menstrual cycle

Question 1

female reproductive cycle

what 2 things characterise menarche in the female reproductive lifecycle and what is the average age it occurs?

Think uterine bleed and what it is in response to and think HPO axis

Answer 1

• first ovarian-controlled uterine bleed in response to increased levels of oestrogen (Periods)
• also represents maturation of HPO axis
• average age this occurs is 13 years old

Question 2

female reproductive lifecycle

what is the mean age of menopause?

Answer 2

51.5 years

Question 3

female reproductive lifecycle

what are 5 features of the ovarian cycle?

Think ovulations, ovum and endocrine regulation, primordial follicle, the phases of the ovarian cycle and folliculogenesis

Answer 3

1. intervals between successive ovulations
2. displays ovum maturation and release under endocrine regulation
3. progression of a primordial follicle to the corpus luteum
4. comprises of follicular phase (1-14 days) all the way to the luteal phase (12-28 days)
5. shows folliculogenesis

Question 4

reproductive cycles

what 5 things happen/is shown in the uterine cycle?

think hormones on uterus, what the endometrium is doing in the cycle, think phases of uterine cycle, think blood vessels, think proliferation of blood vessels

Answer 4

• effects of ovarian hormones on uterus
• endometrium is central tissue degenerating and regenerating
• proliferative phase –> secretory phase
• vascular function
• angiogenesis

Question 5

reproductive hormones in the female reproductive tract

name the 6 hormones involved in the female reproductive tract

Answer 5

• oestradiol-17b
• progesterone
• FSH
• LH
• Inhibins
• Anti-mullerian hormone (AMH)

Question 6

actions of sex steroids

what 6 things oestrogens do

think reproductive, muscloskeletal vascular and CNS, think GnRH secretion, think endometrium regrowth, think endometrium for progesterone, secondary female sex characteristics, think breast tissue

Answer 6

• effects: on reproductive,muscloskeletal,vascular and central nervous system
• regulates GnRH secretion
• stimulates proliferation of endometrium
• prepare endometrium for proliferation of endometrium
• stimulates secondary characteristics of the female
• stimulate ductal growth of breast tissue

Question 7

actions of the sex steroids

what are 6 things that progesterone does in the body

think GnRH, think endometrium and implantation and deciduslisation, think uterus, think breast tissue, think oestrogen

Answer 7

• regulates GnRH secretion
• prepare endometrium for implantation
• stimulate decidualisation of endometrium
• maintains uterus during pregnancy
• stimulates growth (alveolar) of breast tissue
• synergistic and opposing effects to oestrogen

Question 8

idealised menstrual cycle

what is the order of the idealised menstrual cycle and what days are the bleeding and ovulation phases

Answer 8

1. Bleeding (Day 1-7)
2. Proliferative (follicular)
3. ovulation (Day 13-15)
4. secretory (luteal)
5. implantation (if sperm reaches egg) –> pregnancy

Question 9

phases of the menstrual cycle

what hormone dominates the proliferative phase and what hormone dominates the secretory phase of menstrual cycle

Answer 9

• proliferative: oestrogen
• secretory: progesterone

Question 10

phases of the menstrual cycle

which phase of the menstrual cycle is variable and why does the secretory phase last 14 days

Answer 10

the proliferative phase

• secretory phase lasts 14 days because corpus luteum only survives for 14 days

Question 11

hormone levels in menstrual cycle

outline hormone levels of Oestrogen, Progesterone, LH and FSH from Day 1 of menstrual cycle

For stage 1, think what happens to FSH and LH levels and why.

For stage 2, think what FSH and LH do and what this does to levels of another hormone.

For stage 3, think what oestrogen does, the day it peaks and what it causes to the levels of LH and why it is effected

For stage 4, think about what now happens to LH and FSH levels and what happens to progesterone levels and why

For stage 5, think what happens to progesterone and oestrogen levels if implantation does not occur

Answer 11

1. FSH and LH slightly rise because of lack of oestrogen and progesterone so no negative feedback
2. FSH and LH rising stimulate follicles in ovaries to produce Oestrogen, causing an oestrogen spike.
3. Oestrogen promotes endometrial proliferation, with peak at day 12-14, and also causes LH peak due to positive feedback as LH needs to be maximum prior to ovulation.
4. LH and FSH levels then fall rapidly, and there is a progesterone peak to allow thickening of endometrium to prepare the endometrium for implantation.
5. if implantation does not occur, progesterone and oestrogen levels fall.

Question 12

hormone levels in menstrual cycle

what is the function of inhibins in the menstrual cycle

Answer 12

to inhibit the growth of other follicles

Question 13

endometrial structure and histology

what type of tissue is the endometrium and what has it got in it

Answer 13

glandular tissue with extensive stroma

Question 14

endometrial stucture

what is the window of implantation

Think blastocyst

Answer 14

• time period when endometrium is optimally receptive to blastocyst

Question 15

pinopodes

what are the markers of endometrial receptivity called and what do they do

Answer 15

• pinopodes
• attract blastocyst to endometrium

Question 16

endometrial histology

in proliferative phase and secretory, what shape are the glands in the endometrium?

Answer 16

Proliferative:
- round and regular

Secretory:
- tortuous twisted glands

Question 17

endometrial vascular supply

what artery supplies the endometrium

Answer 17

• the uterine artery

Question 18

endometrial vascular supply

what are the 2 layers of the endometrium and which layer is shed

Answer 18

• the functionalis layer (this layer is shed)
• the basalis layer

Question 19

vascular aspects

outline how endometrial hypoxia occurs subsequently leading to tissue degeneration when the endometrium is shedding

Answer 19

spiral artery coiling causes resistance to blood flow thus leading to endometrial hypoxia causing the functionalis layer to die and shed.

Question 20

vascular aspects

outline how progesterone withdrawal causes vasoconstriction of blood vessels in the endometrium contributing to shedding of the functionalis layer

think progesterone on COX-2,

Answer 20

1. progesterone withdrawal increases expression of COX-2
2. this progesterone withdrawal also increases:
   - prostaglandin (PGF2a) production by endometrial stromal cells
   - prostaglandin receptor density on blood vessels
3. these increases lead to vasoconstriction

Question 21

vascular aspects

why is the menstrual blood low viscosity?

Answer 21

because it needs to leave the uterus as easily as possible

Question 22

Days 1-7 of menstrual (follicular/proliferative phase)

when in the menstrual cycle is a dominant follicle selected and when will it ovulate?

Answer 22

• selected in follicular/proliferative phase
• ovulates in the next menstrual cycle

Question 23

Days 14-28 (luteal/secretory phase)

what 3 things does progesterone do in luteal/secretory phase of reproduction

Answer 23

• causes differentiation of endometrial glands to prepare for implantation
• maintains endometrium
• induces decidualisation

Question 24

decidualisation

what is decidualisation

Answer 24

• transformation of endometrial stromal cells to decidual cells by cAMP and progesterone

Question 25

# decidualisation what type of cells are decidual cells and what 3 things do they do ## Footnote think secretion, glycogen and lipids for first part for second part, think nutrition, prolactin and uNK and immune tolerance

Answer 25

- secretory, glycogen rich, lipid rich cells - provide early nutrition for the embryo - secrete prolactin - plays role in immune tolerance as rich in uNK

Question 26

# cervical mucus describe the texture of cervical mucus in proliferative phase and secretory phase ## Footnote for first part think about 3 textures that would aid sperm transport for second part think about the mucus trying to stop anything getting past

Answer 26

Proliferative phase: - thin, watery and stretchy to aid sperm transport secretory phase: - thick, impenetrable mucus

Question 27

# cervical mucus what is spinnbarkeit

Answer 27

stretch in fluids (eg cervical mucus)

Question 28

# menstrual disorders what is the difference between primary and secondary dysmenorrhoea?

Answer 28

Primary: - absence of underlying pelvic pathology secondary: - underlying pelvic pathology

Question 29

# endometriosis what is endometriosis

Answer 29

- condition where endometrial tissue is found outside uterus

Question 30

# endometriosis what can cause endometriosis? ## Footnote think menstruation, inflammation, apoptosis and angiogenesis

Answer 30

- retrograde menstruation - inflammation due to cytokines - reduced apoptosis of endometrial cells - angiogenesis so endometrial cells dont die

Question 31

# Leiomyomas (fibriods) what is leimyomas

Answer 31

tumours in the uterus (usually benign)

Question 32

# leiomyomas what are leiomyomas dependent on and when do they regress

Answer 32

- dependent on hormones - regress after menopause

Question 33

# leiomyomas (fibroids) what are 4 symptoms of leiomyomas and what 3 ways can it affect pregnancy/cause infertility? ## Footnote for first part, think pain of an area that holds the uterus, bloating, not being able to do a number 2 and the amount of times one urinates for second part, think blastocyst attachment, fallopian tubes and labour issues

Answer 33

Symptoms: - pelvic/back pain/pressure - feeling bloated - constipation - increases urinary frequency Leiomyomas can: - prevent the blastocyst attachment to the uterine wall - block fallopian tubes - lead to difficulties in labour leading to caesarean sections

Question 34

# HPO (hypothalamic-pituitary ovarian) dysfunction what 5 things can cause disordered GnRH release in the HPO axis ## Footnote think being worked up, intense workouts, weight, eating too much or too little, being affected by time zones from a plane

Answer 34

- stress - strenuous exercise - excessive weigth gain/loss - eating disorders - jet lag