The Developing Human 8Th Ed., Moore Ch. 2

Front 1

Gestational (menstrual) age

Back 1

Stages and duration of pregnancy begins w/ commencement of the mother's last normal menstrual period. Thus overestimates fertilization age by 2 weeks.

Front 2

First Meiotic Division

Back 2

Reduction Division: Homologous Chromosomes (one from each parent) pair at pro-phase and randomly separate during anaphase. Chromosomes are double stranded before and after the first division

Front 3

Second Meiotic division

Back 3

Similar to first phase except this time double stranded chromosomes separate to yield single stranded chromosomes. haploid number of chromosomes (23) is retained.

Front 4

Spermatogenesis
First Meiotic Division

Back 4

Takes 2 weeks to complete, spermatogonia (developed during fetal period) being to mature once puberty occurs. They are transformed into primary spermatocytes (largest germ cells in seminiferous tubules) and first meiotic division reduces ploidy by half, 46 to 23.

Front 5

Spermatogenesis
Second meiotic division

Back 5

Haploid Secondary spermatocytes undergo second meiotic division forming four haploid spermatids 1/2 size of secondary spermatocytes.

Front 6

Spermiogenesis

Back 6

Final maturation process transforming spermatids into four mature sperm. Entire process takes approx. 2 months

Front 7

Primary Oocytes

Back 7

formed from oogonia (proliferate via mitosis) before birth.

Front 8

Primordial Follicle

Back 8

Primary oocyte surrounded by connective tissue cells that form a single celled layer of flattened epithelial cells

Front 9

Primary Follicle

Back 9

As primary oocytes enlarge during puberty, follicular epithelial cells become cuboidal, then columnar.

Primary oocyte undergoes first meiotic division before birth, but prophase is not completed until puberty.

Front 10

Oocyte maturation Inhibitor

Back 10

follicular cells surrounding primary oocyte believed to secrete this substance to keep meiotic process arrested.

Front 11

dictyotene

Back 11

primary oocytes suspended in prophase

Front 12

When is first polar body formed?

Back 12

Shortly before ovulation, first meiotic division is completed and first polar body is formed along w/ much larger secondary oocyte.

Front 13

When does secondary oocyte complete second division?

Back 13

Begins at ovulation and progresses to metaphase, and then arrested. Only completed if and when it becomes fertilized by a sperm.

Front 14

When is oocyte maturation completed?

Back 14

Only after the secondary oocyte becomes fertilized and then after the second polar body is released.

Front 15

How many oocytes in newborn female?

Back 15

roughly two million primary oocytes, but most regress during childhood, at adolescence- no more than 40,000

Front 16

How many primary oocytes are expelled at ovulation throughout a woman's lifetime?

Back 16

about 400

Front 17

What is considered ideal age range for a female reproduction?

Back 17

18-35

Front 18

What is the percentage of sperm that are ejaculated that are usually abnormal?

Back 18

roughly 10%

Front 19

What percentage of sperm must be abnormal for their to be an appreciable effect on fertility?

Back 19

20%

Front 20

What endometrial layer is shed during menstruation?

Back 20

Functional layer- at its peak 4-5mm thick

Front 21

Where is GRH (Gonadotropin Releasing Hormone) made?

Back 21

synthesized by neurosecretory cells in the hypothalamus carried by hypophysial portal system to the anterior lobe of the pituitary gland.

Front 22

What does GRH do?

Back 22

Causes Ant. pituitary to release FSH and LH.

Front 23

Where are FSH and LH made?

Back 23

anterior pituitary

Front 24

What does FSH do to the ovary?

Back 24

Stimulates development of ovarian follicles and production of Estrogen by follicular cells

Front 25

What does LH do to the ovary?

Back 25

"Trigger" for ovulation (release of secondary oocyte) and stimulates follicular cells and corpus luteum to produce Progesterone

Front 26

How many primordial follicles begin to grow due to FSH stimulation?

Back 26

several grow forming 5-12 primary follicles, typically only 1 develops into mature follicle though.

Front 27

Theca Folliculi

Back 27

Connective tissue surrounding growing primary follicle organized into a capsule. Differentiates into 2 layers.

Front 28

Theca Interna

Back 28

Internal vascular & glandular layer. produces follicular fluid and some estrogen. Also secretes androgens that pass to follicular cells where they are made into estrogen

Front 29

Theca Externa

Back 29

Capsule like layer, thecal layers thought to produce angigenesis factor

Front 30

Antrum

Back 30

Fluid filled spaces around follicular cells, contains follicular fluid. Once antrum is formed, ovarian follicle is termed a vesicular or secondary follicle.

Front 31

When is a secondary follicle present?

Back 31

Once the antrum is formed

Front 32

Cumulus Oophorus

Back 32

primary oocyte is pushed to one side of the follicle where it becomes surrounded with follicular cells, the cumulus oophorus that projects into the antrum.

Front 33

What induces early stages of follicle development?

Back 33

FSH

Front 34

What induces final stages of follicle development?

Back 34

LH as well as FSH

Front 35

What do follicles produce?

Back 35

Estrogen, that then in turn regulates development and function of reproductive organs.

Front 36

What are interstitial glands of the ovary, and what do they produce?

Back 36

They are widely scattered groups of stromal secretory cells that produce estrogen

Front 37

Stigma

Back 37

small avascular spot that appears on ovarian follicle swelling. Stigma balloons out and forms a vesicle shortly following LH surge and before ovulation.

Front 38

What causes LH surge and what does it do?

Back 38

High blood estrogen levels cause the LH surge, this in turn causes ovulation 12 to 24 hours later. It also induces the the resumption of the first meiotic division of the primary oocyte.

Front 39

What do mature ovarian follicles contain?

Back 39

Since LH surge induces resumption of first meiotic division, it contains a secondary oocyte.

Front 40

What surrounds the expelled secondary oocyte?

Back 40

The corona radiata, which is the zona pellucida and one or more layers of follicular cells that are radially organized-forming oocyte-cumulus complex.

Front 41

What is the zona pellucida composed of?

Back 41

Three glycoproteins, ZPA, ZPB, & ZPC that form a thick network of filaments with multiple pores.

Front 42

Mittelschmerz

Back 42

variable amount of abdominal pain that accompanies ovulation in some women due to the release of some blood into the peritoneal cavity (caused by ovulation)

Front 43

Signs that ovulation has occurred?

Back 43

Mittelschmerz or more accurately a slight drop in basal body temperature

Front 44

Anovulation

Back 44

some women do not ovulate due to inadequate release of gonadotropins. In some women, gonadotropins or an ovulatory agent such as clomiphene citrate can be given to induce ovulation.

Front 45

clomiphene citrate

Back 45

Stimulates release of pituitary gonadotropins (FSH & LH) and results in the maturation and subsequent ovulation of multiple follicles. Spontaneous abortions occur because no more than 7 embryos can survive.