Endocrine and reproductive systems Flashcards
what hormones are released by the hypothalamus?
thyrotropin releasing hormone corticotropin releasing hormone gonadotropin releasing hormone growth hormone releasing hormone prolactin releasing hormone
how are the hypothalamus and anterior pituitary connected?
blood vessels
how are the hypothalamus and posterior pituitary linked?
neurones
what hormones does the anterior pituitary release?
LH FSH Thyroid stimulating hormone prolactin growth hormone
what hormones does the posterior pituitary release?
oxytocin
ADH
testicular function
GnRH causes release of LH and FSH
LH causes leydig cells to release testosterone
FSH activates sertoli cells to carry out spermatogenesis, which also requires testosterone to occur
release of testosterone inhibits production of GnRH and FSH
which cells carry out spermatogenesis?
sertoli cells
which cells produce testosterone?
leydig cells
ovarian function
GnRH released causing LH and FSH to be released which act on ovarian follicles and corpus luteum to produce oestrogen and progesterone
how is the male reproductive tract formed?
Mullerian/ paramesonephric duct degenerates
Wolffian/ mesonephric duct develops into vas deferns, epididymis and seminal vesicles
how is the female reproductive tract formed?
Wolffian/ mesonephric duct degenerates
Mullerian/ paramesonephric duct develops into female fallopian tubes, uterus and upper part of vagina
day 1
fertilisation
acrosome reaction
cortical reaction
zona reactions
day 3
Morula formation
days 1-3 = cleavage
forming 12-16 cells - blastomeres
what are the cells of the morula called?
blastomeres
day 5
blastocyst
blastocoel develops
inner cell mass splits into epiblast and hypoblast
day 6/7
implantation of blastocyst
trophoblast implantation
day 15
gastrulation
invagination of epiblastic cells through primitive streak
bilaminar germ disc becomes trilaminar germ disc
forms mesoderm, endoderm and ectoderm
what are the symptoms of pregnancy?
varicose veins glucose in urine urinary frequency urinary infection breathlessness breast enlargement swollen ankles flushed and hot anaemia
what are the main hormones involved in pregnancy?
hCG progesterone oestrogen human placental lactogen prostaglandins oxytocin relaxin prolactin
what does hCG do?
promotes progesterone and oestrogen secretion by corpus luteum until placenta takes over at 10-12 weeks
detected 10 days after fertilisation to give positive pregnancy test result
what does progesterone affect?
uterus
homeostasis
breast
how does progesterone affect the uterus?
smooth muscle relaxation - preventing fetal expulsion
cervical plug formation which acts as microbial barrier
how does progesterone affect homeostasis?
affects the respiratory centre and cause hyperventilation
affects RAAS system - increasing Na+ reabsorption
how does progesterone affect breasts?
lobular tissue development
inhibits milk production
what does oestrogen act on in pregnancy?
uterus
breast
how does oestrogen affect uterus?
myometrial cell growth
connexin insertion - gap junctions between myometrial cells
inserts oxytocin receptors
causes production of PGE2
how does oestrogen affect the breasts?
breast duct development
inhibits milk production
what does human placental lactogen affect?
mother and fetus
how does human placental lactogen affect mothers?
causes insulin resistance to decrease glucose utilisation and increases blood glucose
lipid break down - increased FFA production
how does human placental lactogen affect fetuses?
promotes growth as more glucose available from mother
what FFAs?
free fatty acids
can move in/ out of cells
what prostaglandins are produced in pregnancy?
PGE2
PGF2-alpha
what does PGE2 do?
softens vcervix
what does PGF2 alpha do?
contracts uterus
what does prolactin do?
breast tissue development during pregnancy
causes milk production post-delivery, previously inhibited by oestrogen and progesterone
what does relaxin do?
softens cervix and pelvic ligaments in preparation for labour and delivery
what does oxytocin do?
causes uterine contraction during labour, inhibited by progesterone during pregnancy
causes milk ejection post-delivery
what is pre-eclampsia?
condition seen after 20 weeks gestation
pregnancy-induced hypertension in associated with proteinuria
what is proteinuria?
protein in urine
what condition should be looked out for when there is hypertension detected during pregnacy?
pre-eclampsia
what are the maternal risks associated with pre-eclampsia?
eclampsia
placental abruption and haemorrhage
what are the foetal risks associated with pre-eclampsia?
prematurity
intrauterine growth retardation
what is intrauterine growth retardation?
condition where unborn baby is growing at a slower rate than it should be
how to treat pre-eclampsia?
labetalol
what does the ductus arteriosus form?
ligamentum arteriosum
what does the foramen ovale form?
fossa ovalis
what does the ductus venosus form?
ligamentum venosum
what does the umbilical vein form?
ligamentum teres
what do the umbilical arteries form?
medial umbilical ligaments
umbilical blood vessels
1 umbilical vein and 2 umbilical arteries
what changes occur at birth?
first breath causes pO2 to rise leads to pulmonary vasodilation right heart pressure falls foramen ovale closes venous blood goes to lungs causing pO2 to rise
what blood group are universal acceptors?
AB positive
what blood group are universal donors?
O negative
rhesus disease
rhesus immunoglobulin Anti-D given to rhesus negative mothers before and after birth intramuscularly when the fetus is rhesus positive
also given after miscarriage or abortion
How does Anti-D work?
competitively binds and inactivates rhesus antigens, keeping them undetected by maternal antibodies
Thyroid function
hypothalamus secretes thyrotropin releasing hormone causing the anterior pituitary to release thyroid stimulating hormone
acts on the thyroid causing it to release T3 and T4
what are the thyroid hormones?
T3 - triiodothyronine
T4 - thyroxine
T3
responsible for almost all thyroid activity
half life = 1 day
T4
largely converted to T3 intracellularly
half life = 7 days
what produces T3/T4 ?
follicular cells secrete thyroid hormone
hypothyroidism
hashimoto’s thyroiditis
how does hypothyroidism present?
lethargy fatigue weight gain cold intolerance dry skin/ thinning hair
how to investigate hypothyroidism?
high levels of TSH
reduced levels of T3/T4
Anti-TPO antibodies
how to treat hypothyroidism?
levothyroxine
hyperthyroidism
grave’s disease
how does hyperthyroidism present?
weight loss heat intolerance tremor tachycardia diarrhoea goiter exopthalmus
what is the normal position of the uterus?
anteverted and anteflexed
what inhibits uterine contraction caused by oxytocin during pregnancy?
progesterone
what respiratory complication could occur in a premature newborn?
respiratory distress syndrome
how can respiratory distress syndrome be prevented?
corticosteroid treatment to the mother 24 hours pre-delivery
what produces surfactant?
type 2 alveolar cells
when does surfactant production take place?
starts at 24-28 weeks
increases significantly after 34 weeks
what stimulates surfactant production?
hormones:
- cortisol
- thyroxine
- prolactin
which hormone is most important in surfactant production?
cortisol
how does respiratory distress syndrome appear on an x-ray?
lung fields have a hazy appearance
how to treat respiratory distress syndrome post-birth
post-birth = oxygen, supportive continuous positive airway pressure (CPAP), administer surfactant
