Animal reproduction- 46 pt. 2 female

secondary oocyte

An oocyte in which the first meiotic division is completed. It leaves its follicle and also the uterus and will wait on the felupian tube. it stops in metaphase of meiosis 2 and wait for fertilization.

LH & FSH in the ovarian cycle

Both rise just before ovulation; FSH stimulates the growth and recruitment of immature ovarian follicles in the ovary. LH- triggers ovulation and development of the corpus luteum.

phases of menstrual cycle

Menstruation (bleeding)-> Follicular phase-> ovulation -> Luteal (of corpus luteum) phase

What happens in the uterus in the follicular phase?

Menstruation phase- Endometrium leaves through the vagina. Proliferative phase- estrogen stimulated growth of new endometrium thickens & spiral arteries grow.

Internal female sex organs

Ovaries- the gonads Felobian tubes uterus & cervix

What is corpus luteum made of?

Theca & Grandulosa cells. they continue to secrete hormones. more progesterone is secreted. when it degenrates- corpus albicans (no hormones)

uterus location

between bladder and rectum

secondary follicle

in the 2nd of follicular development. (oocyte still in prophase 1) theca cells formed- they secrete estrogen & have receptors for LH. more granulosa cells- secretion of hormones, nourishment of the oocyte.

two layers of the ovaries?

outer ovarian Cortex- holds most of the follicles. at birth more than 2 mil. follicles! (Primordial follicles) only 400 will pass meiosis 1. inner medulla- contain blood vessels.

What is Endomitrium and what happens to it in the menstrual cycle?

- It is a mucosal layer in the inner part of the uterus which goes monthly changes. during the follicular phase it is thickens, and during the luteal phase arteries are formes to nourish it, if there is no fertilization it is removed.

2nd step of follicular development

Primary follicles evolve into secondary (theca cells & more granulosa cells, oocyte still in prophase 1) then tertiary AKA graafian follicles (Antrum space formed around oocyte, granulosa secrete nourishing liquid)

follicular phase

The first phase of the ovarian cycle, during which a follicle (an oocyte and its surroudning cells) enlarges and matures. This phase is under the control of FSH from the anterior pituitary, and typically lasts from day 1 to day 14 of the menstrual cycle. The follicle secretes estrogen during this time period. at the end of these stage ovulation occurs

How is the dominant follicle & oocyte selected?

The follicle with the most FSH receptors will be selected, other follicles will degenerate. the dominant follicle will secrete Estrogen which the hypothalamus will respond in LH & FSH, that will stimulate the dominant follicle to evolve, and the primary oocyte(46) will finish meiosis 1 and turn into a secondary oocyte(23).

Which follicle will become the dominant?

The follicle with the most FSH receptors.

luteal phase

The second phase of the ovarian cycle, the secondary oocyte has been secreted to the felupian tube, corpus luteum secrete inhibin, which slows the secretion of FH, LH & estrogen.

Ovarian follicle and oocyte

an ovarian follicle is a cellular aggregation around an oocyte, It secretes hormones that influence stages of the menstrual cycle. the dominant follicle will secrete it's oocyte for ovulation. (determined by amout of FSH receptors).

corpus luteum

empty ovarian follicle, created from the follicle after ovulation. composed of theca & granulosa cells. granulosa cells secrete inhibin which inhibits FSH, LH, estrogen Theca cells secrete progeserone. if there is fertilization- the corpus luteum continues to secrete progesterone until the placenta forms. if no fertilization- corpus luteum stops secretions, and dies.

1st step of follicular development

infancy to puberty- primary oocyte stays in prophase of meiosis 1. Primordial follicles (surrounds the primary oocyte) developed into primary follicles (they grow granulosa cells) .

What holds the ovaries in place?

series of ligament- Broad, suspensory & ovarian ligaments. The suspensory ligament is extremely important since blood vessels & nerves pass through it to reach the ovary.

3rd stage of follicular development (graafian phase)

tertiary follicles are ready, occurs durin the follicular phase.

Where fertilization occurs? how is the zygote gets to the uterus?

- it occurs in the ampullar region. - the fallopian tube inner layer is a smooth muscle covered in cilia which sweep the zygote to the uterus.

Two synchronized developments of menstrual cycle

1) The ovarian cycle- development of the oocyte & ovulation/ 2) Uterine cycle- functional endomitrium thickens & shed.

Stages of oocyte development

1) in embryo: Oogonium undergo mitosis-> Primary oocyte is formed, arrested in prophase of meiosis 1. 2) Puberty: Completion of meiosis 1. first polar body out (may duplicate)-> secondary oocyte. Arrested at metaphase 2, waiting for a sperm 3) Fertilization: Completion of meiosis 2, second polar body, the egg is now fertilized, therefore a zygote.

Hormonal aspects of the menstruation cycle regarding puberty

Before puberty- GnRH secreted constantly from the hypothalamus. after puberty- GnRH secreted in pulses. GnRH stimulated secretion of LH & FSH from the pituitary; LH binds to Theca cells that produce Progesterone. FSH - stimulate the production of estrogen.

Estrogen & Progesterone in the menstrual cycle

Estrogen (estradiol)- peaks and causes LH to rise; after ovulation, it rises again to cause the endometrium to thickens. Progesterone- Helps Estrogen to thickens the endometrium. Both hormones secreted from the ovaries and the corpus luteum, when it degenerates, there is no secretion of these hormones, therefore the endometrium will also degenerate. This is also the reason they are the only hormones called female sex hormones, because they are secreted in the gonads.

What happens to the hormones level in days 13-14? why?

Estrogen secreted from the follicle stimulate the anterior pituitary to release more FSH & LH. thus FSH & LH peak. thats induces ovulation.

What happens to the oocyte during the follicular phase and how?

FSH & LH from the anterior pituitary stimulate the follicle; in the follicle are Theca cells- receive LH and in response release Andostenedine. and Granulosa cells which receive FSH and LH release Estrogen.

Uterus structure

Fundus- space in which the fallopian tubes are connected. uterine body- the hollow space Cervix- seperates the uterus & the vagina. plugged with mucus. opens only in menstruation & ovulation. the uterus supported by ligaments.

What are the roles of inhibin & progesterone?

- Acts as a negative feedback on the pituitary, decreases the release of LH & FSH. - Progesterone also makes the endomerium prepare for a fertlized zygote. when there is no progesterone- Endometrium collapses.