welcome to unit 10 reproductive and endocrine systems which is our final unit in anatomy and physiology 12. part 1 the male reproductive system please take the time to orient yourself with the male reproductive anatomy you can go to our handout section and find a blank one the answer key is also there please pause the video at this point introduction to the male reproductive system the scrotum is outside the abdominal cavity because the internal temperature of the body is too high for sperm the scrotum helps regulate the temperature of the testes by holding them closer or further away from the body unlike the female reproduction male reproduction is not governed by a cyclical pattern the path of sperm first we will look at the testes these are the male gonads they contain approximately 250 meters of tightly coiled synthesis tubules in these synephrous tubules mature sperm are produced by meiosis a process also called spermatogenesis the testes also have interstellar cells intracetal cells produce testosterone before puberty the tubules are solid cords they become hollow and start to function with purity next is the epididymis this is the place of sperm maturation including gaining mobility and storage of sperm they are tightly coiled tubules approximately five to six meters long just outside the testes next is the vas deferens this is a tube that takes the sperm from the epididymis to the urethra through the penis the first part stores the sperm and next is a uthra this carries both urine and semen in males during ejaculation the bladder is closed off so no urine comes out contributing glands these glands secrete products that contribute to semen production semen is seminal fluid plus sperm seminal vesicles this is found between the bladder and rectum and joints of vas deferens this releases fluid containing nutrients for the sperm in particular fructose next is the prostate gland this is found just below the bladder it adds an alkaline base approximately ph of 7.5 buffer to protect the sperm against the acidity of the vagina next is the calpers or bulbuthera gland this is found below the prostate gland it adds lubrication for sperm and better movement for your information movember is when some people grow a mustache to bring awareness to prostate cancer and help normalize talking about prostate cancer so sperm please take the time to sketch a diagram of sperm cell in the box below label the following structures chromosome tail middle piece mitochondria head nucleus and end piece please pause the video at this point great now i hope that you are able to have drawn a sperm cell so beside each label please write a brief description of the parts function you can pause the video again so now that you know approximately the anatomy and physiology of a sperm cell hopefully it looks something like this our nucleus is going to contain the dna the middle piece stores the mitochondria for energy the tail or end piece allows sperm to swim mitochondria found in the middle piece provides the energy the head houses the nucleus and the chromosome contains enzymes to penetrate the egg heuristics of testosterone a male hormone primary characteristics include development of that vast deference in other ducts maturation of external genitalia and sperm production secondary characteristics include deepening of voice distribution of hair and muscle growth regulations in male gnrah which stands for gonotrophic releasing hormone causes the anterior pituitary gland to release lh and fsh lh is luteinizing hormone this stimulates the interstellar cells in the testes to produce testosterone fsh the follicle stimulating hormone targets the semenephrus tubules which stimulates sperm production all are regulated by negative feedback hormone summary the gnrh is secreted by the hypothalamus which will target the anterior pituitary gland which will in effect increase fsh and lh which is secreted by the anterior pituitary gland will specifically target the interstitial cells within the testes which will increase testosterone fsh secreted by the anterior pituitary gland will target the seminiferous tubules within the testes to increase sperm production testosterone is going to be secreted by the testes which will affect the entire body this is going to create the onset of the primary and secondary sex characteristics part two the female reproductive system two functions of the female reproductive system first is to produce and deliver the female gamete the ovum which is also known as an egg and second provide an environment for a developing fetus please take the time to orientate yourself with the female reproductive anatomy please go to our handout section where you can find a blank copy of this and also the answer key please pause the video at this point first the ovaries the ovaries are female gonads containing follicles with immature eggs at various stages of maturation females are born with approximately 2 million follicles reduced to approximately 350 000 at puberty but only about 400 ever reached maturity in her lifetime the ovidocs ovidocs are also known as fallopian tombs you should be able to recognize both of these words oviducts extend from the ovary to the uterus for embryo transplant they have fingerlite projections called fimbria that sweep across the over yet and sweep the egg in as the ovary is not actually directly connected to the oviducts the tube is lined with cilia that create a current to carry the egg to the uterus egg is fertilized here if sperm is present the uterus this is also known as a womb it is a muscular pear-shaped organ normally the size of a fist but during pregnancy stretches to watermelon size there are three layers of the uterus the inner is a spongy endometrium which is full of blood this is expelled during menstruation the middle is a thick smooth muscle used to deliver baby expel the endometrium and assist the passage of sperm the outer is connective tissue this holds the organ in place next is the cervix this is the bottom of the uterus it's usually closed except to release the endometrium to deliver the baby and to let sperm in it acts as a bario barrier to microbes many white blood cells are nearby the vagina this is a small muscular tube the lining is folded and capable of being stretched during intercourse and birth the clitoris a small organ in front of the euthana related to the glands of penis highly sensitive enlarges during sexual arousal labia this is external forwards and it protects the internal genitalia estrogen functions which is the female hormone primary sex characteristics include vagina and uterus growth egg maturation onset of uterine cycle milk production when pregnant some secondary characteristics body hair widening of pelvis and hips breast enlargement and a fat layer beneath the skin part three the female reproductive cycles and hormones an interaction the female gonads are paired ovaries that lie in shallow depressions one on each side of the upper pelvic cavity the ovaries usually alternate in producing one oocyte per month oocyte is another word for egg hormone levels cycle on a monthly basis and the ovarian cycle drives the uterine cycle the ovarian cycle females are born with all the follicles they will ever have only about 400 of these will ever mature because a female usually only produces one oocyte per month during her reproductive years the ovarian cycle occurs as a follicle in the ovary matures and oogenesis is initiated and continues oogenesis is the production of an egg or an oocyte which is the female gamete during urogenesis eurogenesis ovulation occurs and the secondary oocyte is released from the follicle which then turns into a corpus luteum so when there is an egg present within the follicle it is called a focal once the egg is released from this follicle we call that follicle a corpus luteum ovulation this is a process of an oocyte bursting from an ovary and entering the oviduct which is also known as a fallopian tube the ovarian cycle first is the follicular phase which is days one through three gnrh the gonotrophin releasing hormone is released by the hypothalamus to act on the anterior pituitary gland the follicle stimulating fsh and luteinizing hlh hormones are produced by the anterior pituitary line this is very similar to the male reproductive system however now we will see a difference fsh promotes the follicle to develop an evolvery and produce estrogen lh promotes the corpus luteum to produce progesterone the follicle matures in the ovary the primary follicle changes into a secondary follicle which balloons out of the ovary wall as estrogen level in the blood rises it exerts a negative feedback control over the hypothalamus and anterior pituitary which stops the production of fsh high levels of estrogen trigger the hypothalamus to secrete a large amount of gnrh which causes the anterior pituitary to produce a surge of lh the next phase is ovulation this occurs on day 14. this is a surge of lh causing the egg to burst from the follicle for the ovary next is the luteal phase days 15-28 lh promotes the development of the corpus luteum which secretes progesterone and some estrogen as progesterone level in the blood rises it exerts a negative feedback control over the hypothalamus and anterior pituitary to stop the production of lh if there is no pregnancy the corpus luteum will degenerate after 10 days so that was the ovarian cycle next we'll move over to the uterine cycle these will be happening at the same time both female sex horizons the estrogen and progesterone have numerous functions one of which is to affect the endometrium causing the uterus to undergo a cyclical series of events known as a uterine cycle the uterine cycle occurs simultaneously with the ovarian cycle but it concerns the uterus not the ovaries and cycle menstruation days one to five at the end of the luteal phase low levels of hormones cause the endometrium to disintegrate and blood vessels to rupture blood and tissue pass out of the vagina during this menstruation proliferation staves stays 6-13 increased production of estrogen by a new ovarian follicle causes the endometrium to thicken ovulation day 14 same as during the ovarian cycle secretary phase days 15-28 increased production of progesterone by the corpus luteum causes endometrium to double or thicket triple in thickness the endometrial glands mature producing thick the endometrium is prepared to receive a fertilized egg which is also known as a developing embryo if no egg is fertilized or implanted the corpus luteum disintegrates and a low level hormones cause menstruation here you can see the uterine cycle at the bottom here's our follicular stage luteal phase okay days 0 14 28. menges is also known as menstruation so here you can see the different levels of our hormones esterol is similar to estrogen so you can follow this for estrogen you can see our lh which really spikes on day 14 and there is also a bit of a spike of the fsh the top here can see the ovarian cycle next fertilization and pregnancy pregnancy and birth fertilization requires that human gametes sperm and egg interact once an egg cell has been fertilized in the fallopian tube or oviduct the resulting cell is now diploid and referred to as a zygote the zygote continues to develop on its root to the uterus and after one week we'll implant into the wall of the uterus human development before birth is often categorized into two phases embryonic development months one to two and fetal development months three to nine fertilization is a successful union of sperm with an egg cell if fertilization occurs in the oviduct development begins immediately pregnancy about seven days later the embryo migrates an implant in the uterine wall a placenta forms which produces hcg the homocorniotic gonotrophin the estrogen and progesterone exert negative feedback on the anterior pituitary and hypothalamus so no new follicles are made ovulation does not occur again and the lining of the uterus is maintained birth baby's head puts pressure on the cervix the pressure receptors send nerve impulses to the hypothalamus oxytocin is made in the hypothalamus and stored in the posterior pituitary gland oxytocin is released from the posterior territory and causes the uterus to contract this is going to be positive feedback because the contractions bring about more contractions so during labor we see an increased estrogen oxytocin receptors are stimulated oxytocin is released the uterine contracts the fetal fetus is pushed on the cervix by pushing on the cervix more of these receptors are stimulated so oxytocin is released again so the more pressure there is the more oxytocin is formed which helps create even more pressure this is known as a positive feedback breastfeeding the baby pulls on the nipple and releases oxytocin same as birth which then brings down the milk this is also a positive feedback loop lactation is the secretion of milk by mammary glands menopause so now between the ages of 45 to 55 this age can vary a female will enter menopause this is when the ovarian and uterine cycles stop ovaries no longer respond to fsh and lh and stop producing estrogen and progesterone menstruation becomes irregular monopod is completed after one year of no menstrual cycle highly variable symptoms can include hot flashes from irregular circulation dizziness headaches depression either insomnia or sleepiness or no symptoms at all part six the endocrine system how do hormones travel they are released from an endocrine cell they travel through the blood and throughout the entire body hormones can bind to specific receptors or in the target cell the pituitary gland the anterior pituitary is a true endocrine gland the cells in the hypothalamus produce releasing hormones such as gnrh and trh these hormones are secreted into the capillaries and travel to the target cells in the anterior pituitary the anterior pituitary produces and releases a different hormone to the blood such as lh fsh and tsh the posterior pituitary is essentially an extended growth of the hypothalamus the hypothalamus produces some hormones that are stored in the capillaries in the posterior pituitary the posterior pituitary releases these hormones when needed some types of feedback maintaining homeostasis requires that the body continuously monitor its internal conditions it can do this by negative feedback negative feedback maintains body parameters within the normal range it stabilizes an upset in a body's physiological condition by preventing an excess response to a stimulus typically as the stimulus is removed so here on the left you can see a negative feedback loop the stimulus will affect the sensor control an effector and the effector will go back to the stimulus and stop this toxin is a hormone that regulates body metabolism and the growth of differentiation of tissues the hypothalamus will release trh which will then affect the anterior pituitary to create ths which will affect the thyroid gland to produce thyroxine as thyroxine is increased it's going to have a negative feedback loop on the anterior pituitary and hypothalamus stopping the production of thyroxine once enough thyroxine is produced it inhibits the thyme hypothalamus from producing any more trh this stops production of tsh this then stops the production of thyroxine if the level of thyroxine drops too low the hypothalamus will no longer be inhibited and will start to produce the trh again this is a classic example of a negative feedback loop positive feedback loops this intensifies a change in the body's physiological condition rather than reversing it like negative feedback group childbirth such as when a female is in labor is an example of this the stimulus which is the contractions push the baby towards the cervix the cervix contains stretch receptors which send messages to the pituitary gland to release oxytocin into the blood oxytocin causes stronger smooth muscle contractions in the uterus which push the baby towards the cervix thus making the cycle repeat and you did it this is the end of anatomy and physiology 12. wonderful job this course has a lot of information a whole new language you essentially learned so thank you for watching these videos and i hope that you enjoyed this time