Physiology

Question 1

Where is sperm produced?

Answer 1

Produced by Sertoli cells

In the seminiferous tubules of the testes

Question 2

Describe the hypothalamic-pituitary-gonadal axis?

Answer 2

Hypothalamus releases gonadotropin releasing hormone (GnRH) in a pulsatile manner
GnRH stimulates the release of FSH + LH from the anterior pituitary
FSH + LH act on the gonads (ovaries/testes) to stimulate synthesis and release of sex hormones
–> oestrogen, progesterone + testosterone

Question 3

What is the first sign of puberty in females are when does it usually occur?

Answer 3

Thelarche –> breast buds develop

Around age 9-10

Question 4

Which staging system is used to stage puberty?

Answer 4

Tanner staging

Question 5

What is the second sign of puberty in females?

Answer 5

Pubarche –> growth of pubic hair

Question 6

What is the third stage of puberty in females?

Answer 6

Menarche –> first menstrual period

Question 7

What is the first sign of puberty in males?

Answer 7

Increase in testicular size

Question 8

Where is testosterone synthesised in males?

Answer 8

By Leydig cells in testes

Question 9

What are the other signs of puberty in males?

Answer 9

Enlargement of the penis

Growth of pubic hair

Question 10

When is puberty considered precocious?

Answer 10

Development of secondary sexual characteristics

• before age 8 in girls
• before age 9 in boys

Question 11

When is puberty considered delayed/absent?

Answer 11

Absence of secondary sexual characteristics by the age of:

• 13 in girls
• 16 in boys

Question 12

What are the phases of the ovarian cycle during a menstrual cycle?

Answer 12

Follicular phase
Ovulation
Luteal phase

Question 13

What happens during the follicular phase?

Answer 13

Follicles mature and grow
Increase in FSH + LH stimulate follicular growth and oestrogen production
Oestrogen levels rise
One dominant follicle continues to maturity
Finally –> LH surge

Question 14

What happens in the ovulation phase?

Answer 14

LH surge –> follicle ruptures + mature oocyte is assisted to fallopian tubes by fimbria
The follicle continues secreting oestrogen + now progesterone - stalls cycle in anticipation of fertilisation

Question 15

How long does the oocyte remain viable for fertilisation?

Answer 15

about 24 hours

Question 16

What is the corpus luteum?

Answer 16

Tissue in the ovary that forms at the sight of a ruptured follicle following ovulation

Question 17

What happens in the luteal phase?

Answer 17

Corpus luteum produces oestrogen, progesterone + inhibin to maintain conditions for fertilisation + implantation
In absence of fertilisation –> corpus luteum regresses after 14 days
–> significant fall in hormones

Question 18

What happens to the corpus luteum if fertilisation occurs?

Answer 18

The syncytiotrophoblast of the embryo produces human chorionic gonadotrophin (HcG) –> exerts luteinising effect and maintains the corpus luteum (produces hormones to support pregnancy)

Question 19

What are the phases of the uterine cycle?

Answer 19

Proliferative phase
Secretory phase
Menses

Question 20

Which hormone is responsible for the proliferative phase of the uterine cycle?

Answer 20

Oestrogen

Question 21

What happens during the proliferative phase of the uterine cycle?

Answer 21

Occurs along side the follicular phase of ovarian cycle
–> preparing for fertilisation + implantation
Oestrogen initiates:
- thickening of endometrium
- growth + motility of myometrium
- production of a thin alkaline cervical mucus (to facilitate sperm transport)

Question 22

Which hormone is responsible for the secretory phase of the uterine cycle?

Answer 22

Progesterone

Question 23

What happens in the secretory phase of the uterine cycle?

Answer 23

Occurs alongside the luteal phase
Progesterone stimulates:
- further endometrial thickening into glandular secretory form
- thickening of myometrium
- reduced motility of myometrium
- thick, acidic cervial mucus production (hostile to sperm - prevents polyspermy)

Question 24

What happens during menses?

Answer 24

In the absence of fertilisation, once corpus luteum has broken down –> lining of uterus is shed

Question 25

What is considered a normal volume of blood loss during menses?

Answer 25

10-80 mls

Question 26

What is the average age of menopause (final menarche)?

Answer 26

51

Question 27

Which hormone change characterises the menopause?

Answer 27

Reduction in oestrogen

+ increase in FSH and LH

Question 28

Which symptoms are associated with the perimenopause/menopause?

Answer 28

Hot flushes
Urinary incontinence
Increased UTIs
Irregular vaginal bleeding
Dyspareunia (due to vaginal atrophy with drop in oestrogen)
Reduced bone mass

Question 29

How is the menopause defined?

Answer 29

Amenorrhoea for 12 months

Question 30

What is considered ‘early menopause’?

Answer 30

Age between 40 - 45

Question 31

How is the menopause ‘diagnosed’?

Answer 31

Serum FSH > 40

Question 32

Which treatment can be offered for women who cannot tolerate the symptoms of menopause?

Answer 32

HRT

• tablets
• transdermal patches
• oestrogenic vaginal ring

Question 33

What are the risks associated with HRT?

Answer 33

Increased risk of breast, endometrial + ovarian cancers

Increased risk of VTE + ischaemic stroke

Question 34

Where does conception usually occur?

Answer 34

Ampulla of the fallopian tube