and external genitalia. The male reproductive system includes testes that produce sperm and the female system includes ovaries that produce eggs. During pregnancy, the placenta connects the fetus to the uterine wall, allowing nutrient/gas exchange between mother and fetus.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. Reproductive System
3 Reproduction Terms
Prostate Gland
Testosterone
Placenta
9. Reproductive System
Prostate Gland
The 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.
10. 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.
11. Reproductive System
Testosterone
A 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 as
the 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.
12. Reproductive System
The fetus receives nourishment from its
mother by way of the Placenta.
13. 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 mother's blood supply.
The perfusion of the intravillus spaces of the placenta with maternal blood allows the
transfer 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.