Repro Anatomy/ Physiology Flashcards
Label the following:


Label the following:


Label the following:


Label the following:


What hormones are involved in the hypothalamic-pituitary-gonadal axis?
Hypothalamus = GnRH
Anterior pituitaty = LH and FSH (stimulate development of follicles)
What part of the follicles secrete oestrogen?
Theca granulosa cells
What effect does oestrogen have on the hypothalamus and anterior pituitary?
Negative feedback effect
What kind of hormone is oestrogen?
Steroid sex hormone
What is the most active version of oestrogen?
17-beta oestradiol
Where does oestrogen work?
On tissues with oestrogen receptors to promote female secondary sexual characteristics
What changes does oestrogen stimulate?
- Breast tissue development
- Development of female sex organs at puberty
- Blood vessel development in the uterus
- Development of the endometrium
What kind of hormone is progesterone?
Steroid sex hormone
Where and when is progesterone formed?
Corpus luteum after ovulation
After pregnancy where is progesterone mainly formed?
Placenta from 10 weeks gestation onwards
What does progesterone do?
Acts on tissues which have previously been stimulated by oestrogen
What does progesterone do?
Thickens and maintains the endometrium
Thickens the cervical mucus
Increases the body temperature
What age does puberty begin in girls and boys respectively?
Girls = 8-14
Boys = 9-15
What enzyme is found in adipose tissue which is important in the creation of oestrogen?
Aromatase
When may puberty be delayed?
- Low birth weight
- Chronic disease
- Eating disorders
- Athletes
What is the order of puberty in girls?
- Breast buds
- Pubic hair
- Menarche (first episode of mensturation)
What scale can be used to stage pubertal development?
Tanner scale
What hormone initially rises during puberty?
Growth hormone
In puberty what is released after GH and what is its function?
GnRH stimulates the release of FSH and LH
What does FSH and LH stimuate in the woman?
Production of oestrogen and progesterone
How does FSH and LH change just before menarche?
FSH levels plateau a year before
LH continues to rise and spike just before menarche
What suppresses GH in women?
Oestrogen
What are the two phases to the menstural cycle?
Follicular phase (start of mensturation to moment of ovulation)
Luteal phase (final 14 days of cycle)
Which cells have the potential to develop into eggs?
Oocytes
Which cells surround the oocytes?
Granulosa cells (forming follicles)
What are the 4 key stages of development of the follicles?
Primordial follicles
Primary follicles
Secondary follicles
Antral follicles (aka Graafian follicles)
When do primordial follicles mature into primary and secondary follicles?
Always occuring, independent of the menstural cycle
At what point do the follicles develop the receptors for FSH?
Secondary follicle stage (further development requires FSH)
At the start of the menstural cycle, what stimulates further development of the secondary follicles?
FSH
What secretes oestradiol in the woman?
Granulosa cells
What effect does this oestradiol have on the pituitary gland?
Negative feedback (reducing LH and FSH)
What effect does the rising oestrogen have on the cervical mucus?
Makes it more permeable allowing sperm to penetrate the cervix
What hormone spikes just before ovulation, causing the dominant follicle to release the ovum (an unfertilised egg)
Luteinising hormone
What happens to the follicle that releases the ovum?
Collapses and becomes the corpus luteum
What hormone does the corpus luteum secrete?
Progesterone
(and a little oestrogen)
What effect does the progesterone from the corpus luteum have?
Maintains endometrial lining
Causes cervical mucus to become thick and no longer penetrable
Where does human chorionic gonadotrophin (HCG) come from?
Syncytiotrophoblast of the embryo
What is the purpose of HCG?
Maintains the corpus luteum
What causes mensturation?
No production of hCG = corpus luteum degenerates = production of oestrogen and progesterone stops = endometrium breaks down and mensturation occurs
During mensturation where does prostalandins come from?
Stromal cells of the endometrium
What is the purpose of prostaglandins?
Encourages the endometrium to break down and uterus contracts
What day of the menstural cycle does mensturation occur on?
Day 1
Why does LH and FSH begin to rise at the beginning of the menstural cycle?
Due to negative feedback from the corpus luteum stopping (so progesterone and oestrogen decreases)
What layers of the endometrium are lost during mensturation?
Superficial and middle
What layer of the endometrium is kept during mensturation?
Basal layer
What type of cells are oocytes?
Germ cells - undergo meiosis to become mature ovum (ready for fertilisation)
How many chromosomes do ovum contain?
46
What are the three layers to the primary follicle?
- Primary oocyte in centre
- Zona pellucida
- Cuboidal shaped granulosa cells
Where does the zona pellucida come from in the primary follicles?
Secreted by the granulosa cells (they also secrete oestrogen)
What layer develops on top of the granulosa layer?
Theca folliculi
What are the two layers of the theca folliculi?
Theca interna and theca externa
What does the theca interna secrete?
Androgen hormones
What is the theca externa made up of?
Connective tissue containing smooth muscle and collagen
What is the difference between primary and secondary follicles?
Secondary are larger with small fluid-filled gaps between granulosa cells
Receptors for FSH
What is required for the further development of the secondary follicle?
Stimulation from FSH
What develops in the secondary follicle and what is this called?
Single large fluid-filled area in the granulosa called the antrum
Once the antrum is formed, what surrounds the oocyte now?
Corona radiata - made of granulosa cells (surrounding the zona pellucida and oocyte)
What causes the follicle to burst during ovulation?
LH surge (causes the smooth muscle of the theca externa to burst)
What sweeps along the oocyte?
Fimbriae of the fallopian tubes
Once ovulation occurs what happens to the cells of the follicle?
Become luteal cells
At what point do the 46 chromosomes split to become 23 in the oocyte?
Just before ovulation the primary oocyte undergoes meiosis creating a haploid cell (the other 23 chromosomes float off to the side and become a polar body) it is then a secondary oocyte
When the sperm enters the egg what happen to the chromosomes of the egg?
They multiply into two sets and only one set combines with the 23 chromosomes from the sperm to form a diploid set of 46 chromosomes
What happens to the other set of 23 chromosomes?
Float off to the side to create the second polar body
What is the fertilised egg called?
Zygote
After rapid divison what is the zygote then called?
Morula
How does the morula change?
A fluid filled cavity gathers within the group of cells and it becomes a blastocyst
What are the components of the blastocyst?
- Embryoblast: main group of cells in the middle
- Blastocele: fluid filled cavity
- Trophoblast: outer layer of cells
(gradually losing the corona radiata and zona pellucida)

When does the blastocyst arrive in the uterus?
8-10 days after ovulation
Which cells of the blastocyst implant on the endometrium?
Cells of the trophoblast undergo adhesion to the stroma (supportive outer tissue) of the endometrium
What is the outer layer of the trophoblast called?
Syncytiotrophoblast (this layer forms projections into the stroma)
What do the cells of the stroma (supportive outer tissue of the endometrium) convert into?
Decidua
What is the role of the decidua?
Provides nutrients to the trophoblast
After implantation of the blastocyst, what starts producing HCG?
Syncytiotrophoblast
What is the purpose of HCG?
Maintains the corpus luteum in the ovary, allowing it to continue producing progesterone and oestrogen
After implantation when does the blastocyst start to differentiate?
A week after fertilisation
What does the embryoblast differentiate into?
Yolk sac
Amniotic cavity
Divided by the embryonic disc
What does the embryonic disc divide into?
Fetal pole into the fetus
What surrounds the yolk sac and amniotic cavity?
The chorion (two layer: cytotrophoblast, syncytiotrophoblast)
Label the following:


What does the connecting stalk eventually become?
Umbilical cord
When does the embryonic disc become the fetal pole?
5 weeks gestation
What are the three laters of the fetal pole?
Ectoderm (outer layer)
Mesoderm (middle layer)
Endoderm (inner layer)
Name some derivatives of the three germ cell layers?

At what point gestation have all the major organs developed?
8 weeks gestation, from this point the fetus matures and grows until birth
What are the spiral arteries?
Artery branches in the endometrium from the myometrium
What is the chorionic villi?
Finger-like projections from the syncytiotrophoblast into the endometrium containing foetal blood vessels
Where is the chorionic villi most vascular?
Chorion Frondosum: nearest the connecting stalk - these contain mesoderm
What cells become the placenta?
Cells of the chorion frondosum
When is placental development complete by?
10 weeks gestation
What signal reduces vascular resistance of the spiral arteries?
Signals from the trophoblast invasion of the endometrium make the spiral arteries more fragile
When the spiral arteries break down, what is left?
Lacunae = pools of blood
What does the maternal blood flow through?
From uterine arteries into lacunae and back out through uterine veins
What point in gestation does lacunae form?
20 weeks gestation
What separates the lacunae from the chorionic villi?
Placental membrane
What can result if the process forming lacunae is inadequate?
Pre-eclampsia
What is pre-eclampsia caused by?
High vascular resistance in the spiral arteries
What are the functions of the placenta?
Respiration
Nutrition
Excretion
Endocrine
Immunity
Where does the foetus’ oxygen come from?
Placenta
How does foetal Hb differ from adult Hb?
Foetal Hb has a higher affinity for oxygen
What is exchanged in the placenta which helps with acid-base balance?
Carbon dioxide
Hydrogen ions
Bicarbonate
Lactic acid
What is the main form of nutrition for the foetus?
Glucose used for energy and growth
What substances can a mother consume which will harm a foetus?
Medications
Alcohol
Caffeine
Cigarette smoke
What are the waste products from a foetus?
Urea
Creatinine
Where does hCG come from and what is its purpose?
Syncytiotrophoblast (increasing in early pregnancy and then plateauing)
What is the purpose of hCG?
Maintains the corpus luteum until the placenta can take over the production of oestrogen and progesterone
What is a side effect of hCG production?
Nausea and vomiting in early pregnancy
When are there higher levels of hCG?
Twins
Molar pregnancies
The placenta produces oestrogen, what is it’s purpose?
- Allows expansion of the muscles and ligaments of the uterus and pelvis
- Softens the cervix, ready for birth
- Enlarges the breast and nipples for breastfeeding
The placenta produces progesterone, what is it’s purpose?
Maintain the pregnancy
Relaxes the uterine muscles
Maintains the endometrium
Progesterone can relax other muscles, what are the side effects of this?
- GORD due to relaxation of the LOS
- Constipation due to relaxation of the bowel
- Hypotension due to relaxation of the blood vessels (causing hypotension, headaches and skin flushing)
How much does body tempterature increase during pregnancy?
0.5 to 1 degree celsius
What carries oxygenated blood to the fetus?
Umbilical vein
What is produced in excess in pregnancy?
ACTH
Prolactin
Melanocyte stimulating hormone
What does the rise in ACTH cause?
Rise in steroid hormones: cortisol and aldosterone
What does the higher steroid levels cause in pregnancy?
- Improvement in autoimmune conditions
- Susceptibility to diabetes and infections
What does the increase in prolactin during pregnancy cause?
Suppression of FSH and LH
What does the increase in melanocyte stimulating hormone cause in pregnancy?
Increased pigmentation of the skin during pregnancy
What does the increase in skin pigmentation during pregnancy cause?
Linea nigra
Melasma
How do thyroid hormones change during pregnancy?
TSH remains normal
T3 and T4 levels rise
When do hCG levels fall during pregnancy?
Around 8-12 weeks
What is the role of progesterone in pregnancy?
Maintains the pregnancy
Prevents contractions
Supress the mother’s immune system
How does the uterus change in size during pregnancy?
Increases from 100g to 1.1kg
How does the myometrium change during pregnancy?
Hypertrophy of the myometrium and the blood vessels
How may the cervix change during pregnancy?
Cervical ectropion
Increased cervical discharge
What causes increased vaginal discharge in pregnancy?
Increase in oestrogen (also causes hypertrophy of the vaginal muscles as it increases throughout pregnancy)
How does the cervix change before delivery?
What are the cardiovascular changes in pregnancy?
Increased: blood volume, plasma volume, cardiac output
Decreased: preipheral vascular resistance, blood pressure
Varicos veins (peripheral vasodilation and obstruction of the IVC), peripheral vasodilation causing flushing and hot sweats
What are the renal changes in pregnancy?
Increased GFR
Increased aldosterone = increased salt and water reabsorption
Increased protein excretion from the kidneys
Dilation of the ureters leading to physiological hydronephrosis
What are the haematological changes in pregnancy?
Increased RBCs
Increased plasma volume
What nutritional demands do the increase in RBCs cause?
Higher iron, folate and B12
Why is there a lower concentration of RBCs in pregnancy?
As plasma volume increases more than RBC volume
Why does anaemia occur in pregnancy?
High plasma volume means the haemoglobin concentration and red cell concentration fall in pregnancy
What clotting factors increase in pregnancy?
Fibrinogen
Factor VII, VIII and X
What is a result of the increase in clotting factors in pregnancy?
Increased risk of VTE
What are the other blood changes during pregnancy?
Increased white blood cells, ALP (from the placenta), ESR, D-dimer,
Decreased platelet count and reduced albumin
What are the skin changes in pregnancy?
- Pigmentation (due to increase in MSH = linea nigra and melasma)
- Striae gravidarum (stretch marks on the abdomen)
- Pruritus (normal / obstetric cholestatsis)
- Spider naevi
- Palmar erythma
What are the hair changes in preganancy?
Postpartum hair loss (normal and usually improves in 6 months)
When does labour usually occur?
Between 37 and 42 weeks gestation
What are the 3 stages of labour?
First stage = onset of labour to 10cm cervical dilation
Second stage = from 10cm dilatation to delivery of baby
Third stage = from delivery of the baby to delivery of the placenta
What role do prostaglandins have in pregnancy?
- Stimulate contraction of the uterine muscles
- Ripening the cervix before delivery
What is in the pessaries which induce labour?
Prostaglandin E2 (dinoprostone)
What are Braxton-Hicks contractions?
Occasional and irregular contractions of uterus - don’t progress and become regular - not true contractions (staying hydrated and relaxing can help reduce)
What are the components of the first stage of labour?
Cervical dilation (opening up)
Effacement (getting thinner)
What is the purpose of “the show” - the mucus plug in the cervix?
- Prevents bacteria from entering / falling out
What are the 3 phases of the first stage of pregnancy?
Latent phase = 0 to 3cm dilation of cervix, irregular contractions (0.5cm per hour)
Active phase = 3 to 7cm dilation, regular contractions (1cm per hour)
Transition phase = 7 to 10cm dilation, strong and regular contractions (1cm per hour)
What are the 3 Ps of the second stage of labour?
Power
Passenger
Passage
What does power depend on?
Strength of uterine contractions
How can the passenger be described?
Size (of head)
Attitude (posture of the fetus - how back is rounded /head and limbs are flexed)
Lie (longitudinal/transverse/oblique)
Presentation (part of fetus closest to cervix = cephalic / shoulder / breech)
What are the 3 different types of breech
Complete (hips and knees flexed)
Frank (bottom first - hips flexed and knees extended)
Footling (foot hanging through cervix)
What does Passage stand for?
Size and shape of the passageway, mainly pelvis
What are the seven cardinal movements of labour?
Engagement
Descent
Flexion
Internal rotation
Extension
Restitution and external rotation
Expulsion
How is the babies head position described during delivery?
In relation to the mother’s ischial spines during the descent phase:
-5cm
0
5cm
What are the different management options for the 3rd stage of labour?
Physiological management (placenta is delivered by maternal effort only)
Active management (midwife/dr helps with delivery of the placenta, shortens phase and reduces risk of bleeding) - haemorrhage or 60 min delay should prompt active management - associated with N&V
Intramuscular oxytocin can be given to help the uterus contract and expel the placenta (careful traction is applied to the umbilical cord to guide the placenta out of the uterus)
Describe the blood supply to the uterus
Uterine artery
- Branches from internal iliac
- Runs behind the peritoneum to enter the lateral border of the uterus, through 2 layers of the broad ligament
- Anastomoses w/ the ovarian & vaginal arteries
Describe the blood supply to the ovaries?
- Ovarian arteries: branches of abdominal aorta from below the renal arteries
- The R ovary drains directly into IVC
- L ovary drains into L renal vein
Describe the relationship of the bladder and the uterus
The bladder lies anterior to the uterus
Describe the lymphatic drainage of the female pelvic organs (vulva, lower vagina, cervix, endometrium, ovaries)
Why is it important to have knowledge of lymphatic drainage?
Lymphatic drainage of the pelvic organs
- Vulva and lower vagina→ inguinofemoral → external iliac nodes.
- Cervix→ cardinal ligaments → hypogastric, obturator, internal iliac → common iliac, and para-aortic nodes.
- Endometrium→ broad ligament → iliac and para-aortic nodes.
- Ovaries→ infundibulopelvic ligament → para-aortic nodes.
Knowledge of lymphatic drainage is important when considering metastatic spread from genital tract cancer.