Chapter 23 Pregnancy
How many sperm cells fertilize an oocyte?
1
The yolk sac is indicated by.... 3 fill in the blanks
1. B 2. A 3. C
Put the steps that occur during fertilization in the correct order, starting at the top with the first event to occur after the sperm reaches the secondary oocyte in the uterine tube.
1. sperm cell penetrates 2. the acrosome 3. the sperm cell pentrates the zona p 4. the sperm cell membrane 5. vesicles
Once semen is ejaculated into the female reproductive system, the sperm cells begin their journey toward the secondary oocyte. Place the structures in the order through which the sperm cells pass on their way to the secondary oocyte, with the first place sperm enter at the top.
1. vagina 2. cervix 3. uterus 4. uterine tube
Sperm cells are best able to fertilize an oocyte ______ hours after ejaculation.
24-48 hours
How many chromosomes are found in a zygote?
46
Pair the arrow with the structure.
A - Cervix B- uterine wall C- Vagina
Match the arrow with the structure.
A -umbilical cord B - maternal blood vessels C- chorion D- endometrium
Pregnancy can best be described as the condition in which ______.
A woman is carrying an offspring in her uterus.
Match each arrow with the correct structure.
A-endometrium B- blastocyst C - zygote D - morula
How do the uterine tubes function in reproduction?
Cells lining the uterine tubes have cilia that move the developing embryo toward the uterus.
Match each word element to its definition.
Chorio - skin allant - sausage morul - mulberry mes - middle lacun - pool
Describe the interaction of the fetal and maternal blood systems.
Fetal and maternal blood are separated by a placental membrane.
describe the interaction of the fetal and maternal blood systems.
Fetal and maternal blood are separated by a placental membrane.
For each process, indicate the correct arrow.
Implantation - Arrow C Ovulation - Arrow A Cleavage - Arrow B
What happens to a fetus that was conceived by two sperm cells penetrating one secondary oocyte?
It would have gross abnormalities and would not survive.
Which four of the following occur during fertilization?
Pronuclei unite to complete fertilization. The tiny second polar body is expelled from the fertilized egg. The sperm cell nucleus enters the oocyte and swells while the cytoplasm of the secondary oocyte divides unequally. Meiosis is completed.
How does the blastocyst become embedded in the uterine lining?
The blastocyst produces enzymes that digest the uterine lining.
Describe the cells of a blastocyst, prior to implantation.
The cells are pluripotent.
What is amniotic fluid?
The fluid surrounding the embryo/foetus that protects the unborn baby
What is the amniochorionic membrane?
The membrane formed by the fusion of the chorion and amnion
Describe the prenatal period.
The prenatal period is from fertilization to birth.
How is a zygote formed?
The zygote is formed when the pronuclei of the sperm and secondary oocyte unite.
What would happen if more than one sperm cell fertilized a single oocyte?
The zygote would have too many chromosomes.
During development, the amniotic cavity enlarges to the point that the amnion presses against and fuses with the chorion. This results in the formation of the ______.
amniochorionic membrane
The ______ is a membrane enclosing the fluid-filled space surrounding the developing embryo.
amnion
The amniotic cavity is the space between the ______.
amnion and the embryonic disc
The membrane enclosing the fluid-filled space that surrounds the embryo after the second week of prenatal development is called the
amnion or amniotic
In the uterus, the fetus is surrounded by a fluid called ______.
amnionic fluid
What is the narrow space between the embryonic disc and amnion called?
amniotic cavity
What cushions the embryo and helps maintain embryonic body temperature?
amniotic fluid
What is the foramen ovale?
an opening in the interatrial septum that blood flows through
A developing embryo that consists of a hollow ball of cells is referred to as a(n) .
blastocyst
At about seven days after fertilization, the attaches to the lining of the uterus.
blastocyst
The developing embryo goes through a stage in which it is a hollow ball of cells. This hollow ball of cells is called a(n) ______
blastocyst
The extraembryonic membrane that forms the placenta is the .
chorion
The placenta arises from which extraembryonic membrane?
chorion
What is the name of the finger-like outgrowths of the chorion that grow into the endometrium?
chronic villi
The term that refers to the cell divisions that occur in the first three days after fertilization is .
cleavage
What is another term for the cell divisions that occur during the earliest stages of prenatal development?
cleavage
What is another term for the cell divisions that occur during the earliest stages of prenatal development
clevage
Cells in the uterine tube nourish and assist in moving the developing ______ toward the uterus.
clevage embryo
the umbilical cord arises from which structure?
connecting stalk
Enzymes produced by the blastocyst allow it to ______.
digest part of the uterine lining
During fetal development, blood from the umbilical cord flows directly into the vena cava bypassing the liver via a vessel called the ______.
ductus venosus
3 primary germ layers
ectoderm, mesoderm, endoderm
the three primary germ layers are
ectoderm, mesoderm, endoderm
The inner cell mass develops into which prenatal structure?
embryo proper
when does the fetal stage begin?
end of week 8
List three functions of the placenta.
exchange gases and nutrients between the maternal blood and embryonic blood produce hormones attach embryo to uterine wall
True or false: Although slightly different in composition, fetal hemoglobin and adult hemoglobin have the same affinity for oxygen.
false
True or false: During fertilization, the entire sperm cell enters and combines with the secondary oocyte to form the zygote.
false
True or false: Fetal and maternal blood freely mix in the chorionic cavity.
false
The process that involves the union of an oocyte and a sperm cell is called .
fertilization
Which form of hemoglobin has the greater affinity for oxygen?
fetal hemoglobin
A woman shows up for her 12-week check up. At this stage her offspring is considered a(n) ______.
fetus
What is the role of the primary germ layers?
five rise to all organs (give)
Blood from the right atrium of the fetal heart bypasses the lungs and flows directly into the left atrium through the ______.
foramen ovale
What occurs during gastrulation
formation of 3 germ layers
What is a function of the yolk sac?
forms blood cells for the embryo
During which stage of development do the primary germ layers form?
gastrula
The process of ______ involves the movement of embryonic cells to form a mesoderm between the ectoderm and endoderm layers of cells.
gastrulation
The hormone produced by trophoblast cells that maintains the corpus luteum during the early stages of pregnancy is ______.
hcg
Which part of a sperm cell enters the secondary oocyte during fertilization?
head
Removing the layers that surround the oocyte is due to the action of ______ sperm, but ______ sperm will fertilize the oocyte.
hundreds of; one
The process by which the blastocyst attaches to the uterine endometrium is called ______.
implantation
The process of embedding a blastocyst into the endometrium is called .
implantation
What usually occurs about seven days after fertilization?
implantation
A gastrula is the stage of development ______.
in which the three germ layers form
Which structure becomes the embryo proper?
inner cell mass
Muscular contractions force the fetus through the birth canal during the process called
labor
The middle germ layer of the embryo is the ______, while the outermost extraembryonic membrane is the ______
mesoderm; chorion
Which stage is indicated by the pointer? (One big circle image)
morula
Nutrients and wastes are exchanged between the embryo and maternal blood through the structure called the
placenta
The ______ is a vascular tissue produced by embryonic and maternal tissues that attaches the embryo to the uterine wall. Multiple choice question.
placenta
What is the name of the vascular structure that nourishes and connects the developing embryo to the uterine wall?
placenta
The condition in which a female is carrying an offspring in her uterus is called .
pregnancy
The presence of a developing offspring in the uterus is called .
pregnancy
The time period between fertilization and birth is called the period.
prental
What is the function of hCG (human chorionic gonadotropin)?
prevents the corpus luteum from degenerating
The hormone that is primarily responsible for the development of alveolar glands in breast tissue during pregnancy is .
progesterone
List three functions of the amniotic fluid.
protects embryo from jarring impacts prevents compression of embryo helps maintain embryonic body temperature
The trophoblast is ______.
the outer layer of cells of the blastocyst that develops into the placenta
Which of the following gives rise to the internal organs?
the primary germ layers
What is the outer layer of cells of a blastocyst called?
trophoblast
True or false: Cells of the early blastocyst (before implantation) are pluripotent.
true
Which structure is indicated at the tip of the pointer?
two-cell stage
Which structure suspends the embryo in the amniotic cavity?
umbilical cord
Which of these vessels carries well-oxygenated blood?
umbilical vein
What is fertilization?
union of a sperm and a secondary oocyte
What is the path of sperm cells, from ejaculation to the location of the secondary oocyte?
vagina → cervix → uterus → uterine tube
Within the umbilical cord, the vessel that carries oxygen-rich blood from the placenta to the fetus is the umbilical .
vein
The finger-like branches of the chorion that extend into the maternal endometrium are called chorionic .
villi
The structure that forms during the second week of development and functions to produce blood cells and precursors to the sex cells is the ____ _____
yolk sac
A single-celled, fertilized egg is known as a(n) .
zygote
Once fertilization is complete, the first cell of the future offspring has 46 chromosomes and is called a(n) .
zygote
To complete fertilization, the union of a sperm pronucleus with the pronucleus from a secondary oocyte forms the ______.
zygote
When the pronuclei of a sperm cell and a secondary oocyte join, a(n) is formed.
zygote