04 oocyte follicles etc

Question 1

Folliculogenesis

Answer 1

interwoven with oogenesis

Question 2

Primordial germ cells

Answer 2

stem cells of oogenesis

migrate from yolk sac and multiply by mitosis

Question 3

Oogonia

Answer 3

once primordial germ cells reach genital ridge and loose their motility–> now called oogonia
interconnected by cytoplasmic bridges
multiply by mitosis

Question 4

Primary oocyte

Answer 4

Following mitosis and once meiosis occurs it is called a primary oocyte

Question 5

Primordial follicle

Answer 5

formation occurs during fetal life
pool of resting follicles which are progressively depleted during the life of the female
oocyte loses the intracellular bridges and are enclosed in a single layer of granulosa cells

Question 6

Primary follicle

Answer 6

primary oocyte activates, enlarges, begins to produce zona pellucida. Follicular cells become cuboidal; stromal cells form theca.

Question 7

Secondary follicle

Answer 7

Oocyte surrounded by many layers of granulosa cells
Zona pellucida is now visible.
Thecal layers begin to elaborate
Follicle has own blood supply
Is sensitive to hormonal regulation

Question 8

Tertiary or Antral follicle

Answer 8

Follicular fluid formed from granulosa cells and blood filtrate accumulates in spaces. When the spaces merge it is an antrum. Granulosa differentiated into columnar corona radiata cells, cumulus cells, and membrana granulosa cells.
Theca interna and externa are also present.

Question 9

Theca interna

Answer 9

epithelioid steroidogenic cells, blood and lymph capillaries
LH responsive
produces androgen (testosterone)

Question 10

Granulosa cell

Answer 10

FSH responsive
aromatose androgen (testosterone)–>estradiol
Estradiol increases as follicles grow

Question 11

Theca externa

Answer 11

Fibroblastic layer; thecal cone points towards ovarian surface.

Question 12

Pre-ovulatory of Graafian follicle

Answer 12

Fluid filled cavity has reached its max size

Oocyte is located eccentrically within the antrum

Question 13

Corpus hemorrhagicum

Answer 13

results from ruptured blood vessels following ovulation

Question 14

To form the corpus luteum the

Answer 14

granulosa cells become granulosa lutein cells
Theca interna become theca lutein cells
Luteinization= hypertrphy, hyperplasia, accumulation of lipid pigment

Question 15

What does the corpus luteum produce

Answer 15

progesterone

Question 16

corpus albicans

Answer 16

If pregnancy doesn’t occur the corpus luteum degenerates and is invaded by connective tissue.

Question 17

corpus atreticum

Answer 17

forms from follicles that fail to complete development.

Question 18

Endometrium

Answer 18

tunica mucosa of the uterus. Contains uterine glands, and lamina propria which is hyperplastic loose connective tissue

Question 19

Myometrium

Answer 19

tunic muscularis of uterus. Thick inner circle of smooth muscle

Question 20

Perimetrium

Answer 20

tunica serosa of uterus

Question 21

Meiosis produces haploid cells. Diploidy is restored after

Answer 21

union of male and female gametes at fertilization

Question 22

1st meitotic division

Answer 22

synthesis phase

Question 23

The first meiotic division has a long prophase that can be divided into 5 stages

Answer 23

leptotene, zygotene, pachytene, diplotene, diakinesis

Question 24

Leptotene

Answer 24

The chromatic of the chromatids is stretched out very thinly and condensation begins

Question 25

Zygotene

Answer 25

homologous chromosomes pair side by side; this pairing is called synapsis and characteristic of meiosis . Require a synaptonemal complex

Question 26

Pachytene

Answer 26

the chromatids thicken and shorten, crossing over may occur which leads to genetic recombination

Question 27

Diplotene

Answer 27

- the synaptonemal complex breaks down and the two homologous chromosomes start to separate - they may remain attached at various places called chiasmata - high level of gene transcription

Question 28

1st meotic arrest

Answer 28

at end of diplotene arrests from birth until close to ovulation resumption is dependent on LH

Question 29

Diakinesis

Answer 29

occurs after LH surge at first ovulation - the centromeres move away from each other - ends with the breakdown of the nuclear membrane germinal vesicle and the migration of the chromosomes to the metaphase plate

Question 30

After going through the 5 stages of prophase meiosis 1 continues to go through the stages of

Answer 30

Metaphase I, Ananphase I, Telophase I

Question 31

Interkinesis/Interphase II

Answer 31

No DNA replication occurs

Question 32

2nd meiotic division

Answer 32

``` Similar to mitosis- no DNA replication Prophase II Metaphase II Anaphase II Telophase II ```

Question 33

2nd meiotic arrest

Answer 33

occurs at Metaphase II | Meiosis is only completed after fertilization

Question 34

Two hormones that regulate follicular developments

Answer 34

FSH and LH

Question 35

Where are FSH receptors located on the follicle

Answer 35

granulosa cells

Question 36

Where are LH cells located on the follicle

Answer 36

initially only on thecal cells and in late stages also on granulosa cells