Repro review Flashcards
what does the round ligament of the uterus connect?
the uterus with the labia majora
what investigations can be used if external genitalia ambiguous at birth?
hormonal tests
gonadal sex
karyotyping
anatomy e.g. gonad palpation, length and diameter of any phallus (penis), urethral meatus position
determination of gonadal sex?
presence/absence of Y chromosome which has an SRY gene on its short arm= sex-determining region of Y chromosome
if a Y chromosome is present in the germ cells, testes will always be produced
In turner’s syndrome, ovaries develop normally until 15th wk of gestation, ova then begin to degenerate and disapperar, what may be presentation at puberty?
short stature
primary amenorrhoea
poor breast development
what gonads would be produced if sex chromosome mosaic of XY,XX (or XO) cells?
both male and female gonadal tissues
This is true/primary hermaphroditism, but has not been described in humans
how is spontaneous development of female genitalia stopped in male?
MIH secretion from sertoli cells
testosterone secretion from leydig cells from 9wks gestation
what does the prostate develop from?
urogenital sinus, formed from division of cloaca
what does the vagina develop from?
upper part from paramesonephric ducts
lower part from urogenital sinus
what do the urethral folds give rise to in the male?
ventral aspect of shaft of penis, including the spongy urethra
example of a disorder of sex development where the genotypic (chromosomal) sex does not match the phenotype- physical appearance?
congenital adrenal hyperplasia
characteristics of a patient with androgen insensitivity syndrome?
patients are male with Y chromosome and testes, BUT lack of androgen receptors or failure of tissues to respond to receptor-dihydrotestosterone complexes, so androgens ineffective at inducing differentiation of male genitalia.
PM system suppressed by MIH from testes, so no uterine tubes or uterus.
Ambiguity of external genitalia as dihydrotestosterone necessary for fold fusion of genital swellings to form scrotum, and urethral folds to form ventral aspect of shaft of penis and penile urethra
outcome of dihydrotestosterone lack in a male during sexual development?
external genitalia do not develop normally as this hormone causes fusion of LS folds and urethral folds, so they may appear male but be underdeveloped with hypospadias- urethral fold fusion incomplete with abnormal openings of urethra along inferior aspect of penis, on ventral surface, or they may appear to be female with clitoromegaly.
symptoms of Klinefelter’s (47, XXY)?
reduced fertility
small testes
reduced testosterone gynecomastia
commonly result of nondisjunction of XX homologues
Gonadal dysgenesis- oocytes absent, ovaries appear as streak gonads as comprise mainly fibrous tissue, occurs in Turner’s, what are the symptoms?
webbed neck short stature shield-like chest cardiac and renal anomalies inverted nipples
how may a bifid penis occur?
splitting of genital tubercle
what is epispadias?
urethral meatus found on dorsum of penis
assoc with exstrophy of bladder and abnormal closure of ventral body wall
what is a bicornate uterus and how does it occur?
uterus has 2 horns entering a common vagina
result of incomplete fusion of paramesonephric ducts
how do germ cells reach the indifferent gonad?
diploid cells originate from epiblast and arise in the yolk sac, then migrate along doral mesentery into retroperitoneum to enter gonadal ridge
what is mullerian agensis?
characterized by a failure of the müllerian duct to develop, resulting in a missing uterus, fallopian tubes, and variable malformations of the upper portion of the vagina
why does cryptorchidism occur?
gubernaculum fails to develop or fails to pull testes into scrotum
reflection of androgen abnormalities
changes to spermatids to form spermatozoa?
cell elongation
flagellum formation
organelle reorientation
cytoplasmic removal
How much body weight does brain account for at birth
12%
difference between anterior pituitary and hypothalamus, where does A pituitary arise from?
A pituitary= endocrine gland
hypothalamus= nervous tissue
A pituitary arises from Rathke’s pouch
summarise target tissues and actions of FSH, LH, TSH, ACTH, MSH, GH and prolactin
Gonads Growth of reproductive system
Gonads Sex hormone production
Thyroid Gland Secretion of thyroid hormones
Adrenal Gland Secretion of glucocorticoids
Melanocytes in Skin and Hair Production and release of melanin
Liver, adipose tissue Promotes growth, lipid and carbohydrate metabolism
Ovaries, mammary glands Secretions of oestrogen, progesterone, milk production
common causes of early puberty in boys?
CAH
pineal tumours
meningitis
how could puberty be delayed?
androgen receptor blockers
treat underlying condition e.g. CNS lesion
drugs to inhibit anter. pituitary gonadotropin secretion
what adrenal gland disorders may cause virilisation in males but no more development?
congenital adrenal hyperplasia- adrenal hyperfunction due to enzyme deficiency
adrenocortical tumour
how can CAH and adrenocortical tumour be differentiated between?
CAH- high level of 17-hydroxyprogesterone
US then CT for tumour, biopsy if imaging shows tumour
effects of oestrogen depletion that menopausal women might experience?
hot flushes poor sleep vaginal/urethral atrophy dysparenuria, dysuria breast atrophy mood changes/depression OP changing cholesterol/lipid profile, poss increased CHD risk
tments for menopause problems?
HRT- oestrogen or combined
calcium
function of progesterone administered in addition to oestrogen in HRT to women not having had a hysterectomy?
reduce risk of endometrial cancer as progesterone inhibits proliferation of uterine lining stimulated by oestrogen
why do fibroids regress after the menopause?
they are hormone dependent
how are fibroids diagnosed?
US
bimanual examination
how to assess menstrual blood loss?
pad and tampon counts, and measure HB/haematocrit levels
menstrual loss defining menorrhagia?
> 80ml, which will lead to anaemia
non-surgical approach of treating menorrhagia?
GnRH agonist
surgical approach of treating menorrhagia?
endoscopic resection or abdom. myomectomy or hysterectomy
describe how hormones from hypothalamus reach anter pituitary to exert their action?
releasing hormones neurosecreted from median eminence of hypothalamus and travel to A pituitary in hypophyseal portal circulation, so don’t need to prod a lot as travel directly in a small amount of blood for a short distance, so are not diluted before exerting their action
testosterone in medium to long term is constant as spermatogenesis occurs continuously, but how do its levels vary?
circadian rhythm- highest in early morning
effects of environ stimuli e.g. light/dark
what causes variation in reproductive cycle length?
variation in timing of ovulation- affected by environ e.g. stress
when is a common time for miscarriage and why?
10-14 wks as support of pregnancy changing from CL to placenta
how is cervical mucus made receptive to sperm transport?
oestrogen action on cervical glands
what is the contraceptive action of oestrogen?
acts by -ve feedback to inhibit FSH release and hence prevent follicle development
when is the 1st meiotic division of the oocyte completed?
following the LH surge, with LH acting on LH receptors present on the granulosa cells following the action of oestrogen
which muscle extends between the perineal body and the ischial ramus?
superficial transverse perineus
what is the lateral fornix of the vagina closely related to?
the ureter
muscles forming lateral wall of pelvic cavity?
obturator internus
piriformis- also forms posterior wall
what forms inferior part of pelvic cavity?
pelvic floor/diaphragm= levator ani and cocyygeus (ischio)
how is the pelvic cavity separated from the perineum?
by the pelvic floor
2 holes of significance in structure of pelvic floor?
UG hiatus= situated anteriorly, allows passage of urethra and vagina in females
rectal hiatus= centrally positioned for passage of anal canal
what lies between the UG hiatus and the rectal hiatus?
perineal body
3 roles of pelvic floor muscles?
maintain urinary and fetal continence
support of abdominal and pelvic viscera
resistance to increase in intra-pelvic or abdominal pressure
levator ani attachements?
pubic bones anteriorly
thickened fascia of obturator internus laterally (tendinous arch)
ischial spines posteriorly
main function of puborectalis?
maintain fecal continence
what attaches to perineal body located midway between ischial tuberosities?
fibres of levator ani
bulbospongiosus
superficial transverse perineus
anal sphincters
coccygeus muscle innervation?
A.rami of S4 and S5
course of coccygeus muscle?
It originates from the ischial spines and travels to the lateral aspect of the sacrum and coccyx, along the sacrospinous ligament.
anatomical borders of perineum?
Anterior – Pubic symphysis.
Posterior- The tip of the coccyx.
Laterally – Inferior pubic rami and inferior ischial rami, and the sacrotuberous ligament.
Roof – The pelvic floor.
Base – Skin and fascia.
The perineum can be subdivided by a theoretical line drawn transversely between the ischial tuberosities. This split forms the anterior urogenital and posterior anal triangles. These triangles are associated with different components of the perineum
components of urogenital triangle? (anterior part of perineum, separated from posterior by imaginary line between ischial tuberosities)
deep perineal pouch perineal memebrane superficial perineal pouch deep and superficial perineal fascia skin
in which pouch are bartholin’s glands located?
superficial perineal pouch
in which pouch are bulbourethral glands located?
deep perineal pouch
why can vaginal delivery in childbirth cause pelvic floor dysfunction?
damage to levator ani muscles forming pelvic floor
damage to perineal body
stretching of pudendal nerve which innervates pelvic floor muscles
stretching of ligaments which support the muscles
why might removal of prostate lead to impotence?
autonomic nerves supplying erectile tissues in perineum pass around sides of prostate in pelvis so may be damaged
3 ways baby could be delivered with help?
ventouse delivery
forceps
caesarean section
A patient has primary amenorrhoea and anosmia, what is the likely cause?
Kallman syndrome: genetic defect producing hypogonadotropic hypogonadism in which fetal GnRH neurosecretory neurones fail to migrate normally from the olfactory placode to the medial basal hypothalamus so olfactory bulb doesn’t develop properly
2 most common causes of gonadal dysgenesis?
Klinefelter’s syndrome: testes have a limited capacity to secrete testosterone so low, high FSH and LH due to -ve feedback lack, and so oestrogen prod. proportionally increased produced gynaecomastia
Turner’s syndrome: streak gonads as ovaries replaced by fibrous tissue
risks associated with pre-term birth?
cranial sutures too wide open so pressures of birthing process fail to result in interlocking of cranial bones, so high probability of brain damage in birthing proocess
insufficient surfactant production so susceptibility to respiratory distress syndrome
whens does surfactant prod begin in newborn and when is it markedly increased?
around wk 20
increased after wk 30 when alveoli open in a significant number and SA dramatically increases
why is neonatal jaundice not uncommon?
neonate may not be able to immediately deal with bilirubin after birth as this function was not carried out in utero as fetus unable to excrete bilirubin via gut so remained unconjugated and passed across placenta into maternal circulation
what happens as a result of continued swallowing of amniotic fluid by fetus?
fetal gut absorbs water and electrolytes leaving debris to accumulate together with debris from developing gut in fetal large bowel= MECONIUM- usually only excreted by fetus in distress e.g. fetal hypoxia
when does amniotic fluid reach maximum?
38 wks at 1 litre
where is amniotic fluid derived from in early pregnancy?
by dialysis of fetal and maternal EC compartments with some exchange occurring across fetal skin
when do thalamo-cortical projections reach maturity?
wk 29
what can be measured to assess liver’s functioning in fetus to store glycogen?
fetal abdominal circumference
average birth weight at term in england?
3.5kg
below 2.5 is considered low birth weight
what is the obstetric conjugate?
distance between the sacral promontory and midpoint of PS= narrowest fixed distance the fetal head must pass through during delivery (10.5cm)
why can the obstetric conjugate not be measured directly?
due to presence of the bladder
what is measured instead of the obstetric conjugate prior to labour to assess the female pelvis in pregnancy?
diagonal conjugate: distance from the sacral promontory at the level of the ischial spines to the inferior border of the PS
this is 1.5-2cm longer than the obstetric conjugate
diameter of mid-cavity between pelvic inlet and outlet?
12cm, circular