Reproductive System Flashcards
How is the vagina lubricated?
Mucus secreted by the greater vestibular glands
How long does it take an oocyte to reach the uterus?
3-4 days
How does the oocyte move into the fallopian tubes?
Undulating fimbraie
What are the layers of the uterus called?
- Endometrium (inner)
- Myometrium (middle)
- Perimetrium (outer)
What holds the uterus in place?
- Uterosacral ligament
- Round ligament
Where does implantation occur?
Endometrium
Which layer contracts during labour?
Myometrium
What is the function of the perimetrium?
Protects the uterus from friction
Describe the life cycle of follicles
- Contain an oocyte
- As they mature, they grow a fluid filled area called an antrum = Graafian follicle
- When ovulation occurs, the ruptured follicle develops into a corpus luteum
What are the 3 phases of the ovarian cycle?
- Follicular phase
- Ovulation
- Luteal phase
Describe the follicular phase
- Release of FSH and growth of primary follicles
- Oestrogen released
- As oestrogen increases, FSH decreases
- 1st meiotic division
Describe ovulation
- Critical levels of oestrogen result in the release of LH
- 2nd meiotic division occurs but is halted at metaphase II
Describe the luteal phase
- LH forms the corpus luteum which releases oestrogen and progesterone
- These cancel out FSH and LH
- If fertilisation doesn’t occur, oestrogen and progesterone decrease and FSH increases to repeat the cycle
What are the 3 phases of the uterine cycle?
- Menstrual phase
- Proliferative phase
- Secretory phase
Describe the menstrual phase
- Functional layer of endometrium shed (menses)
- Oestrogen and progesterone low = FSH increases
Describe the proliferative phase
- Oestrogen repairs functional endometrium
- Blood supply to endometrium increases
Describe the secretory phase
- Corpus luteum secretes oestrogen and progesterone
- Blood and nutrients increase to support embryo
- Corpus luteum degenerates
- If fertilisation doesn’t occur, cell death of endometrium occurs
When in the cycle does ovulation usually occur?
Day 13-15
Name 3 female reproductive disorders
- Pelvic Inflammatory Disease
- Endometriosis
- Polycystic Ovary Syndrome
Describe pelvic inflammatory disease
- Infection in the genital tract caused by bacteria or an STI
- Affects uterus, ovaries and fallopian tubes
- Increases risk of ectopic pregnancy
- Treated with antibiotics
Describe endometriosis
- Endometrial tissue found in places other than the uterus
- Can cause infertility
- Can’t be cured but give pain relief, reduce oestrogen to reduce endometrial growth and can have surgery to remove tissue
What is polycystic ovary syndrome?
- Cysts on ovaries
- Causes irregular periods (which may cause anovulation) and excess androgen (which may cause excess body/facial hair etc)
- Difficult to conceive
- No cure
How many times does a sex cell undergo meiosis?
2
What are the 5 stages of meiosis?
- Interphase
- Prophase
- Metaphase
- Anaphase
- Telophase
What happens in interphase?
- Only occurs in meiosis I
- Duplication of oogonia by mitosis
What happens in prophase I?
- Chromosomes condense
- Homologous pairs formed
- Crossing over
- Spindles form
What happens in metaphase I?
- Pairs line up at the equator
- Spindles attach to pairs
- Random assortment
What happens in anaphase I?
- Homologous pairs are pulled apart to opposite poles
What happens in telophase I?
- Nuclear membrane reforms with 2 haploid cells
What happens in prophase II?
- Chromosomes condense
- Nuclear envelope breaks
- Spindles form
What happens in metaphase II?
- Chromosomes line up at the equator
- Spindles attach to chromosomes
- Meiosis II stops at this stage unless the egg is fertilised
What happens in anaphase II?
- Sister chromatids are pulled apart as a result of fertilisation
What happens in telophase II?
- Nuclear membrane reforms
- Chromosomes decondense
- Cytokinesis (cytoplasm divides into 2 daughter cells)
