psych 210 CH. 3 male bodies

semen (ejaculate)

-30% prostatic fluid, 70% seminal fluids, <1% sperm -thick, cloudy and off white

circumcision

-5-10 min procedure on infant after brith -weak benefits but reduces HIV and HPV transmission -rate of procedure declining (bc the procedure is done on a baby, unnecessary...)

penis size

-males more unsatisfied with own than females are of male partners -role of media and masculinity (especially from porn, social media - unrealistic images) -diversity exists across all males and every penis size

prostate cancer

-males over 50 -highly treatable if detected early, five year survival rate ~ 99% -it is the most common type of non-skin cancer in males -symptoms: difficulty urinating, blood in urine or blood, pain in lower back and hips -detectable by routine digital rectal exam (is the prostate enlarged), blood tests for PSA -treatment: remove prostate/nearby lymph nodes, radiation therapy, testosterone blocking drugs

benign prostatic hyperplasia (enlarged prostate)

-males over 60 -prostate continues to grow through adult life, can constrict urethra as it passes through prostate causing weak urine flow, urgency and high frequency in urination

nocturnal erections

-phenomenon that is thought to begin in utero -may help oxygenate penile tissue and maintain elasticity by continuously pooling blood in and out of penis -occurs during REM, when dreams occur -dreams do not need to be erotic, occur 3-5 times a night

bulbourethral glands (cowpers glands)

-two pea sized glands located below prostate gland -secrete pre-cum which appears at tip of penis @1 min prior ejaculation, does not contain sperm but can still lead to pregnancy -help neutralize the naturally acidic environments of male's urethra and vagina to ensure viability of sperm

accessory sexual structures

1. anus: same nerve supply as in genitals, dilates in response to stimulation, contracts during orgasm, highly tearable (no lubrication), highly capable of transmitting STIs 2. perineum: bw base of penis and anus, some are aroused by erotic touch 3. nipples: response varies, can have additional nipples

4 parts to sperm

1. head: nucleus 2. flagellum: tail that propels it forward 3. acrosome: surrounds top of head, receptors and enzymes that facilitate fertilization of ovum 4. midpiece: part of flagellum closest to head, tightly wound with mitochondria (energy supply for sperm)

process of ejaculation

1. prior to emission, fluids from vas deferens, seminal vesicles and prostate gland are expelled into urethra = semen 2. urethral sphincter at base of bladder constricts, preventing back flow and forcing semen out of body 3. once emission begins, it is experienced as an inevitable pulsing sensation at base of penis, each burst squeezes semen from urethra that decrease in instensity

process of ejaculation (more concise)

1. sperm travels up from base of vas deferens 2. sperm are pushed around the top of bladder 3. sperm are mixed with seminal fluid in the ejaculatory ducts 4. sperm is mixed with fluid from prostate gland 5. semen is emitted through the urethra and out of penis

corpus spongiosum

ENLARGES during erection, contributing to its SIZE

corona

a rim of tissue that encircles the glans

inguinal canal

a tube that connects the spermatic cord through the abdominal wall and into the groin

ischiocavernosus muscle

affects angle of male's erection and allows for voluntary movement of penis when it is erect

autonomic nervous system

all genital receptors relevant to erection are triggered by a spinal reflex

priapism

an erection sustained for a long time in the absence of stimulation -can cause damage bc tissue in penis has no blood flow

erection

arteries in corpora cavernosa open and blood pools in

lumen

as sperm mature, the migrate into these tubes

variocele

causes the veins in the testicles to swell and feel like "a bag of worms"

urethra

center of shaft, double function: discharge urine and semen -sterile

shaft

contains three structures bound together by connective tissue

most erotically sensitive areas of the penis

corona and frenulum

epididymis

curved structure that attaches to the bottom and top surface of testicle -where mature sperm migrate from lumen -sperm remain here for about a week until they form a paste like mass -sperm can partially move during this period

viagra

drug used to treat erectile dysfunction

phimosis

foreskin cannot be retracted/pulled back to expose glans

paraphimosis

foreskin is trapped behind corona and cant be pulled back over the glans

Interstitial cells

found between seminiferous tubules, produce testosterone

prostaglandins

found in high concentration in sperm hormones that act as chem messengers also present in females

on its own, seminal fluid contains...

fructose and prostaglandins

vasocongest

grow erect

glans

head of penis

genital end-bulbs

highly concentrated sensory nerve endings that are responsive to tactile stimulation during sex -dense around corona and frenulum

function of the scrotum

holds the testicles

orchitis

inflammation of the testicle that frequently co-occurs with epididymitis

ejaculatory ducts

left and right seminal vesicles combine to the right and left vas defentia -here sperm mix with fluid from seminal vesicles

corpora cavernosa

lie on either side of penis, HARDEN during arousal, CONTROLS ANGLE of erection for penetration

prostate gland (paraurethral gland)

located in the midline of male body, below bladder, equivalent of Skene's gland in females -sperm (plus seminal fluid) mixes with prostate fluid as it passes from ejaculatory duct through prostate -prostate fluid is 30% of semen

spermatic cord

loose bundle of structures that connect each testicle to important internal organs

foreskin

loose fold of skin partially covering the glans in an uncircumcised penis

frenulum

looser skin created when the corona moves on the underside of penis

cremaster muscle

muscle that wraps around the spermatic cord and is a sling for the testicles KEEPS SPERM AT IDEAL TEMP

bulbospongiosus and pubococcygeus muscles

muscles involved in orgasm and ejaculation

prostatis

non-cancerous, can be chronic or acute -inflammation of prostate, pain during ejaculation/urination, can lead to pain in lower back or pelvis -usually caused by UTI

scrotum

part of male external genitalia -contains two testicles

prostate gland releases fluid that...

prevents semen from coagulating

spermatogenesis

process that prouduces sperm

function of testicles

produce sperm and sex steroids

seminal vesicles

reside directly behind bladder contain no semen secrete a fluid that contains fructose (a sugar) as well as prostaglandins, which enable the motility and viability of sperm fluid from here makes up 70% of semen

penile bulb

rounded mass of erectile tissue formed by corpus spongiosum at the end of the penis (closest to male's body)

ejaculation (emission)

series of rhythmic contractions of the muscles surrounding urethra and pelvic floor

vas deferens

sperm are stored here until ejaculation

epididymitis

swelling of testicle due to an infection often caused by an STI or other bacteria

hydrocele

swelling of the testicle due to collection of fluid around membranes of testicle

balantis

swollen glans as a result of infection

testicular cancer

symptoms include lump in testicle and maybe pain in lower abdomen

mechanics of erection

tiny spaces called sinusoids inside the corpora cavernosa fill with blood during erection, veins of penis that carry blood out, close, allowing pinis to vasocongest and grow erect (when penis is flaccid, arteries leading into sinusoids are blocked)

vas deferens

tube within the spermatic cord which carries mature sperm up from the testicles

peyronie's disease

unnatural curvature of the penis usually due to scar tissue

seminiferous tubules

very fine and twisty networks of tubules inside the testicle, WHERE SPERM DEVELOPMENT BEGINS

crura

where two corpora cavernosa diverge in the penile bulb