Reproductive System Flashcards
What does gonadotropin-releasing hormone stimulate the anterior pituitary to produce?
FSH and LH
What cells around the follicles in the ovary produce oestrogen?
Theca and granulosa cells
What effect does oestrogen have on hypothalamus and anterior pituitary?
Supress the release of GnRH from hypothalamus and LH+FSH from anterior pituitary
What is the most prevalent and active version of oestrogen?
17-beta oestradiol
What changes does the action of oestrogen on its receptors stimulate in the body?
Breast tissue development, development of female sex organs in puberty, blood vessel development in uterus, development of endometrium
What are oestrogen and progesterone?
Steroid sex hormones
where is progesterone produced normally and during pregancy?
Corpus luteum after ovulation normally
In pregnancy progesterone is produced from placenta after 10 weeks gestation
What does progesterone cause?
Thickening of cervical mucus
Thickens and maintains the endometrium
Increase body temperature
Why is it that overweight girls tend to undergo puberty earlier?
Aromatase enzyme is found in adipose tissue. The more adipose tissue the more aromatase which is important in creation of oestrogen
How is GnRH produced in puberty?
Initially during sleep, then throughout the day in later stages
What are the four stages of development a follicle undergoes in the ovary?
Primordial follicles
Primary follicles
Secondary follicles
Antral follicles
Which stages of development of the follicles in the ovary occurs independently to the menstrual cycle?
Primordial follicles developing into primary and secondary follicles
After what stage do follicles develop receptor for FSH and require FSH stimulation for further growth?
Secondary follicles develop FSH receptors
What is a dominant follicle?
A follicle that develops further than the rest during a menstrual cycle
A spike in what hormone causes ovulation?
LH
What maintains corpus luteum if ovum becomes fertilised?
HCG produced from the syncytiotrophoblast of embryo maintains corpus luteum
What happens with corpus luteum if egg is not fertilised and how does this affect hormone levels?
Initially corpus luteum produces progesterone and smaller amounts of oestrogen, it degenerates if ovum isnt fertilised and stops producing hormones so there is a drop in progesterone and oestrogen
What does a drop in the oestrogen and progesterone levels cause?
Causes the endometrium to break down and menstruation to occur
Drop in negative feedback to hypothalamus and pituitary also allows LH and FSH to rise
What are the 3 layers of a primary follicle?
Primary oocyte in centre
Zona pellucida
Granulosa cells
What are the two layers of the theca folliculi?
Inner layer- secretes androgen hormones
External layer- smooth muscle and collagen
What is the change seen from development from secondary follicle to antral?
Development of an antrum which is a single fluid filled areas within granulosa cells
What happens in a follicle at ovulation?
LHsurge causes contraction of smooth muscle in external thecal layer bursting follicle. Digestive enzymes from follicle create a hole in ovary wall for ovum to pass through
How doe the granulosa and thecal cells change in corpus luteum?
They become luteal cells producing steroid hormones- particularly progesterone
What is the decidua?
Cells of the stroma (supportive outer tissue of endometrium) converted into a tissue specialised to provide nutrients to the trophoblast
What tissues are derides from the ectoderm?
CNS, skin, hair, teeth, nails
What tissues are derived from the mesoderm?
Bone, Muscle, Heart, connective tissue, blood, kidneys
What tissues are derived from the endoderm?
GI tract, lungs, liver, pancreas, thyroid, reproductive system
At what week gestation does the fetal heart form and start to beat?
Six weeks
What are spiral arteries in the uterus?
Artery branches from the myometrium into the endometrium which are thicker walled and coiled
What are chorionic villi?
Finger like projections of the syncytiotrophoblast which grow in the endometrium when the blastocyst implants on the endometrium. They contain fetal blood veesels
What is the chorion frondosum?
Vascular area of chronic villi near connecting stalk which contain mesoderm. This proliferates and becomes the placenta
what does the connecting stalk become?
The umbilical cord
When is placenta development complete?
Usually by ten weeks gestation
Which direction do the umbilical arteries and vein take blood to and from the baby?
The 2 umbilical arteries carry deoxygenated blood from the baby to the placenta
The umbilical vein carries oxygenated blood from the placenta to the baby
How is oxygen able to be taken up by fetal blood from placenta?
Fetal haemoglobin has a higher affinity for oxygen
What are the five main function of the placenta?
Respiration, nutrition, excretion, endocrine, immunity
What does oestrogen help with in pregnancy?
Helps soften tissues allowing muscles and ligaments of the uterus and pelvis to expand and cervix to soften ready for birth
Enlarges breasts and nipples for birth
what does progesterone help with in pregnancy? What are some side effects?
Maintains endometrial blood supply, relaxes muscles so uterus doesn’t contract
Relaxing of other muscles like lower oesophageal sphincter (heart burn), bowel (constipation) and blood vessels (flushing, hypotension, headaches)
What physiological change in pregnancy may lead to improvement in autoimmune conditions and increased susceptibility to diabetes and infections?
Increase in ACTH production causing increased steroid hormones like cortisol
Why are skin changes like linea nigra and melisma more common in pregnancy?
Increased melanocyte stimulating hormone production from anterior pituitary
How do thyroid test levels changes in pregancy?
TSH level remains the same, T3 and T4 increase
How do HCG levels change in early pregnancy?
The levels rise doubling every 48 hours, plateauing around 8-12 weeks then gradually fall
What changes are seen in the cervix and vagina with increased oestrogen?
Increased cervical and vaginal discharge, cervical ectropion more likely and hypertrophy of vaginal muscles
What effect do prostaglandins have on the cervix during childbirth?
They break down the collagen in the cervix allowing it to dilate and a face during childbirth
What cardiovascular changes are seen in pregnancy?
Increased blood volume, plasma volume, cardiac output, stroke volume and heart rate. Reduced peripheral resistance with decreased blood pressure
Why are varicose veins seen in pregnancy?
Peripheral vasodilation and obstruction of inferior vena cava by uterus
What are some respiratory changes seen in pregnancy?
Increased tidal volume and respiratory rate in later pregnancy
What renal changes are seen in pregnancy?
Increased GFR from increased blood flow to kidneys
increased aldosterone so more water and salt reabsorption
increased protein excretion
dilatation of ureters and collecting system
What are some haematological changes seen in pregnancy?
Increased RBC production (not as much as plasma volume so haematocrit falls resulting in anaemia)
Clotting factors increase- hypercoagulable state
Decreased platelets
Increased WBCs
What are some biochemistry changes seen in pregnancy?
Increased ALP (due to secretion from placenta)
Reduced albumin (increased loss from kidneys)
Is postpartum hair loss normal?
Yes and usually improves within 6 months
What is the first stage of labour?
From the onset of true contractions until 10cm cervical dilatation
what is the second stage of labour?
From 10cm dilatation to delivery of baby
What is the third stage of labour?
Delivery of baby to delivery of placenta
Pessaries containing what can be used to induce labour?
Prostaglandin E2 (dinoprostone)
What are Brixton hicks contractions?
Occasional and irregular contractions of uterus, which can cause temporary and irregular cramping or tightening feelings. They dont indicate onset of labour.
In the first stage of labour, what is meant by ‘show’?
The mucus plug in the cervix preventing bacteria entering uteru falls out breathing space for baby to come out
What are the three phases seen in the first stage of labour?
Latent phase: 0-3cm at 0.5cm an hour, irregular contractions
Active phase: 3-7cm at 1cm an hour, regular contractions
Transition phase: 7-10cm at 1cm an hour, strong and regular contractions
What are the 3 Ps which determine the success of the second stage pf labour?
Power, passenger and passage
In labour what are the 4 descriptive qualities of the foetus?
Size
Attitude (posture e.g how back is rounded/limb or heads flexed),
Lie (position of foetus in relation to mum)
Presentation (part of foetus closest to cervix)
What are the different possible lies of a foetus?
Longitudinal- foetus is straight up and down
Transverse lie- foetus straight side to side
Oblique- foetus at an angle
What are the different presentations of a foetus?
Cephalic
Shoulder
Breech (legs first)
What are the different types of breech presentation?
Complete breech- hips and knees flexed (cannonball into pool)
Franck breech- hips flexed and knees extended, bottom first
Footling breech- with a foot hanging through the cervix
What are the seven cardinal movements of labour?
Engagement, descent, flexion, internal rotation, extension, restitution and external rotation, expulsion
When is active management of the third stage of labour considered?
Haemorrhage or more than 60 minute delay in delivery of placenta
What is active management of the third stage of labour?
Intramuscular oxytocin
