hi class in this recording we're going to talk about the male active sex or the sexual response and as we look at males having sex um this can be divided up into four phases just like we do with females having sex with the excitement plateau orgasm phase and then finally resolution at the end and particularly for males dividing the male sexual response into four phases led to therapeutic treatment or the design of therapeutic treatments for sexual dysfunction in particular when it comes to the excitement and plateau phase related to erectile dysfunctions as we look at males the act of having sex and you're doing it is technically known as coitus or caution sometimes it's also referred to as copulation or if we want to also use another technical term we could say sexual reproduction or sexual intercourse so there's all these different words that mean the same thing now as we look let me just make sure i didn't go to okay yep we're good um i occasionally double click and go too many slides at once so as we look at the excitement phase during the excitement phase i want to emphasize parasympathetic so during the excitement phase we're going to have the erection forming so we have vasoconjection so the erectile tissue the corpora cavernosum and spongiosum are going to swell with blood so the male is going to go from flaccid to erect and as that male is going from flaccid to erect we find that there's going to be myotonia there'll be increased muscle tension throughout the body we're also going to have an increased heart rate in blood pressure and an increase in respiratory rhythm or pulmonary ventilation those bulbourethral calpers glands are going to secrete alkaline fluid to neutralize the acid within the male's urethra and we find that most of this erection that's that's stimulated from the parasympathetic nervous system is going to be triggered from nitric oxide secretion in particular we find that the pelvic nerve is going to send a signal to the penis and that it will pelvic nerve in particular will have those parasympathetic fibers and the one that stim when that pelvic nerve is stimulated we find that the penis becomes dilated we're going to have that nitric oxide causing dilation of the smooth muscles that lead that control the blood vessels to the penis so the penis becomes erect and we the penis needs to be erect so that it can gain entry into the vaginal canal during the plateau phase this is the um this is a period of time after erection but before orgasm or before ejaculation so this is typically going to be the thrusting phase to use kind of a crude term there and we find that the respiratory rate heart rate blood pressure all these variables are going to remain elevated and we're going to have the penis become increasingly erect so it goes from being erect and kind of soft to typically being erect and quite firm and there's going to be increased myotonia for some individuals this plateau phase can be a few seconds for other individuals it can be a few minutes before that orgasmic event occurs for the male reproductive system and then finally we have orgasm or climax and this orgasm or climax is typically gonna last three to fifteen seconds and this is going to have efferent nerve fibers traveling to the penis and that activation of the efferent nervous system is going to have a trigger a discharge of semen and during this time heart rate blood pressure and breathing rate respiratory rhythm are all going to dramatically increase um there's a little rhyme i can't take credit for this one but there's a rhyme to help you keep the branches of the nervous system straight when we look at the erection the erection is when the penis is stim or is caused by the parasympathetic nervous system ejaculation is caused by the sympathetic nervous system so when we think of erection i want you to think parasympathetic point when you think of the ejaculation i want you to think sympathetic shoot so if you can remember point and shoot you can remember that first the parasympathetic system causes the erection and then the sympathetic nervous system causes the ejaculation and then finally we have during this process of emission this ejaculatory phase the mission is going to be caused by sympathetic activation which is where we have that peristalsis uh through the fermented tubules through the vas deferens and the ejaculatory duct and then we have expulsion and during expulsion we are going to have semen within that urethra that is going to have further muscular contractions expel the semen out of the urethra so that there can be the semen um squirted into the female's reproductive tract typically for young males in their late teens and early 20s that have very great muscle tone that semen can be expelled with quite a bit of force it can even move upwards against gravity as we age we lose muscle tone and the force that the semen can be expelled into the females reproductive tract is going to diminish and that's one of the reasons why males have a harder time fathering children as they age this sympathetic reflex is also going to constrict the internal urethral sphincter of males and that's important because we don't want urine mixing with the semen that would dilute the semen and dilute the sperm of the semen and make it so that less sperm enters into the female's reproductive tract now as we think of ejaculation and orgasm they aren't necessarily the same i'll admit i tend to use them as synonyms but if we want to be very pedantic about it the ejaculation event is excuse me the ejaculation event is when we're going to have the mixing of the glandular secretions and then the orgasm event is that actual expulsion from the male reproductive tract after we have the resolution phase so this is the post ejaculation phase and this resolution phase is when we're going to go back to the baseline so we're going to have heart rate respiratory rhythm blood pressure all returned to normal the sympathetic symptoms signals are going to constrict that internal pudendal artery so instead of having the parasympathetic nervous system dilating the internal pudental artery the sympathetic nervous system constricts it and will reduce blood flow to penis causing the penis to become flaccid again as we look at the refractory period this is a period of time after having sex where the male is incapable of achieving another erection or orgasm generally speaking when we look at very young males that are in their teens early 20s and very healthy that can be as short as 10 minutes as the male ages that refractory period expands to as long as a few hours as we look at actually this is a good stopping point right here so we'll stop right here with resolution i forgot to put my stop marker in this presentation if you have any questions or comments about the act of having sex for males the male sex act please feel free to post those questions or comments in the class discussion board or to shoot me an email and as always class happy studies