Week Seven

Question 1

Function of the Ovaries

Answer 1

• To release oocytes

- To produce steroid hormones oestrogen and progesterone

Question 2

Menstrual Cycle

Answer 2

1. Under the influence of the nerves in the hypothalamus gonadotrophin releasing hormone is released
2. Glands of the pituitary release Follicle Stimulating Hormone
3. Growth of an ovarian follicle stimulated
4. Lutenising hormone released, triggers ovulation
5. The remaining follicle is converted into the corpus luteum
6. Cells of the corpus luteum secrete progesterone
7. Endometrium undergoes changes. Follicular phase the developing follicle produces increasing level of oestrogen which regenerates the endometrium
8. In the luteal phase the corpus luteum secretes progesterone for several days
9. When egg is not fertilised the corpus luteum withers, the levels of progesterone and oestrogen drops and the endometrium is shed

Question 3

Embryonic Development

Answer 3

• Post-fertilisation age is used when discussing embryonic and foetal development
• The embryo begins to develop in the blatocyst on the 6th day past fertilisation
• During embryogenesis and organogenesis the cells migrate through the embryo and differentiate into specific cells types
• The foetal period begins at week 9

Question 4

The Placental Functions

Answer 4

• Provides nutrients to the baby from the mother
• Provides oxygen to the baby from the mother
• Disposes of waste products from the baby to the mother - Carbon Dioxide, Urea, Uric Acid & Bilirubin
• Produces hormones - Oestrogen, Progesterone, Prolactin, Relaxin, Prostaglandins, Oestriol
• Has an immunological function - Maternal Antigenic response does not occur
• Acts as a barrier against MOST bacteria

Question 5

Placental Circulation

Answer 5

• Substance exchange occurs via placental choronic villi
• Maternal blood enters the intervillous spaces
• Oxygenated blood goes to the baby via the umbilical vein
• Deoxygenated blood leaves the baby and goes to the maternal circulation via the two umbilical arteries
• Anything restricting uteroplacental circulation can reuse blood flow to the baby resulting in restricted growth, hypoxia or death

Question 6

Amniotic Fluid

Answer 6

• Provides space for the baby, symmetrical growth and movement
• Equal pressure protects baby from injury
• Constant temperature
• Some nutrients
• Prevents cord and placent from compression during contractions
• Aids cervical effacement and dilation