Chapter 3

Question 1

These ___ are controlled by the hypothalamus. Gonadotropin-releasing hormone (GnRH), produced by the hypothalamus, acts on cells of the anterior lobe (adenohypophysis) of the pituitary gland, which in turn secrete gonadotropins

Answer 1

sexual cycles

Question 2

These sexual cycles are controlled by the hypothalamus. Gonadotropin-releasing hormone (GnRH), produced by the hypothalamus, acts on cells of the anterior lobe (adenohypophysis) of the pituitary gland, which in turn secrete ____

Answer 2

gonadotropins

Question 2

These sexual cycles are controlled by the hypothalamus. ____, produced by the hypothalamus, acts on cells of the anterior lobe (adenohypophysis) of the pituitary gland, which in turn secrete gonadotropins

Answer 2

Gonadotropin-releasing hormone (GnRH)

Question 3

These hormones,____ and ____, stimulate and control cyclic changes in the ovary

Answer 3

follicle-stimulating hormone (FSH) - luteinizing hormone (LH)

Question 4

When a follicle becomes atretic, the oocyte and surrounding follicular cells degenerate and are replaced by connective tissue, forming a ____

Answer 4

corpus atreticum

Question 4

FSH also stimulates the maturation of ___ cells surrounding the oocyte

Answer 4

follicular (granulosa)

Question 5

In the meantime, the surface of the ovary begins to bulge locally, and at the apex, an avascular spot, the ___, appears.

Answer 5

stigma

Question 6

Those contractions extrude the oocyte, which together with its surrounding granulosa cells from the region of the cumulus oophorus breaks free (____) and floats out of the ovary

Answer 6

ovulation

Question 6

Some of the cumulus oophorus cells then rearrange themselves around the zona pellucida to form the ___

Answer 6

corona radiata

Question 7

Under the influence of LH, these cells develop a yellowish pigment and change into ___, which form the corpus luteum and secrete estrogens and progesterone

Answer 7

lutein cells

Question 8

Under the influence of LH, these cells develop a yellowish pigment and change into lutein cells, which form the corpus luteum and secrete estrogens and ___

Answer 8

progesterone

Question 8

Under the influence of LH, these cells develop a yellowish pigment and change into lutein cells, which form the ___ estrogens and progesterone

Answer 8

corpus luteum

Question 9

Progesterone, together with some estrogen, causes the uterine mucosa to enter the _____ in preparation for implantation of the embryo

Answer 9

progestational or secretory stage

Question 10

Subsequently, the corpus luteum shrinks because of degeneration of lutein cells (___) and forms a mass of fibrotic scar tissue, the ____

Answer 10

luteolysis - corpus albicans

Question 10

If the oocyte is fertilized, degeneration of the corpus luteum is prevented by ___, a hormone secreted by the syncytiotrophoblast of the developing embryo

Answer 10

human chorionic gonadotropin

Question 11

The corpus luteum continues to grow
and forms the ____ (corpus luteum graviditatis)

Answer 11

corpus luteum of pregnancy

Question 12

Fertilization, the process by which male and female gametes fuse, occurs in the ____

Answer 12

ampullary region of the uterine tube

Question 13

The corpus luteum continues to grow
and forms the corpus luteum of pregnancy (_____)

Answer 13

corpus luteum graviditatis

Question 14

____ is a period of conditioning in the female reproductive tract that in the human lasts approximately 7 hours

Answer 14

Capacitation

Question 14

Spermatozoa are not able to fertilize the oocyte immediately upon arrival in the female genital tract but must undergo;
1.
2.

Answer 14

(1) capacitation and (2) the acrosome reaction to acquire this capability

Question 15

The ____, which occurs after binding to the zona pellucida is induced by zona proteins

Answer 15

acrosome reaction

Question 16

The phases of fertilization include the following:

Answer 16

Phase 1, penetration of the corona radiata
Phase 2, penetration of the zona pellucida
Phase 3, fusion of the oocyte and sperm cell membranes

Question 17

This contact results in release of lysosomal enzymes from ___ lining the plasma membrane of the oocyte

Answer 17

cortical granules

Question 18

In turn, these enzymes alter properties of the zona pellucida (___) to prevent sperm penetration and inactivate species-specific receptor sites for spermatozoa on the zona surface

Answer 18

zona reaction

Question 19

The spermatozoon, meanwhile, moves forward until it lies close to the female pronucleus. Its nucleus becomes swollen and forms the ___

Answer 19

male pronucleus

Question 20

____ are another commonly used form of contraception.

Answer 20

Hormonal methods

Question 21

___ of contraception include the male condom, made of latex and often containing chemical spermicides, which fits over the penis, and the female condom, made of polyurethane, which lines the vagina

Answer 21

Barrier methods

Question 22

A ____ has been developed and tested in clinical trials. It contains a synthetic androgen that prevents both LH and FSH secretion and either stops sperm production [70% to 90% of men] or reduces it to a level of infertility.

Answer 22

male “pill”

Question 22

____ are used as birth control measures that may prevent pregnancy if taken 120 hours after sexual intercourse. These pills may be administered as high doses of progestin alone or in combination with estrogen [Plan B]

Answer 22

Emergency contraceptive pills [ECPs]

Question 23

The ____ is a small T—shaped unit and there are two types: hormonal and copper

Answer 23

intrauterine device [IUD]

Question 24

____ is another form of birth control. The method for men is a vasectomy, which prevents the release of sperm by blocking the ductus deferens, the tube that transports sperm from the testes to the penis. For women, it is tubal sterilization in which the uterine tubes are blocked or ligated. These procedures for both men and women can be reversed in some cases.

Answer 24

Sterilization

Question 25

____ of human ova and embryo transfer is the standard procedure used by laboratories throughout the world

Answer 25

In vitro fertilization [IVF]

Question 26

___ is a problem for 14% to 15% of couples. Male infertility may be a result of insufficient numbers of sperm and/or poor motility. Infertility in a woman may be due to a number of causes, including occluded uterine tubes [most commonly caused by pelvic inflammatory disease], hostile cervical mucus, immunity to spermatozoa, absence of ovulation, and others.

Answer 26

Infertility

Question 26

One percent to 2% of all pregnancies in the United States occur using _____

Answer 26

assisted reproductive technology [ART]

Question 27

____ is a drug used to increase FSH concentrations to stimulate ovulation. The drug is given early in the menstrual cycle to cause ovulation in women who do not ovulate or who ovulate irregularly

Answer 27

Clomiphene citrate [Clomid]

Question 28

Severe male infertility, in which the ejaculate contains very few live sperm [____] or even no live sperm [___], can be overcome using ___

Answer 28

oligozoospermia - azoospermia - ICSI

Question 29

Severe ____, in which the ejaculate contains very few live sperm [oligozoospermia] or even no live sperm [azoospermia], can be overcome using ICSI.

Answer 29

male infertility

Question 30

These cells, which become smaller with each cleavage division, are known as ____

Answer 30

blastomeres

Question 31

This process, ___, segregates inner cells, which communicate extensively by gap junctions, from outer cells

Answer 31

compaction

Question 32

Approximately 3 days after fertilization, cells of the compacted embryo divides again to form a 16-cell ___ (mulberry)

Answer 32

morula

Question 33

Gradually, the intercellular spaces become confluent, and finally, a single cavity, the ___, forms. At this time, the embryo is a ___

Answer 33

blastocele - blastocyst

Question 33

Cells of the inner cell mass, now called the ___, are at one pole, and those of the outer cell mass, or ____, flatten and form the epithelial wall of the blastocyst

Answer 33

embryoblast - trophoblast

Question 34

Inner cells of the morula constitute the ___, and surrounding cells compose the ____

Answer 34

inner cell mass - outer cell mass

Question 35

The inner cell mass gives rise to tissues of the ___, and the outer cell mass forms the ___, which later contributes to the ___

Answer 35

embryo proper - trophoblast - placenta

Question 36

ES cells may be obtained from embryos after ___, a process called ____. This approach has the disadvantage that the cells may cause immune rejection because they would not be genetically identical to their hosts

Answer 36

IVF - reproductive cloning

Question 36

____ are derived from the inner cell mass of the embryo. Because these cells are ___ and can form virtually any cell or tissue type, they have the potential for curing a variety of diseases, including diabetes, Alzheimer and Parkinson diseases, anemias, spinal cord injuries, and many others

Answer 36

Embryonic stem cells [ES cells] - pluripotent

Question 37

Under the influence of fibroblast growth factors (FGFs) at the early blastocyst stage, cells in the embryoblast differentiate into ___ and ____

Answer 37

epiblast - hypoblast cells

Question 37

In addition, some of the hypoblast cells are specified to form the ____, and these cells migrate to what will become the cranial end of the embryo

Answer 37

anterior visceral endoderm (AVE)

Question 38

New studies suggest that ____ on trophoblast cells and its ____ on the uterine epithelium mediate initial attachment of the blastocyst to the uterus

Answer 38

L—selectin - carbohydrate receptors

Question 39

Adult tissues contain stem cells that may also prove valuable in treating diseases. These cells are restricted in their ability to form different cell types and, therefore, are ___, not pluripotent, although scientists are finding methods to circumvent this disadvantage

Answer 39

multipotent

Question 40

The exact number of _____ formed is unknown because they are usually lost within 2 to 3 weeks of fertilization, before the woman realizes she is pregnant, and therefore, are not detected.

Answer 40

abnormal zygotes

Question 40

With the use of a combination of IVF and ___, molecular screening of embryos for genetic defects is being conducted.

Answer 40

polymerase chain reaction

Question 40

The wall of the uterus consists of three layers:

Answer 40

1. Endometrium or mucosa lining the inside wall 2. Myometrium, a thick layer of smooth muscle 3. Perimetrium, the peritoneal covering lining the outside wall

Question 41

Estimates indicate that as many as _____ and that half of these losses are a result of chromosomal abnormalities

Answer 41

50% of pregnancies end in spontaneous abortion

Question 42

As a result, three distinct layers can be recognized in the endometrium: a superficial____, an intermediate ___, and a thin___

Answer 42

compact layer - spongy layer - basal layer

Question 42

The results of fertilization are the following:

Answer 42

1. Restoration of the diploid number of chromosomes 2. Determination of chromosomal sex 3. Initiation of cleavage

Question 42

During this menstrual cycle, the uterine endometrium passes through three stages:

Answer 42

1. Follicular or proliferative phase 2. Secretory or progestational phase 3. Menstrual phase

Question 42

When the ____ begins, blood escapes from superficial arteries, and small pieces of stroma and glands break away. During the following 3 or 4 days, the compact and spongy layers are expelled from the uterus, and the basal layer is the only part of the endometrium that is retained

Answer 42

menstrual phase

Question 43

This layer, which is supplied by its own arteries, the ___, functions as the regenerative layer in the rebuilding of glands and arteries in the proliferative phase

Answer 43

basal arteries

Question 44

This layer, which is supplied by its own arteries, the basal arteries, functions as the regenerative layer in the rebuilding of glands and arteries in the ____

Answer 44

proliferative phase

Question 44

As soon as the spermatocyte has entered the oocyte: 1. The oocyte finishes its second meiotic division and forms the ____. 2. The zona pellucida becomes impenetrable to other spermatozoa. 3. The head of the sperm separates from the tail, swells, and forms the ____

Answer 44

female pronucleus - male pronucleus