Physiology - Gender, Family & Culture Flashcards Preview

MBBS - Year 1 > Physiology - Gender, Family & Culture > Flashcards

Flashcards in Physiology - Gender, Family & Culture Deck (40)
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1
Q

What does the HPO axis control

A

Female reproduction

2
Q

What is the menstrual cycle

A

Ovarian and uterine cycle together

3
Q

The hormonal cycle tightly regulated to

A

Select ovarian follicle for ovulation

Prepare endometrium for implantation of fertilized follicle

4
Q

Duration of ovarian cycle

A

28 days

5
Q

Duration of follicular phase

A

Incl ovulation

1 -1 4

6
Q

Duration of luteal phase

A

Days 15-28

7
Q

What can cause changes in duration of ovarian cycle

A

The follicular phase, duration of the luteal phase remains unchanged

8
Q

The follicular phase

A

FSH increases and causes primordial follicles become primary follicles
1’ follicles –> 2’ follicles, the theca folliculi are formed
Each follicle contains an egg but only one fully matures

9
Q

What hormone is released during follicular phase

A

Oestrogen by cells of the thecca

10
Q

Where does ovulation occur

A

Alternate ovaries

11
Q

Ovulation phase

A

FSH and LH are high
The follicle ruptures and the 2’ oocyte is expelled into the abdominal cavity
The oocyte enters the fimbriated end of the fallopian tube

12
Q

Luteal phase

A

FSH and LH decrease and oestrogen and progesterone rise
The ruptured follicle caves in and fills with a blood clot
Corpus luteum forms

13
Q

Corpus luteum

A

Endocrine structure formed by granulosa and theca cells

14
Q

What does the corpus luteum secrete

A

Progesterone and oestrogen

15
Q

What is the corpus luteum essential in

A

Preparing for fertilization and for maintaining a pregnancy should it occur

16
Q

What happens if fertilisation does not occur during the luteal phase

A

The corpus luteum degenerates after 12-14 days due to decreasing levels of FSH and LH
The area of the corpus luteum becomes scar tissue (corpus albicans)

17
Q

What happens if fertilisation occurs during the luteal phase

A

The corpus luteum continues to function to maintain pregnancy until placental and fetal hormone production is sufficient

18
Q

When is the concentration of LH, FSH and oestrogen the highest

A

Just before ovulation

19
Q

When is the concentration of progesterone the highest

A

Days 20-26

20
Q

Hormones secreted by hypothalamus

A

GnRH

21
Q

Hormones secreted by pituitary gland

A

FSH and LH

22
Q

Hormones secreted by ovary

A

Oestrogen and progesterone

23
Q

What is the uterine cycle

A

Changes occurring in the uterus as the endometrium responds to ovarian hormones
Corresponds to the ovarian cycle

24
Q

What does the uterine cycle prepare the endometrium for

A

Possible implantation by the fertilized embryo

25
Q

Phases of uterine cycle

A

Proliferative
Secretory
Menstrual

26
Q

Proliferative phase

A

Corresponds to the follicular phase of the ovarian cycle
Starts ~day 5 when bleeding ceases
The release of oestrogen results in cell proliferation & regeneration of the stratum functionalis

27
Q

Cervical mucus in proliferative phase

A

Changes from a thick plug, blocking the cervix to profuse amounts of thick slippery mucus that can be penetrated by spermatozoa

28
Q

Secretory phase

A

Corresponds with the luteal phase of the ovarian cycle
14 days in duration
The endometrium prepared by oestrogen is now influenced by progesterone

29
Q

Cervical mucus in secretory phase

A

Changes to a thick plug, blocking the cervical canal and protecting the embryo

30
Q

Menstrual phase of uterine cycle

A

The spiral arteries in the endometrium dilate and bleed into the necrotic stratum functionalis and this lasts 3- 6 days

31
Q

What causes the uterus to contract during menstruation

A

Prostaglandins

32
Q

Body temperature variation during menstruation

A

Fall corresponding with the LH surge ~24hrs priors to ovulation
Progesterone secreted by the corpus luteum results in a rise in metabolic rate & temp by 0.5 degrees
This rise persists until menstruation

33
Q

Altered pathology of HPO axis and menstruation

A
Abnormal uterine bleeding 
Endometriosis 
Infertility 
Endocrinopathies 
Genetic causes 
Iatrogenic 
Age and weight impact
34
Q

Endocrinopathies causing altered pathology

A

Hypothyroidism

35
Q

Genetic causes of altered pathology

A

Turner syndrome (complete or partial X chromosome deletion)

36
Q

Iatrogenic causes of altered pathology

A

Impact of chemo

37
Q

How does moderate oestrogen levels impact the menstrual cycle

A

Exert negative feedback on the HPO axis

38
Q

How does high oestrogen levels (in the absence of progesterone) impact the menstrual cycle

A

+vely feedback on HPO axis

39
Q

How does oestrogen levels in the presence of progesterone impact the menstrual cycle

A

-vely feedback on HPO axis

40
Q

Inhibin

A

Produced by granulosa cells

Selectively inhibits FSH at the anterior pituitary

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