Sexual anatomy (female) Flashcards
Female external genital organs
Organs collectively known as the vulva
- clitoris
- mons pubis
- inner lips
- outer lips
- vaginal opening
–> appearance of the vulva varies greatly
Clitoris
A higly sensitive organ that is exceptionally important in the female sexual response
- Tip: a knob of tissue externally in front of the vaginal opening and urethral opening
- shaft: consists of two corpora cavernosa
- Crura: two longer spongy bodies that lie deep in the body and run from the tip to either side of the vagina
Mons pubis
Fatty pad of tissue under the pubic hair
Outer lips - labia majora
Rounded pads of fatty tissue lying along both sides of the vaginal opening, covered with pubic hair
Inner lips - labia minora
Two hairless folds of skin lying between the outer lips and running right along the edge of the vaginal opening
Bartholin glands
Two tiny glands located on either side of vaginal entrance
Perineum
The skin between vaginal entrance and anus
Introitus
The vaginal entrance
Urethra
The tube through which urine passes from the bladder out of the body
Hymen
A thin open membrane which, if present, partially covers the vaginal opening. For gyneachologists it defines the border between outer and inner anatomy
- one of a number of different types
- generally has some openings
- also called cherry or maidenhead, but it is not a sign of virginity
Internal genital organs of the female
- vagina
- vestibular bulbs
- Skene’s gland
- uterus
- pair of ovaries
- pair of fallopian tubes
Vagina
The tube-shaped organ into which the penis is inserted during coitus and through which a baby passes during birth
- at the bottom it ends in the vaginal opening (introitus)
- muscles surrounding it are the pelvic muscles
Pubococcygeus muscle
A muscle around the vaginal entrance that is stretched during coitus
- surrounding the vagina, urethra, and anus is a set og muscles called the plevic floor muscles
Vestibular bulbs - clitoral bulbs
Erectile tissue running under the inner lips
Skene’s gland - female prostate
Glnd located on the front wall of the vagina with ducts that empty into the urethra
- in some women, secreted fluid that is buochemically similar to male prostate fluid
Uterus
The organ in which the fetus develops
- endometrium
- myometrium
- perimetrium
Cervix
The lower part of the uterus, which opens to the vagina
Endometrium
Sloughed off at menstruation, creating the menstrual discharge
Myometrium
A muscular but highly elastic middle layer that creates the powerful contractions of labor and orgasm
Perimetrium
The external cover of the uterus
Fallopian tubes - oviducts
The tubes extending from the uterus to the ovaries
- pathway by which the egg travels toward the uterus and the sperm reach the egg
- extremely narrow; lined with hairlike projections called cilia
–> fertilization typically occrs in the section closest to the ovary called the infundibulum
- ends in fimbriae, fingerlike projectios that extend to the ovary
Ovaries
Two organs about the size and shape of unshelled almonds, lying on either side of the uterus
- contain eggs (ova)
- manufacture the sex hormones estrogen and progesterone
- contains numeorus follicles, each a capsule that surrounds an undeveloped egg
The breast
Each breast consists of 15 or 20 clusters of mammary glands, each with a separate opening to the nipple, surrounded by fatty and fibrous tissues
- at the tip is the nipple, into which the milk ducts open
- darker area surrounding the nipple is the areola
Female Genital cutting
- FGC
- hemorrhaging: doodbloeden
- infecties: tetanus, hepers, BV, HIV an hep. B
- urineweginfecties
- pijnlijke seks
- ernstige complicaties tijdens de bevalling
Hormones
Chemical substances manufactured by the endocrine gland; secreted directly into the bloodstream but also with paracrine activation
- testosterone
- estrogen
- progesterone
Hypothalamus-hypofyse-gonad feedback loop
Hypothalamus –> hypofyse –> gonaden
Follikel Stimulerend Hormoon FSH
Produceert follikel/blaasjes waarin het eitje zich bevindt. Dit wordt steeds groter en groter zodat het eitje kan rijpen en loslaten van de eierstokken
Luteinizing hormoon LH
Wanneer er in een piekniveau is binnen de menstruele cyclus, zal binnen 24-48 uur het follikel openbarsten en het eitje vrijkomen
Estrogen
Predominant in first half of menstrual cycle
Progesterone
Predominant in second half cycle and early pregnancy
Prolactin
Stimulates production of milk by the mammary glands
Oxytocin
Stimulates contractions of the uterus during childbirth, promotes ejection of milk from nipples and promotes affection
Estrogen and progesterone are important
- ovaries produced
- Estrogen brings about many of the changes of puberty, maintains the mucous membranes of the vagina, and stops the growth of bone and muscle in females
- Levels of estrogen and progesterne fluctuate according to the phases of the menstrual cycle, pregnancy and menopause
–> FSH and LH in the female regulate the levels of estrogen and progesterone; and inhibit FSH production
Prolactin and oxytocin
- pituitary produced
- Prolactin stimulates production of milk after a birth
- Oxytocin stimulates ejection of milk from the nipples, stimulates contractions of the uterus during childbirth and promotes affectionate bonding
- Note oxytocin is produced in both males and females
- Levels of estradiol and progesterone do not differ between adult men and women; only testosterone levels differ, with men having more
Fluctuations in sex drive for women
- Some found a peak frequency of intercourse around ovulatio
- otehers found peaks just before and just after menstruation
- one study indicated that sexual activity initiated by the woman peaked during the three days before and three days after ovulation
Cycles in men
Traditional assumption is that men do not experience monthly cycles
- men’s testosterone levels displayed weekly fluctuations
- men with a female partner and who wished to have a child dipsplayed a 28-day cycle of testosterone levels
- men who had sex with an unfamiliar partner showed a 100 percent increase in testosterone levels the following morning
Sex chromosomes
Specific sec chromosomes carried in a fertilized egg are the deciding factor in whether it will become a male or a female (XX = female; XY = male)
- in the 7th week after conception, basic structures have formed. Sex chromosomes direct various organs to begin differentiation
Klinefelter’s syndroom
XXY –> de man heeft kleine testikels, er wordt geen sperma geproducerd en testosteronwaarden zijn laag+
Gonads
In males the undifferentiated gonads develop into testes at 7 weeks. In females they develop into ovaries at 13-14 weeks
- on the Y chromosome, SRY, causes manufacture of testis-determining factor (TDF), and male development occurs
- SRY: sex determining region, Y chromosome
Müllerian ducts
In females turn into the fallopian tubes, the uterus and the upper part of the vagina
- Tubercle becomes the cliteris, the flods become the inner lips and the swelling develops into the outer lips
Wolffian ducts
In males supported by testosterone, turn into the epididymis, the vas deferens and the ejaculatory duct
- Tubercle becomes the glans penis, the folds form the shaft of the penis, and the swelling develops into the scrotum
Descent of the testes and ovaries
- Ovaries and tested are not from Mullerian or Wolffian origin
- Ovaries and testes change shape and position as developmental changes take place
- Ovaries travel from higher intra-abdominally to pelvis
- Testes travels from near the top of the abdominal cavity down into the scrotum via the inguinal canal –> cryptorchidism (undescended testes)
Brain differentiation
During the prenatal period, sex hormones act on the brain
- if testosterone is present during fetal development, estrogen receptors in the hypothalamus become insensitive to estrogen
- if estrogen is present, they ebcome highly sensitive to levels of estrogen in the bloodstream
Plasticity of the brain: constant changes in response to experiences
Epigenetics
A funtional change to DNA that does not alter the genetic code itself, but leads to changes in gene expression
- Prenatal sexual differentiation of the brain may involve epigenetic factors that can lead genes to be expressed or silenced
- just a few brain structures show gender differentiation
- neuroscientists emphasize the plasticity of the brain, which is constantly changing in response to experience
Atypische prenatale genderdifferentiatie
- Chromosomaal gender : XX, XY
- Gonaal gender: testes, ovaries
- prenataal hormonaal gender (testosteron in mannen) en prenatale en neonatale hersendifferentiatie (testosteron bij masculinisatie)
- interne organen
- extern genitaal uiterlijk
- pubertaal hormonaal gender
- toegewezen gender
- genderidentiteit
Congenital adrenal hyperplasia CAH
Bij een genetische vrouw ontwikkelen de eierstokken zich normaal en wordt er een overschot aan androgenen geproduceerd.
- lijken op man, maar is vrouw
Androgen-insensitivity syndrome AIS
Een genetische man produceert normale testosteronniveaus, maar het weefsel is hier ongevoelig voor, waardoor prenatale ontwikkeling gefeminizeerd wordt. De genitaliën lijken op die van een man
Puberty
The time during which there is a sudden enlargement and maturation of the gonads, other genitalia and secondary sex characteristics, leading to reproductive capacity
Adolescence
A socially defined period that bears some relationship to puberty
- psychological transition from the behavior and attitudes of a child to the behavior, attitudes and responsibilities of an adult
- does not exist in some cultures
Puberty in girls
Includes: breast dvelopment, growth of pubic hair and increased body growth
- Estrogen eventually stops the growth spurts in grls, sooner than in boys, accounting for women’s lesser average height
- first menstruation 12-13 years of age (leptine en kisspeptine)
Leptine
Is gerelateerd aan de start van de puberteit en lichaamsvet. Een meisje gaat pas menstrueren als ze een bepaald percentage lichaamsvet heeft
Kisspeptine
Stimuleert de hypothalamus om meer GnRH aan te maken, waardoor LH en FSH gestimulerd worden en de eierstokken oestrogeen gaan aanmaken
Puberty in boys
- growth of testes scrotal sac
- growh of pubic hair
- penis enlarges
- growth of facial and auxiliary hair
- erections increase in frequency
- voice drops or changes
- increased body growth
Menstrual cycle
Menstrual cycle is regualted by fluctuating levels of sex hormones, which produce certain changes in the ovaries and uterus
- humans are nearly unique among species in having a menstrual cycle
- other species of mammals has estrous cycle: heat
4 phases of the menstrual cycle
- Follicular phase
- Ovulation
- Luteal phase
- Menstruation
Pollicular phase
- proliferative
Just after menstruation, an egg matures in preparation for ovulation
- FSH is secreted to stimulate follicles in the ovaries
- One follicle begins to ripen and brings an egg to maturity
- Follicle secretes estrogen, stimulation growth of the endometrium
Ovulation
Follicle ruptures, releasing the mature egg
- estrogen inhibits FSH production and stimulates the hypothalamus to produce GnRH, which causes the pituitary to begin production of LH
Luteal phase
- secretory
After releasing an egg, the follicle turns into a glandular mass of cells called the corpus luteum, which manufactures progesterone
- Corpus luteum continues to produce estrogen and progesterone for 10-12 days
- If pregnancy does not occur, the hormone output declines sharply and the uterine lining is shed
Menstruation
The endometrium of the uterus is sloughed off in the menstrual discharge
Follicular phase - hormones
High levels of estrogen stimulate the endometrium
Luteal phase - hormones
Progesterone secreted by the corpus luteum stimulate the glands of the endometrium to start secreting nourishing substances
What happens in the uterus during menstrual cycle
- Corpus luteum produces estrogen and progesterone for about 10-12 days
- If pregnancy has not occured, hormone output declines
- menstrual fluid: blood from the endometrium, degenerated cells and mucus from the cervix and vagina
Menstrual cycle: length and timing
Normal menstrual cycle is 20-36 days (avg. 28)
- starts on day 1 for 4-5 days
- follicular phase: 5-13
- ovulation phase: day 14
- luteal phase: 15 untill the end
Mittelschmerz
Some women report that they can feel themselves ovulate in the form of cramping in the lower abdomen
Anovulatory cycle
Menstruation may take place without ovulation
Dysmenorrhea
Painful menstruation
–> prostaglandins is possible cause
Endometriosis
The endometrium grows ina place other than te uterus
Amenorrhea
Absence of menstruation
- Primary: when female has not menstruated by age 18
- Secondary: absence when she has had at least one period
Premenstrual syndrome (PMS)
Severe physical and psychological symptomes, such as depression and irritability, occuring just before menstruation
- Premenstrual dysphoric disorder (PMDD)
- 3-5%, age 35-43
- majority do not eperience fluctuations in mood
