Female Reprodictive Anatomy & Physiology

Question 1

What makes up the female reproductive system?
(6 points)

Answer 1

• Gonads (ovaries - gamete production + production of sex hormones)
• Fallopian tubes (carry developing oocytes from ovary to uterus + for sperm transport)
• Uterus (house + support growth of embryo/foetus)
• Cervix (allows passage of sperm)
• Vagina
• Vulva (external genitalia)

Question 2

Where does fertilisation take place?

Answer 2

Fallopian tubes

Question 3

What does the vulva comprise of?
(4 points)

Answer 3

• Mons pubis (layer of fatty tissue overlying pubic bone)
• Labia (labia majora/minora)
• Urethral meatus (opening)
• Clitoris

Question 4

What 2 hormones are produced by the ovaries?

Answer 4

Oestrogen
Progesterone

Question 5

What connective tissue surrounds the ovaries?

Answer 5

Tunica albuginea

Question 6

What does the main ovary comprise of?

Answer 6

• Outer cortex (primordial follicles)
• Central medulla (connective tissue + blood vessels)
• Inner hilum

Question 7

What is the role of the fallopian tubes?

Answer 7

• Carries ovum from ovary
• Facilitates sperm movement

Question 8

How is the movement of oocytes through the fallopian tubes aided?

Answer 8

• Fimbria (cilia-covered, fringe-liked stucture that sweeps ovulated ovum into tube)
• Contractions of wall of tubes

Question 9

What is the uterus surrounded by?

Answer 9

• Peritoneum
• Perimetrium

Question 10

What 2 muscles are in the uterus?

Answer 10

• Myometrium (smooth muscle + vascular tissue)
• Endometrium (inner cavity)

Question 11

What is the role of the uterine glands?

Answer 11

Provide nourishment (proteins) for embryo until placenta is established

Question 12

What happens during the oestrous cycle?

Answer 12

Pro-oestrus:
- Follicle start developing
- Secretes oestrogen
- Endometrium develops

Oestrus:
- In heat
- Female is sexually receptive/ready for mating
- Might be visible through various signs, e.g. reddening of labia

Metoestrus:
- Lutueal phase
- Corpus luteum develops from ruptured follicle after ovulation

Dioestrus:
- Corpus luteum produces progesterone
- Prepares uterus for implantation
- In the absence of pregnancy, corpus luteum degenerates
- Endometrium is reabsorbed for next cycle

Anoestrus:
- Sexual inactivity
- Induced by pregnancy, lactation, illness, age & seasons/time of the year in seasonal breeders
- In seasonal breeders, it is controlled through exposure to light that influences the release of melatonin from pineal glands

Question 13

Give 2 examples of other animals that have a menstrual cycle

Answer 13

• Elephant shrew
• Spiny mouse

Question 14

What happens to those species with an oestrous cycle rather than a menstrual cycle?

Answer 14

Endometrium is reabsorbed

Question 15

What is a duplex uterus?

Answer 15

2 distinct uteri (open separately into vagina)

Question 16

What is a bipartite uterus?

Answer 16

Partial septum separating uteri

Question 17

What is a bicornuate uterus?

Answer 17

No septum

Question 18

What is the cervix?

Answer 18

• The narrow, lower portion of uterus
• Soft with an abundant, thin, mucus secretion just before ovulation (to facilitate sperm movement)

Question 19

What happens to the cervix after ovulation?

Answer 19

• Closes up
• Becomes harder
• Cervical secretions are thicker + stickier

Question 20

What is the role of the vagina?

Answer 20

• Muscular tube for receiving male penis
• Provides passage of foetus at parturition

Question 21

What is the role of the Bartholin’s glands + where are they?

Answer 21

• Secrete mucous to lubricate vagina
• Lie slightly posterior + to left/right of vaginal opening

Question 22

What 2 phases does the menstural cycle consist of?

Answer 22

• Follicular phase
• Luteal phase

Question 23

What happens in the follicular phase?

Answer 23

• Hypothalamus secretes GnRH
• GnRH acts on anterior pituitary gland to secrete FSH & LH
• FSH stimulates follicles in ovary
• Oestrogen secreted from granulosa cells in ovary
• Oestrogen will thicken endometrium & thin cervical mucous to prepare for fertilisation
• Oestrogen acts in a negative feedback loop on the hypothalamus so that FSH isn’t continuously released & only 1 dominant follicle continues developing
• LH released for ovulation at day 14

Question 24

What happens in the luteal phase?

Answer 24

• Corpus luteum produces progesterone + oestrogen
• Progesterone will thicken endometrium & thin cervical mucous for fertilisation
• Oestrogen & progesterone acts in a negative feedback loop to reduce FSH & LH

If fertilisation occurs:
- HCG is released from early embryo
- HCG maintains corpus luteum
- Progesterone & oestrogen remain high to support pregnancy
- LH & FSH remain low to prevent further ovulation
- At 6 weeks, placenta takes over oestrogen & progesterone
- Corpus luteum degenerates

If fertilisation doesn’t occur:
- No HCG
- Corpus luteum degenerates
- Decreased oestrogen + progesterone
- Break down of endometrium
- No negative feedback loop so FSH & LH increase
- Cycle stars again

Question 25

What does high oestrogen cause prior to ovulation?

Answer 25

- Thickens endometrium - Thins cervical mucous

Question 26

When does the endometrium develop in the menstrual cycle?

Answer 26

- First 4 days - In follicular phase, under the influence of oestrogen

Question 27

What happens within the last 4 days of the menstrual cycle?

Answer 27

- Endometrium disintegrates - Bleeding occurs from ruptured blood vessels in endometrium - Blood + disintegrating outer layers of endometrium expelled as menstrual fluid

Question 28

Describe the development of the endometrium throughout the menstrual cycle

Answer 28

Follicular phase: - High oestrogen thickens endometrium Luteal Phase: - High oestrogen/progesterone from corpus luteum thicken endometrium - If fertilisation doesn’t occur, corpus luteum degenerates - Progesterone/oestrogen decrease - Endometrium breaks down = menstrual bleeding

Question 29

In non-human mammals, what 4 phases are part of the oestrous cycle?

Answer 29

1- Oestrus 2- Metoestrus 3- Dioestrus 4- Prooestrus

Question 30

What is the oestrus phase?

Answer 30

- In heat - Female is sexually receptive/ready for mating - Might be visible through various signs, e.g. reddening of labia

Question 31

What are induced ovulations? Give an example.

Answer 31

Ovulation is induced by mating E.g. cats, camels, llamas, etc.

Question 32

What is the metoestrus phase?

Answer 32

- Lutueal phase - Corpus luteum develops from ruptured follicle after ovulation

Question 33

What is the dioestrus phase?

Answer 33

- Corpus luteum produces progesterone - Prepares uterus for implantation - In the absence of pregnancy, corpus luteum degenerates - Endometrium is reabsorbed for next

Question 34

What is the pro-oestrus phase?

Answer 34

Pro-oestrus: - Follicle start developing - Secretes oestrogen - Endometrium develops

Question 35

What is the anoestrus phase?

Answer 35

- Sexual inactivity - Induced by pregnancy, lactation, illness, age & seasons/time of the year in seasonal breeders - In seasonal breeders, it is controlled through exposure to light that influences the release of melatonin from pineal glands

Question 36

What is an ectopic pregnancy?

Answer 36

A complication in pregnancy in which embryo attaches/implants outside uterus, most often in fallopian tubes

Question 37

What are some symptoms of ectopic pregnancies?

Answer 37

- Cramping - Abdominal pain - Vaginal bleeding

Question 38

What are the outcomes of ectopic pregnancies?

Answer 38

- Uterine tube not large enough - Lack of blood supply for placenta - Death of embryo

Question 39

What is amenorrhoea?

Answer 39

Failure to menstruate normally between puberty + menopause

Question 40

What is primary amenorrhoea?

Answer 40

If not started by 16 years old

Question 41

What is secondary amenorrhoea?

Answer 41

If no period for >3 months (outside of contraception, pregnancy, or lactation)

Question 42

What is amenorrhoea caused by?

Answer 42

- Chromosomal abnormalities - Hormone imbalance - Excessive exercise

Question 43

What is dysmenorrhoea?

Answer 43

Period pains

Question 44

What is hypogonadism in females?

Answer 44

Under activity, development failure, or absence of ovaries, leading to low levels of female sex hormones

Question 45

What can cause hypogonadism?

Answer 45

- Chromosomal abnormality - Abnormality of pituitary gland or hypothalamus

Question 46

How can hypogonadism be treated?

Answer 46

- Human growth hormone injections - Oestrogen injections (HRT)

Question 47

Give an example of delayed fertilisation.

Answer 47

Bats: - Copulation may occur at any time, most often before winter hibernation - Sperm kept nourished by uterine secretions for at least 200 days + females ovulate at a time favourable to gestation + birth - Adaptation to winter dormancy

Question 48

Give an example of delayed implantation

Answer 48

Bears: - Zygote undergoes normal cleavage but then blastocyst development is arrested - blastocyst remains in ‘dormant’ state + doesn’t implant but floats freely in uterus - Likely an adaptation to facilitate diving birth at optimal time of year

Question 49

Give an example of a species showing some unusual female adaptations.

Answer 49

Spotted hyenas: - Sex roles reversed —> f larger + more aggressive than m - Dominant social group - F genitals look more like a penis but it is actually the clitoris (vaginal canal turns back on itself and exits the body) - Also pass high levels of androgens to offspring that make cubs more aggressive + sexually vigorous

Question 50

Give 4 differences between the menstrual cycle & oestrus cycle

Answer 50

1. MS occurs in primates, OS in non-primates 2. Endometrium shed in MS, reabsorbed in OS 3. F sexually active throughout MS, f only sexually active during oestrus phase in OS 4. Ovulation is concealed in MS, visible physiological & behavioural changes in OS