Orgasm in the Male

Orgasm in the Male
Presentation by: Dr.Li Ming Shun

Frequency of Sex with a Partner:
18-24 yr old Males
Frequency of Masturbation:
Total Population
Masturbation: Males 18-24
* Interesting data: 85 % of men living with a sexual partner masturbated in the previous year. 80% of men with advanced degrees masturbated in the previous year.
“Phallic Fallacies”
* The larger the penis, the more effective the male partner in coital connection with the female. May be valid for anal sex with male partner (b/c of location of prostate)
* Little relation of size erect to size flaccid
* No relation of skeletal stature to penis size

Male Sexual Response Cycle
Variant Arousal in Males
* Too much arousal:
o Priapism
o Premature ejaculation
* Too little arousal:
o Impotence (“ED”)

Priapus: God of Fertility and Gardening
Priapism
* Non-sexual origin
* Usually due to blood vessel pathology or nerve disorders.

Premature Ejaculation

* Male inability to control ejaculation for a sufficient length of time during intravaginal containment to satisfy his partner at least 50% of the time.
* Not a “stopwatch” definition
* Usually psychological in origin
* Treated by “training”
Impotence

* Inability to achieve an erection even with effective sexual stimulation
* Psychological basis
* Physiological basis
Primary Impotence

* Never able to have or maintain a functional erection
* Most often psycho-social basis
* Rarely physiological basis
Secondary Impotence

* History of adequate erections
* Psycho-social basis
o Fear of failure
o Lack of interest
* Physiological basis
o Cardiovascular pathology (e.g., diabetes; arteriosclerosis)
o Nerve damage (injury, stroke)
o Medications

Test for erections during REM sleep
Agents that affect erections
* Viagra: vasodilation (promotes erections)
* Poppers: vasodilation; also relaxation of vagina and anal sphincter
* Alcohol: blocks vasodilation (no NO)
* Nicotine: vasoconstriction
* Ecstasy: decreased libido and agression

The Little Blue Pill
Vasodilation and Constriction
Viagra inhibits Phospho-di-esterase type 5 (PDE5)
PDE5 is only in the penis
“Classical” Popper [for heart attacks]
Rush, Ram, Thrust, Rock Hard, Hix, TNT, Liquid Gold
Chemistry of Nitro-compounds
Subjective Reports of Orgasm
M&J

* Stage I: Sensation of ejaculatory inevitability; 2-3 seconds; “feeling the ejaculation is coming.”
* Stage II: Contractile sensation followed by a specific appreciation of fluid volume as it is expelled along the lengthened and distended penile urethra

Objective Reports of Orgasm
M&J
* Stage I: Rhythmic contractions of accessory organs (epididymis, vas deferens, seminal vesicles, prostate); collection of fluid in the prostatic part of the urethra
* Stage II: Relaxation of external sphincter of bladder; fluid flows into distended bulb and penile urethra; regular contractions of penile urethra and penile muscles forcefully expels semen from penis (12-24 inches); 3-4 major regular contractions (0.8 sec) and several more irregular minor contractions.

Involuntary Myotonia in Orgasm
Brain metabolic scans during penile stimulation
Two main areas are activated
One area is deactivated
Male Brain during Orgasm

* Simulation
* Inject tracer
* Measure signal during orgasm at 10 sec intervals
* Map location of signal (increased blood flow)

Brain activation during ejaculation
Ejaculation signal minus Stimulation signal
Male Brain during Orgasm

* Several parts of the brain known to be involved in reward behavior (e.g. heroin pleasure) were activated (meso-diencephalic junction; cerebellum)
* One part was de-activated (amydala/entorhinal cortex) (these parts are activated during fear)
* Very beginnings of study of brain/mind/sex

Relational Male Anatomy
Multiple Orgasm in Males

* “Many males below the age of 30, but relatively few thereafter, have the ability to ejaculate frequently and are subject to only very short refractory periods during the resolution phase.” One of their subjects could ejaculate 3 times in 10 minutes from the onset of stimulatory activity.
* Not quite the same as in the female.. Where the orgasms originate from the plateau phase rather than the resolution phase as in the male.

Does volume of ejaculate matter?
* Subjective reports (M&J, etc.) say yes.
* First orgasm is most intense
* After a period of continence, the orgasm is reported to more intense, and the volume of the ejaculate is highest (on average)
* Very little scientific study

Circumcision and Orgasm
* Can the uncircumcised male exercise ejaculatory control more effectively than the circumcised male?.... The exposed glans in the circumcised male is assumed to be more sensitive.
* M&J found in controlled neurological testing that there was no difference in sensitivity of the glans in either case

A G-spot for the Male?
* The prostate is sensitive to sexual stimulation
* Located adjacent to rectum; surrounds urethra
* Urethra can be erogenous zone for males

Vibrators
Prostate/Anal Stimulation
Questions to think about
* Why do humans have orgasms?
* Why do the French call orgasms “La petite mort” ?
* Can males have orgasms without ejaculation?
* What are the variables that can effect orgasmic satisfaction? Same for males and females?

Orgasm in the Male.ppt