Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

embryology > Chapter 3 > Flashcards

Chapter 3 Flashcards

1
Q

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

A

sexual cycles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

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 ____

A

gonadotropins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

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

A

Gonadotropin-releasing hormone (GnRH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

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

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

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

A

corpus atreticum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

FSH also stimulates the maturation of ___ cells surrounding the oocyte

A

follicular (granulosa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

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

A

stigma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

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

A

ovulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

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

A

corona radiata

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

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

A

lutein cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

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 ___

A

progesterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

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

A

corpus luteum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

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

A

progestational or secretory stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

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

A

luteolysis - corpus albicans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

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

A

human chorionic gonadotropin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

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

A

corpus luteum of pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

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

A

ampullary region of the uterine tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

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

A

corpus luteum graviditatis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

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

A

Capacitation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

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

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

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

A

acrosome reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The phases of fertilization include the following:

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

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

A

cortical granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

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

A

zona reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

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

A

male pronucleus

20
Q

____ are another commonly used form of contraception.

A

Hormonal methods

21
Q

___ 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

A

Barrier methods

22
Q

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.

A

male “pill”

22
Q

____ 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]

A

Emergency contraceptive pills [ECPs]

23
Q

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

A

intrauterine device [IUD]

24
Q

____ 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.

A

Sterilization

25
Q

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

A

In vitro fertilization [IVF]

26
Q

___ 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.

A

Infertility

26
Q

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

A

assisted reproductive technology [ART]

27
Q

____ 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

A

Clomiphene citrate [Clomid]

28
Q

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

A

oligozoospermia - azoospermia - ICSI

29
Q

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

A

male infertility

30
Q

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

A

blastomeres

31
Q

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

A

compaction

32
Q

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

A

morula

33
Q

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

A

blastocele - blastocyst

33
Q

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

A

embryoblast - trophoblast

34
Q

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

A

inner cell mass - outer cell mass

35
Q

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

A

embryo proper - trophoblast - placenta

36
Q

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

A

IVF - reproductive cloning

36
Q

____ 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

A

Embryonic stem cells [ES cells] - pluripotent

37
Q

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

A

epiblast - hypoblast cells

37
Q

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

A

anterior visceral endoderm (AVE)

38
Q

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

A

L—selectin - carbohydrate receptors

39
Q

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

A

multipotent

40
Q

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.

A

abnormal zygotes

40
Q

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

A

polymerase chain reaction

40
Q

The wall of the uterus consists of three layers:

A
  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
41
Q

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

A

50% of pregnancies end in spontaneous
abortion

42
Q

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

A

compact layer - spongy layer - basal layer

42
Q

The results of fertilization are the following:

A
  1. Restoration of the diploid number of
    chromosomes
  2. Determination of chromosomal sex
  3. Initiation of cleavage
42
Q

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

A
  1. Follicular or proliferative phase
  2. Secretory or progestational phase
  3. Menstrual phase
42
Q

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

A

menstrual phase

43
Q

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

A

basal arteries

44
Q

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 ____

A

proliferative phase

44
Q

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 ____

A

female pronucleus - male pronucleus

embryology (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions