Chapter 29 Flashcards
The _____ begins with fertilization and ends approximately 38 weeks later with birth
prenatal period
The prenatal period includes the ____, _____, and the _____.
pre-embryonic (germinal) period
embryonic period
fetal period
The ____ period is the first 2 weeks, fertilization to implantation in uterine wall.
pre-embryonic period
Fertilization —-> ____ —–> blastocyst
zygote
The ____ takes place during weeks 3-8, organ development
embryonic period
The _____ is the last 30 weeks, organ complexity increases
fetal period
____ is the process by which two gametes fuse to form a new diploid cell containing genes from both parents
fertilization (phase 1)
Fetilization takes place in the _____ or the uterine tube.
ampulla
Sperm undergo _____ upon entry into the female reproductive system.
capacitation
_____ is when glycoproteins and proteins removed from plasma membrane that covers acromosomal region
capacitation
During phase 1 of fertilization sperm penetrates the ____.
cornona radiata
During phase 1 of fertilization the oocyte releases _________ attracting sperm to its location
chemotaxic chemicals
Once sperm reach the oocyte they push through the corona radiata using _____.
their flagellum
During phase 2 of fertilization there is a release of digestive enzymes from acrosome needed to penetrate the zona pellucida called ______.
acrosome reaction
Once a sperm gets through the zona pellucida, it then _____ to prevent other sperm from entering
hardens
_____ is when an egg is fertilized with two or more sperm.
polyspermy
Polyspermy can be _____ because too many chromosomes.
fatal
Sperm undergoes acrosome reaction and penetrates ______ during phase 2 of fertilization.
zona pellucida
During phase 3 of fertilization sperm and oocyte ______ fuse, the sperm nucleus enters the cytosol of the secondary oocyte. The midpiece and _____ degenerate.
plasma membranes
flagellum
During the 3rd phase of fertilization the secondary oocyte completes the _____ division and forms an ovum
second meiotic
During the 3rd phase of the fertilization the sperm and ovum pronuclei then fuse forming a single diploid cell called a _____.
zygote
The zygote is a single _____.
diploid cell
A series of mitotic divisions resulting in an increase in cell number, but not an increase in the overall size of the structure is called ______.
cleavage
At the 16-cell stage (4 divisions) the zygote is called a _____ and enters the ______ of the uterus.
morula
lumen
Zona pelludica starts to degenerate allowing fluid to enter the morula forming a fluid filled cavity is the formation of the _____.
blastocyst
____ starts to degenerate allowing fluid to enter the morula forming a fluid filled cavity during blastocyst formation.
zona pelludica
a blastocyst and has two distinct components: ______ and _______.
trophoblast
embryoblast
The ____ is the outer ring of cells surrounding fluid filled cavity.
trophoblast
The ______ is the inner cell mass located within one side of the blastocyst
embryoblast
The process by which the blastocyst burrows into and embeds within the endometrium is called ____.
implantation
During implantation around day 7, trophoblast cells invade the _____ and then divide into two layers.
functional layer
The trophoblast cells divide into two layers, _________ and __________ after they invade the functional layer during implantation.
cytotrophoblast
syncytiotrophoblast
_____ is the inner cellular layer formed when the trophoblast cells divide during implantation.
cytotrophoblast
_____ is the outer, thick layer formed when the trophoblast cells invade the functional layer and divide. This is where the cells _____ into the functional layer.
syncytiotrophoblast
burrow
By day 9 of implantation the ____ has completely burrowed into the uterine wall.
blastocyst
_____ is produced by the syncytiotrophoblast
HCG
Human Chorionic Gonadotropin hormone
HCG is produced by the ______.
syncytiotrophoblast
HCG signals corpus luteum to continue secreting ________ to thicken and maintain uterine lining.
estrogen/progesterone
____ levels high enough detected in woman’s urine after second week of development.
HCG
HCG levels remain high for the first ____ months and then decline.
three
The _____ degenerates once HCG levels drop. At this point estrogen/progesterone is secreted by the ____.
corpus luteum
placenta
By day 8, embryoblast differentiates into two layers: _______ and _______.
hypoblast
epiblast
The ____ forms into the yolk sac.
hypoblast
The ____ forms into amnion.
epiblast
Hypoblast + epiblast =’s ________
bilaminar germinal disc
Bilaminar germinal disc and trophoblast produce ________.
extraembryonic membranes
The _____ protects the embryo.
extraembryonic membranes
The _____ assist in vital functions such as nutrition and gas exchange as well as removal and storage of _____.
extraembryonic membranes
waste materials.
The ____ is the first membrane to develop.
yolk sac
The _____ is an important site for early blood cell and blood vessel formation.
yolk sac
The _____ eventually encloses the entire embryo in a fluid-filled sac called the amniotic cavity.
amnion
The ____ is formed from both cytotrophoblast cells and syncytiotrophoblast
chorion
The ____ blend with functional layer of endometrium and eventually forms the placenta
chorion
The chorion blend with functional layer of endometrium and eventually forms the ____.
placenta
The function of the _____ is to exchange of nutrients, waste products, and respiratory gases between the maternal and fetal blood.
placenta
Transmission of maternal antibodies to the developing embryo or fetus occurs in the ____.
placenta
The _____ produces of estrogen and progesterone to maintain and build the uterine lining.
placenta
The placenta begins to form during the ____ of development.
2nd week
The chorion forms ____ portion and ____ layer of uterus forms maternal portion.
fetal
functional
Early organism connected to the placenta via the ______, which eventually forms the umbilical cord
connecting stalk
____ form from the chorion.
chorionic villi
The chorion villi contain branches of _____.
umbillical vessels
The chorionic villi are surrounded by ______ which contains maternal blood.
endometerium
Fetal blood and maternal blood ___, but bloodstreams so are so close they allow for the exchanges of gases and nutrients.
do not mix unless something goes wrong
Alcohol, drugs, ___, bacteria, and ____ from smoking can pass through placental barrier as well.
viruses
toxins
The ___ period takes place from weeks 3 thru 8.
embryonic
____ is the establishment of primary germ layers.
gastrulation
_____ is the formation of specific tissues and organs from the primary germ layers.
organogenesis
The _____ period involves gastrulation and organogenesis
embryonic
By week ___ the embryo has a beating heart.
week 4
By week ____ the main organ systems have been established.
8
____ is the process by which the cells of the epiblast migrate and form the three primary germ layers.
gastrulation
The three primary germ layers
ectoderm
mesoderm
endoderm
The formation of germ layers forms an ____.
embryo
During gastrulation, the cells from epiblast migrate through ______ to the area between the epiblast and hypoblast forming the ______
primitive streak
endoderm
During gastrulation more epiblast cells migrate and form the ____.
mesoderm
Remaining cells of the epiblast form the _______.
ectoderm
An ____ is a flattened, disc-shaped structure.
embryonic disc
In the late 3rd to 4th weeks, ____ transforms shape.
embryonic disc
Certain regions of the embryo grow ____ than others causing folding.
faster
The two types of folding caused by faster growth in regions of the embryo are ______ and ______.
cephalocaudal
transverse
Folding that occurs in the cephalic and caudal regions of the embryo is ____ folding.
cephalocaudal
Amnion grows very quickly but ___ does not grow at all during cephalocaudal folding.
yolk sac
____ folding forms the future head and buttocks region.
cephalocaudal
Left and right sides of the embryo curve and migrate toward the midline during ______
transverse folding
During transverse folding sides fuse in midline to create a ______ embryo creating the trunk/torso region.
cylindrical
During transverse folding the ____ is pinched off from most of the endoderm except one small region called the ____.
yolk sac
vitelline duct
_____ now solely along entire exterior embryo and endoderm confined to the internal region during transverse folding.
Ectoderm
____ forms nervous tissue and sensory organs.
ectoderm
_____ forms the epidermis and it’s derivatives. What are examples?
Ectoderm
hair, nails, sweat glands, mammary glands
____ forms the enamel of the teeth.
ectoderm
______ forms muscle and connective tissues.
mesoderm
______ forms the dermis.
mesoderm
_____ forms the pituitary gland.
ectoderm
_____ forms the lens of the eye.
ectoderm
_____ forms the adrenal medulla.
ectoderm
_____ forms kidneys.
mesoderm
_____ forms ureters.
mesoderm
______ forms reproductive system.
mesoderm
_____ forms spleen.
mesoderm
