sexology week 2

clitoris, mons pubis, inner lips, outer lips, vaginal opening

vulva

* external female genitals

clitoris

sensitive organ exceptionally important in sexual response

* tip (glans)
* 2 corpora cavernosa
* 2 crura
* vestibular bulbs

tip (glans)

externally front of vaginal opening and urethral opening

homologous organs

male and female sex organs are __

* develop from same tissue before birth

homologous similarities

* develop from same embryonic tissue
* both have corpora cavernosa
* both vary in size depending on person
* both are erectile
* rich in nerve ending supply

no reproductive function

clitoris only important function is producing sexual arousal

outer lips

pads of fatty tissue lying along both sides of vaginal opening

inner lips

folds of skin lying between outer lips and running along edge of vaginal opening

clitoral hood

formed by inner lips coming together in front

bartholin glands

2 tiny glands located on either side of vaginal entrance

* no sig function

fourchette

place where inner lips come together behind vaginal opening

perineum

area of skin between vaginal opening and anus

introitus

vaginal opening is called

urethra

where urine passes

* separate opening

hymen

thin membrane partially covering vaginal opening

* at first intercourse, may be broken or stretched

vagina, vestibular bulbs, Skene’s glands, uterus, ovaries, fallopian tubes

internal sex organs of female consist of:

3 layers of vagina

1. vaginal mucosa (inner layer)
2. muscular (middle layer)


1. covering (outer layer)

lower 1/3 near introitus

where the nerve supply of vagina is mostly

* sensititivity to erotic stimulation

inner lips, outer lips, clitoris

very sensitive to stimulation

pubococcygeus muscle

stretched or weak muscle during childbirth

\

vestibular bulbs

pea pod-sized organs (2)

* near entrance, under inner lips
* erectile tissue

Skene’s glands (female prostate)

between urethra opening and vaginal wall

* secretion area similar to male prostate fluid
* G-spot: female ejaculation

uterus

womb

* upside-down pear
* held in place by ligaments
* 3 layers

cervix

narrow lower third of uterus

* opens into vagina

fundus

main part of uterus

* top

os (cervical canal)

entrance to uterus through cervix

* narrow

endometrium, myometrium, perimetrium

3 layers of uterus

endometrium

(uterus layer) rich supply of glands and blood vessels

* state varies with age and menstrual cycle

myometrium

(uterus layer) muscular

* strong and elastic muscles
* powerful contraction of labor and orgasm

perimetrium

(uterus layer) external cover

ovaries

almond-sized oragns

* on either side of uterus
* produce eggs (ova)
* make estrogen and progesterone

breasts

* not sex organs
* 15-20 clusters of mammary glands each with separate opening to nipple and fatty, fibrous tissues

small breasts

more erotically sensitive per square inch than larger one because both have same number of nerve endings

glans (male)

tip of penis

shaft

main part of penis

meatus

urethral opening of penis

corona

raised ridge at edge of glans

* most sexually excitable with the rest of glans

scrotum

loose pouch of skin that contains testes

* part of internal genitals

supercision

making a slit the length of foreskin on top with foreskin remaining intact

* done in many parts of Polynesia

subincision

slit made on lower side of penis alongs entire lengths and to depth of urethra

* done in some Australian tribes

13 cm long and 11-12 cm circumference

average sized erect penis

testes

gonads (analogous to ovaries)

* make germ cells (sperm) and sex hormones (testosterone)

seminiferous tubules

internal structure of testes

* make and store sperm

interstitial cells

produce testosterone

* found in connective tissue lying between seminiferous tubules

cremasteric reflex

reflex contraction of cremaster muscle pulls testes up or down

heat

sperm can be damaged by this

spermatogonium

earliest stage of germ cell maturation

spermatogonium, spermatocyte, spermatid

germ cell maturation

spermatozoan

another word for sperm, or fully mature germ cell

200 million sperm cells

average ejaculate contains

secretions of prostate

sperm becomes active when mixed with

seminal vesicles

above prostate

* produce 60% of seminal fluid (remaining 40 by prostate)

cowper’s glands

just below prostate and empty into urethra

* during arousal, secrete small amount of clear alkaline fluid (like drops before ejaculation)

neutralise acidic urethra

* safe passage of sperm

why cowper’s glands secrete alkaline fluid right before ejaculation

genetics, menopausal hormone therapy, obesity

most common causes of breast cancer (12% of US women)

BRCA1 and BRCA2

mutations on these genes create high risk of breast cancer

* increase susceptibility to ovarian cancer

cysts

fluid-filled sacs

fibroadenomas

benign (non-cancerous) breast tumors made up of both glandular tissue and connective tissue

malignant tumours

cancerous tumour

needle aspiration

determine if lump is a cyst or tumour

lumpectomy

lump and small bit surrounding tissues are removed

simple mastectomy

breast and maybe few lymph nodes are removed

modified radical mastectomy

breast and underarm lymph nodes are removed

radical mastectomy

entire breast, underlying pectoral muscle, uderarm lymph nodes are removed

cervical, endometrial, ovarian cancer

most common after breast cancer

hpv

causes 90% of cervical cancer c

cryotherapy, biopsy

treatment of non-advanced cervical cancer

hysterectomy, radiation therapy

treatment of advanced cervical cancer

endometrial cancer

suspected if vaginal bleeding when not on her period

hysterectomy

removing uterus surgically

oophorectomy

surgical removal of ovaries

prostate cancer

pressure of prostate tumour on urethra causes difficulty in urination

cancer of testes

most common in young men

* painless lumps testes
* pain in lower abdomen/groin

gonads

testes and ovaries

follicle-stimulation hormone, luteinizing hormone

pituitary produces these hormones that affect testes functioning

sperm production

FSH controls

testosterone production

LH controls

GnRH

hypothalamus produces

* regulates LH levels n

negative feedback loop

HPG axis

hypothalamus, pituitary and testes

* maintains constant testosterone levels

inhibin

hormone produced by testes

* regulates FSH levels in HPG axis
* male contraceptive

estrogen

stimulated by LH in females

* induces puberty changes
* maintains mucous membranes in vagina
* stops growth of bone and muscle

progesterone

stimulated by FSH in females

* \

prolactin

stimulates secretion of milk after giving birth

* secreted by pituitary

oxytocin

stimulates ejection of milk, contractions during childbirth, promotes bonding

* secreted by pituitary
* produced in both sexes

only testosterone levels

estradiol, progesterone and testesterone levels

* which of these differ between sexes

cryptorchidism

one or two of testes may not descend

* 3% of males

homologous

when organ in males and organ in females both develop from same embryonic tissue

analogous

when 2 organs have similar functions

intersex condition

disorder of sex development

* reproductive structures aren’t developed correctly
* 2% of births

congenital adrenal hyperplasia (CAH)

genetic female develops ovaries as a fetus but later during prenatal development, adrenal glands function abnormally and produce excess amount of androgens

androgen-insensitivity syndrome (AIS)

46XY chromosomes

* male gonads and hormone profile
* external female genitals
* infertile

Adrenogenital syndrome (AGS)

46XX chromosomes

* female internal genitals
* clitoris hyperplasia (looks like a penis)
* high T levels

menarche

first menstruation

* only able to become pregnant 2 years later once ovulation begins

percentage of body fat hypothesis

body fat increases → leptin levels rise → stimulates secretion of kisspeptin hormone → stimulates hypothalamus, produce more GnRH → LH and FSH production → estrogen production rises → puberty

adrenarche

time of increasing secretion of adrenal androgens

* beginds before 8

gynecomastia

breast enlargement in boys (temporary)

* 80% experience

estrous cycle

non/only slight bleeding

* ovulation in “heat”
* dogs and horses
* engage in sexual behav only during estrus phase of cycle

follicular phase (day 5-13)

high levels of estrogen stimulate endometrium of uterus to grow, thicken, form glands (proliferation)

ovulation (day 14)

sudden surge in LH causes the ovary to release egg.

luteal phase (day 15-28)

progesterone stimulate endometrium glands to start secreting nourishing substances

* no preg: estrogen level declines sharply = uterine line sheds (=menstruation)