Male Sexual Response Flashcards
what is the penis
male external sexual organ
function of the penis
- transport urine from bladder to exterior
- transport semen from male reproductive system into female vagina duirng intercourse
structure of the penis in descending order
- root (base of penis; fixed portion attached to body wall)
- body / shaft (moveable, tubular part; part that flaccid or erect)
- neck (between shaft and glans)
- glans or head (expanded end around urethral opening)
- prepuce (foreskin; covers glans of penis in uncircumcised)
penis supporting tissue layers (superficial to deep)
- outer skin (similar to scrotum - thin, delicate)
- dermis (has smooth muscle continuous w dartos smooth muscle found in scrotum)
- underlying areolar loose CT (to allow skin to move)
- elastic tissue (encircling internal structures; allows penis to stretch and recoil back to normal shape)
are the penis supporting tissues involved in erection
no
penis erectile tissue
(two blue large circles, red circle - general area)
- erectile tissue are deeper than supporting tissues
- well-vascularised (tissues can fill with blood - allowing erection) (when blood drains from tissues - penis resting / flaccid)
- in resting state, arterial branches are constricted
- corpora cavernosa - 2 bands of erectile tissue; on either side of penis
- corpora spongiosum - around penile urethra; on underside of penis
describe structure corpora cavernosa tissue
- 2 bands of erectile tissue; on either side of penis
- tissue contains empty spaces (/ lacunae) -> empty when penis flaccid; filled with blood when penis erect
- dorsal side of penis (side facing abdomen when erect)
- around deep artery of penis
describe structure corpora spongiosum tissue
- around penile urethra; on underside of penis
- tissue contains empty spaces (/ lacunae) -> empty when penis flaccid; filled with blood when penis erect
what is it structurally that causes an erection
the filling of the spaces within corpora cavernosa and corpora spongiosum (the penis erectile tissues) with blood
where does the blood that fills the penis erectile tissue come from
- penile arteries
how many phases is male sexual response made up of
3
- arousal / excitement
- orgasm and ejaculation
- resolution
(male sexual response: 1. arousal / excitement)
what can arousal be triggered by
- thoughts, images, touch, scents, other stimuli, etc
(male sexual response: 1. arousal / excitement)
what does triggered arousal lead to
- increased HR, breathing, BP
- in penis, increased parasympathetic stimulation thru pelvic nerves
(male sexual response: 1. arousal / excitement) what does parasympathetic stimulation thru pelvic nerves do
- parasympathetic nerves enter the penis
- parasympathetic stimulation causes release of nitric oxide within penis
- nitric oxide causes penile smooth muscles around penile arteries to relax
(male sexual response: 1. arousal / excitement) mechanism of action for erection
- penile arteries dilate (muscles around arteries relax) -> blood flows into arteries -> blood leaks out of arteries -> blood makes way into lacunae / spaces within erectile tissue -> spaces fill with blood (ie/ engorged or swollen with blood) -> penis becomes erect
(male sexual response: 2. orgasm and ejaculation) are orgasm and ejaculation the same thing
- no
- two different bodily functions
(male sexual response: 2. orgasm and ejaculation) describe orgasm
- cerebral (brain) response to what is happening
- sense of pleasure
- orgasm can occur even if male does not ejaculate
(male sexual response: 2. orgasm and ejaculation) describe ejaculation and involved muscles
- release of semen
- many muscles along sides of penis ‘ischiocavernosus muscles’ stiffen erect penis
- ‘bulbocavernosus muscles’ at base of penis contract to push semen toward external urethral opening
(male sexual response: 3. resolution) describe resolution
returning to the normal state
(male sexual response: 3. resolution) MoA of end ejaculation during resolution
- sympathetic signals constrict deep arteries of penis (by causing muscles around arteries to constrict) -> reduce blood flow into penis
- plus blood flows out of penis normally
=> penis becomes soft and flaccid
(male sexual response: 3. resolution) what happens during resolution
- erected state subsides (2 events)
- cardiovascular and respiratory responses return to normal (HR, breathing, BP)
when does refractory period occur and for how long
- occurs immediately after resolution phase
- last from 10 minutes up to a few hours (vary for individual)
describe refractory period
- period where body recalibrates itself and settles down after gone through male sexual response
- period where body returns to normal state
- period where another sexual response does not occur (10 mins up to few hrs - varies)
what might be difficult for males during refractory period
- to get another erection
- to achieve subsequent orgasm
during refractory period what might sexual stimulation be like & are there any exceptions
- too sensitive and even painful during this period
- but possible for some individuals
after refractory period has passed what can then occur
another sexual response
define impotence
inability to achieve or maintain erection
does impotence affect many males & what demographic is affected by impotence
- yes, quite a few
- affects as males get older
- 40+ yrs old - tends become more prominent issue
what is impotence also known as
erectile dysfunction (ED)
some causes of ED / impotence
- vascular changes
- neural commands changing
- psychological factors
- many causes of ED
are there many ways to treat ED and why or why not
yes many ways to treat ED
since many different causes of ED
what would be a possible treatment option for a psychological cause of ED
psychological treatment
what is a common medication treatment option for ED
viagra
what is cGMP
explain biochem behind erection
- cGMP is the biochemical behind the nerve signals that go to penis causing dilation of arteries / relaxation of surrounding smooth muscle
- cGMP causes vessels in penis to expand
- allowing blood to enter
- causing erection
what happens in ED biochemically
- PDE5 chemical present in body in ED males
- PDE5 breaks down cGMP quickly which stops it from binding to smooth muscle to dilate blood vessels for erection to occur
how does viagra work on PDE5 on ED males
- viagra = chemical that when taken blocks PDE5 from breaking down cGMP
=> cGMP able to act normally
