Pregnant Uterus Flashcards
What is the role of reproductive system is to?
Produce a gamete called oocyte and prepare for implantation
What is the hormone that controls the reproductive cycle
Gonadotrophic hormone: it is released from hypothalamus then to anterior pituitary gland then releases luthenizing hormone (LH) and (FSH)
How is GnRH released
Through pulse frequency of ovarian cycle
What increases the pulse frequencies of ovarian cycle
Oestrogen
What decreases pulse frequencies
Progesterone
What does the increased frequencies allow
For the production of (fsh) and (lh)
After How many days does a switch over from inhibitions to secretion of (LH) by oestrogen occur
After day 10 after 36 hours of High levels of oestrogen
What happens on day 14 of her ovarian cycle
Surge of (LH) breaks follicular wall and allow corpus luteum to be released for ovulation
Name the two phases in ovarian cycle
lateal and follicular phase
What is the most abundant oestrogen produced in ovarian
Estradiol (most dominant on tissues prior to pregnancy)
How is estradiol produced
It is produced by cholesterol converted to androstenedione which then makes testosterone, testosterone then through aromatase becomes estradiol. Other oestrogens are produced directly from androstenedione through aromatase
What are the functions of oestrogen
- It has effect on CNS (sexual drive)
- stimulation of bone and muscle growth
- establishment and maintenance of female secondary sex characteristics
- maintenance of accessory reproductive glands and organs
- NB stimulation of endometrial growth and secretion
What happens on day 14
- LH allows for release of follicle for ovulation
- increase levels of progesterone * which produces corpus luteum
(LH maintains corpus luteum maturation), (prosesterone level decrease after day 21 if no pregnancy decreasing progesterone levels releases carpus albicans )
During which uterine phase is there destruction of functional zone
Menstrual phase for up to 7 days
What happens in the uterine e cycle during proliterative phase
After day 7 due to the rising oestrogen levels there is repair and regeneration of functional zone
What happens during secretary phase
Rising progesterone levels from day 14 allow uterine glands to secrete proteins, lipids and glycogen. The glands also become increasingly elongated and sacculated.
When does fertilisation take place
1 day after ovulation
Where does fertilization occur
In uterine tubes
Name the first and second layer of oocyte
- Zone pellucida
2. Corona radiata
fertilization can be divided into which steps
Acrosome reaction
Oocyte activation
Cortical reaction
What happens in acrosome reaction
The head piece of the sperm when reaches oocyte releases digestive hormones such as hyaluronidase and acrosine (protein digesting enzyme) digest the corona radiata of the ovum creating gaps allowing the sperm to pass towards the zone pellucida
What happens after a single cell enters an oocyte
There is membrane fusion which results in activation of oocyte and completion of meiosis by oocyte
What is involved in oocyte activation
The entrance of sodium ions into the oocyte which results in the depolarization of the membrane
Calcium entrance released from SER resulting in exocytosis of vesicles that are adjacent to occyte membrane this then leads to the completion of meiosis 2 and formation of second polar body
What happens during cortical reaction
The is a release of enzyme by oocyte that will inactivate the sperm receptors on the surface of the oocyte, there will also be hardening of the Zola pellucida
