Combination of repro physiology questions Flashcards
Progesterone related effects of pregnancy?
- lower BP
- constipation
- ureteral dilation
- bladder relaxation
- biliary stasis
- increased tidal volume
all due to smooth muscle relaxation
What substrate is responsible for lower blood pressure during pregnancy?
progesterone
- relaxes smooth muscle
What marks the change of primordial follicles to primary follicles?
Development of the zona pellucida
Granulosa cells have also started proliferating
What are pre-antral , secondary follicles most recognised by feature wise?
the development of the theca
Where is hCG mianly secreted from during pregnancy?
beta-hCG is produced by the placenta (syncytiotrophoblast cells)
hormone maintains the corpus luteum , which contains to secrete progesterone and oestrogen throughout pregnancy
can cause nausea and vomiting
Why does Cardiac output increase during pregnancy?
Increased Stroke Volume
- main contributer due to increased plasma volume
Up to what stage of oogenesis do cells develop to in utero?
Prophase 1
When a baby suckles on a mothers nipple it riggers the release of a compound into the blood that results in the contraction of cells in the mammary glands - resulting in milk being pushed out of the nipple
which compound is this?
Oxytocin
- stimulates milk contraction by triggering contraction of the myoeptihelial cells of alveoi of the mammory glands
what compound triggers milk ejection*?
oxytocin
(let down reflex) contraction of myoepithelial cells of the alveoli of the mammary glands
triggered by infant suckling
what compound triggers milk production*?
prolactin
Where is oxytocin released from?
posterior pituitary gland
which hormone causes uterine contraction
oxytocin
During pregnancy RBC and HB increase by 20% but why might someone still appear anaemic
50% increase in plasma - haemodilution results in apparent anaemia on FBC
why are WBC slightly increased during pregnancy
there is increased neutrophils due to physiological stress induced by pregnancy
why does breathing become deeper during pregnancy
effects of progesterone
tidal volume increases - intercostal muscles and diaphragm become more relaxed, allowing for increased inflation of the lungs when breathing
Sperm are haploid cells
a. true
b.false
a. true
contain a single set of chromosomes
what is responsible for hCG secretion?
syncytiotrophoblast cells of placenta
- hCG stimulates corpus luteum to secrete progesterone
Which type of receptor is bound to theca cells on follicles?
LH receptors
- LH causes theca cells to produce androstenedione which is converted to oestradiol by aromatase enzyme in granulosa cells
What do granulosa cells do?
convert androstenedione to oestradiol via aromatase enzyme
which part of the follicle produces hormones which prepare the womb for embryo implantation?
granulosa cells
- produce oestradiol during menstrual cycle under the influence of FSH
FSH stimulates the granulosa cells to change androgen sex hormones, released by theca cells, to estrogen sex hormones.
a. true
b. false
a. true
As your follicles grow, granulosa cells continue to produce more estrogen. This results in a surge in luteinizing hormone (LH) from your anterior pituitary.
a. true
b. false
a. true
granulosa cells produce estrogen under stimulation of FSH
primigravida meaning?
a women who is pregnant for the first time
when can Human chorionic gonadotropin hormone be detected?
8th day post fertilisation and peaks around 60 days
secreted by the chorion and maintains the corpus luteums secretion of oe
oxytocin stimulates uterine contractions
a. true
b. false
a. true
why is oxytocin often given to patients suffering from post-partum haemorrhage (PPH)?
the most common cause of post-partum haemorrhage is a failure of the uterus to contract
snythetic form - syntocinon (given /IV)
What happens GFR during pregnancy?
increases by 30-60%
function of leydig cells?
are found in the testes of men and produce testosterone in response to LH
function of sertoli cells?
protect and nourish developing sperm via spermatogenic cells
what does haemodilution mean? in pregnancy?
it occurs because blood plasma volume increases by 50%
but RBC only increases by 20%
therefore, the ratio of plasma to RBC is unmatched
Hb will be low
when is hCG secreted in pregnancy?
by synctiotrophoblasts after implantation
which begins days 6-7
completes around day 9-10 after fertilisation
when should women take a pregnancy test?
at least 7 days after sex (implantation) but ideally on the 1st day of missed period to maximise the change of an accurate result
In the first 4 weeks of pregnancy hCG doubles every 48-72 hours
a. true
b. false
a. true
early plateau or fall may indicate pregnancy problems (ectopic or miscarriage)
Why is trace glycosuria common in pregnancy?
due to increased GFR and reduction in tubular reabsorption of of filtered glucose
pulmonary ventilation and tidal volume increases during pregnancy
a. true
b. false
a. true
can cause acid-base disturbance : respiratory alkalosis
kidney’s can compensate by increasing excretion of HC03
Describe the fast block of sperm?
When the sperm first makes contact with the egg, it triggers a rapid influx of sodium ions into the oocyte. This causes a depolarisation of the oocyte membrane, which serves as a fast block to polyspermy by preventing the additional sperm from binding to and penetrating the egg.
This change is temporary and not sufficient alone to prevent polyspermy.
Describe the slow block against polyspermy?
The release of calcium ions within the egg following fertilisation.
the influx of calcium ions stimulates cortical granules in the eggs periphery to release their contents into the perivitelline space. This causes modifications within the zona pellucida (the outer layer surrounding the oocyte)
making it impenetrable to additional sperm
more permanent block
Stages of sperm fusing with the egg?
- sperm penetrates the corona radiata (outer layer) via membrane bound enzymes in the plasma head of the sperm.
- enzymes bind to ZP3 receptor on zona pellucida (next layer)
- sperm binding triggers acrosome reaction
- acrosomal hydrolytic enzymes digest the zona pellucida creating a pathway to the ovum plasma membrane
- the sperm enters the ovum cytoplasm
- the two cells of sperm and ovum fuse to produce diploid zygote
- sperm stimulates slow block - inactivates ZP3 receptors
after fertilisation , rapid mitotic cell divisions occur of the zygote to produce the embyro
a. true
b. false
a. true
Features of leydig cells in testes
- produce testosterone in response to LH
Sertoli cells are elongated in shape
a. true
b. false
a. true
Which cells in the testes secrete ABP - antigen binding protein?
the sertoli cells
support the developing sperm during spermatogenesis and form the blood - testes barrier
which cells in testes form the blood-testes barrier?
sertoli
why do creatinine and urea plasma levels fall during pregnancy?
increased renal perfusion
- allows greater clearing of substances from the circulation
- greater plasma volume diluting substances
