 Hi everyone, this is Leah, your lead course instructor here at ACT, and welcome back to our anatomy and physiology lessons here. So today we are going to discuss the reproductive system, the male and the female reproductive system. So the male reproductive system includes a group of organs that make up a man's reproductive and urinary system, and these organs do the following jobs within the male body. They help to produce, maintain and transport sperm and semen and also these organs just discharge sperm into the female reproductive tract, and they also produce and secrete male sex hormones. The male reproductive system includes both internal and external structures, first we'll talk about the internal structures. We have that epidivitis, and this is a tightly coiled tube that is responsible for conducting the sperm from the tubule to the vas deferens. It's approximately 20 feet long, and some sperm are stored here along with semen. And then the sperm takes an estimated 12 to 20 days of travel along the epidermis and a total of 64 days to reach maturity. So next we have the vas deferens, and the function of the vas deferens is to carry the sperm through the anguinal canal from the epidermis into the abdominal cavity where it will end in the seminal vesicles and the ejaculatory gut. And so the vas deferens is a hollow tube that is protected by a thick fibrous coating and surrounded by arteries and veins. Next we have the seminal vesicles, and these are two convoluted pouches along the lower portion of the posterior surface of the bladder, and the seminal vesicles secrete a liquid that has high protein sugar and prostaglandolin content, which makes the sperm increasingly motile. So you can see in this diagram here all of these internal structures that we just discussed. So continuing on with the internal structures of the male reproductive system. We have the ejaculatory ducts, and these ducts pass through the prostate gland to join the seminal vesicles and the urethra. We have the prostate gland, and this is a chestnut sized gland that is situated below the bladder. It secretes a thin fluid that adds protection to the sperm from being immobilized by low pH levels of the urethra, and also the urethra passes through its center like a donut. So we also have the bolburethral gland, and these are also known as calper gland. These glands secrete alkaline fluid to counteract the acidic environment in the urethra. And these are two glands located at either side of the prostate gland and seminal vesicles and empty through short ducts towards the urethra. And semen is a product of 60% from the prostate gland, 30% from the seminal vesicles, and 5% from the epidemis, and 5% from the bolburethal urethra glands. And then last, of the internal structures of the male reproductive system, we have the urethra. And this structure passes through the prostate gland towards the shaft of the penis. It is a hollow tube from the base of the bladder and lined with a mucous membrane. It has a length of approximately 8 inches. The external structures of the male reproductive system include the scrotum, and you can see all of these structures that we're discussing right here in this diagram. So the scrotum is responsible for the support of the testes. It regulates the temperature of the sperm as well. It is very muscular, skin covered pouch over the perineum, and it promotes the production of the viable sperm. The scrotum contracts towards the body during very cold weather and relaxes away from the body during hot weather. So you have the testes, and each scrotum lies two oval-shaped glands called testes that we can see right here, and these are 2 to 3 centimeters in width and are encapsulated with a protective white fibrous capsule. So several lobules are contained in each testee and also contain cells that help produce testosterone and semi-infrared tubules that produce spermatoza. And in most men, one testee is slightly lower than the other to prevent trauma and easily sit or do any muscular activity. So next of the male reproductive system and the external structures of course includes the penis. The penis has 3 parts, first the corpus cavernosa and the other is the corpus bunginosum. So these erectile tissues also contain the urethra, making the penis an outlet for both urinary and reproductive functions. Erection of the penis is stimulated by the parasympathetic nerve innervations and the blood supply for the penis is from the penile artery. So the glands, a sensitive bulging range of tissue is located at the distal part of the penis and the prepris is a retractable casing of skin that protects the glands at birth and this is also the part of the penis that is surgically removed after birth during a circumcision. So how does the male reproductive system function? So it's dependent on hormones produced in the pituitary gland and the primary hormone involved in the functioning of the male reproductive system is the follicle stimulating hormone otherwise known as FSH and the luteinizing hormone LH and testosterone. So FSH is necessary for sperm production, LH stimulates the production of testosterone which is necessary to continue the process and testosterone is also important in the development of male characteristics including muscle mass and strength, fat distribution, bone mass and sex drive. So moving on to the female reproductive system, the female reproductive system consists of both internal and external structures just like the male reproductive system. It also has several important functions that include of course releasing eggs which can be potentially fertilized by sperm, producing female sex hormones such as progesterone and estrogen and providing an environment for a fertilized egg to develop during pregnancy and it also helps to facilitate labor in childbirth. So the female reproductive system has external structures. We'll start here. We have the labia manora and this is spread up to connective tissue folds that are pinkish in color. The internal surface is composed of a mucus membrane and the external surface is skin and it also contains sebaceous glands. The labia majora is lateral to the labia manora and are two folds of fat tissue covered by loose connective tissue, epithelium. Its function is to protect the external genitalia and the distal urethra and vagina from trauma. So it's covered in cubic hair that serves as an additional production against harmful bacteria that may enter the structure. And then we have the vestibule and this is a small flattened surface inside the labia where the openings to the urethra and the vagina arise. So some female reproductive, the external structures of the female reproductive system. Of course, we have the bartholin glands and these are located next to the vaginal opening on each side and produce a fluid or mucus secretion. And then we have the clitoris and that's covered by a fold of skin similar to the foreskin at the end of the penis. And just like the penis, the clitoris is sensitive to stimulation and can become erect. So if you need to know where these two external structures, just refer back to this diagram here on this page. So the internal structures of the female reproductive system include the vagina and the vagina is a canal that joins the cervix, which is the lower part of the uterus to the outside of the body. And this is also known as the birth canal. We have the uterus, otherwise known as the womb. And this is where a developing fetus is held. The uterus is divided into two parts, the cervix, which we just talked about, which is at the lower part of the vagina. And then the main body of the uterus is called the corpus. The corpus can easily expand to hold a developing baby and a canal through the cervix allows sperm to enter and menstrual blood to exit. So here's a diagram of the female reproductive system. If you need to, you can also refer to this diagram for the structures on the page that we just went over. So internal structures of the female reproductive system continued. We have the ovaries, of course, and these are small oval shaped glands that are located on both the right and the left side of the uterus. The ovaries produce eggs and hormones. And then we have the fallopian tubes. And again, we have two fallopian tubes, one on the right side, one on the left side. And these tubes are attached to the upper part of the uterus and serve as a pathway for the eggs or the ova to travel from the ovaries to the uterus. Fertilization of an egg by a sperm normally occurs in the fallopian tubes, and the fertilized egg then moves to the uterus where it implants to the uterine lining. So the menstrual cycle, so females of reproductive age experience cycles of hormonal activity. And this goes on during one month intervals with each cycle a woman's body actually prepares for potential pregnancy, whether that is her intention or not. So the term menstruation refers to the periodic shedding of the uterine lining. And the average menstrual cycle takes about 28 days, and it occurs in three phases, the follicular phase, the ovulatory phase, and then the luteal phase. So here we have the follicular phase. This phase starts on the first day of the period. And during the follicular phase, the menstrual cycle, the two hormones, Fs, Fsh, and Lh are released from the brain and travel in the blood to the ovaries. And the hormones stimulate the growth of about 15 to 20 eggs in each ovary. These hormones then trigger an increase in the production of the female hormone estrogen. And as estrogen levels rise, it turns off the production of the Fs, Fs, Fs, oh my gosh, Fsh. So this careful balance of hormones allows the body to limit the number of follicles or eggs that mature. And as the follicular phase progresses, one follicle in one ovary becomes dominant and continues to mature, and this dominant follicle suppresses all others. As a result, they stop growing and die, and then the dominant follicle continues to produce estrogen. The ovulatory phase or ovulation starts 14 days after the follicular phase has started. And this is about midpoint in the menstrual cycle with the next menstrual period starting about two weeks later. So this is during the phase when the woman is most likely to become pregnant during sexual activity. So as the egg is released, it is captured by projections on the end of the fallopian tubes. And then those projections kind of sweep the egg into the tube. And during this phase, the amount and thickness of mucus produced by the cervix. And again, as I said, during this phase, the woman is most likely to become pregnant. So this thick mucus captures the man's sperm and nourishes it and helps it to move towards the egg for fertilization. Then we have the last phase of the menstrual cycle, which is the lethal phase. And this begins right after ovulation and involves once the egg is released, the empty follicle develops into a new structure called the corpus luteum. The corpus luteum secretes the hormone progesterone. And progesterone really prepares the uterus for a fertilized egg to implant. So if the woman were to become pregnant during this time, the fertilized egg or the embryo would then travel through the fallopian tube to implant into the uterus. And now the woman is now considered to be pregnant. So if the egg is not fertilized, it passes through the uterus, not needed to support pregnancy, the lining of the uterus then breaks down in sheds and otherwise known as period or when you're bleeding, and then the next menstrual cycle begins. So the four major hormones involved in the menstrual cycle include, like I said, the FSH, which we just went over and it's produced by the pituitary glands. We have the LH, Lutinizing Hormone, also produced in the pituitary gland. We also have estrogen, ovaries produce most of the estrogen during reproductive years. Also the adrenal glands and adipose tissues secrete estrogen as well. And then you have progesterone and this hormone is produced in the ovaries and the placenta and the adrenal glands and that again helps to, helps to prepare the body for conception and pregnancy and really regulates the menstrual cycle. So this concludes the reproductive system. Again, if you have any questions or you need me to clarify anything for you, please always outreach me via email or you can always schedule office hours with me. Thanks and we'll see you again soon.