Embryo development: cleavage to organogenesis Flashcards by Geno Sadaya

The extraembryonic mesoderm are formed from:

a. Primary yolk sac
b. Secondary yolk sac
c. Amniotic cavity
d. Chorionic cavity

How well did you know this?

Not at all

Perfectly

Localized thickening of hypoblast

a. Prechordal plate
b. Cloacal plate
c. Oropharyngeal membrane
d. Bucopharyngeal membrane

How well did you know this?

Not at all

Perfectly

Epiblast is associated with

a. Primary yolk sac
b. Secondary yolk sac
c. Amniotic cavity
d. Chorionic cavity

How well did you know this?

Not at all

Perfectly

Process by which epiblast gives rise to 3 germ layers

a. Gastrulation
b. Neurulation
c. Involution

How well did you know this?

Not at all

Perfectly

Allantois is a diverticulum of the

a. Primary yolk sac
b. Definitive yolk sac
c. Amniotic Cavity
d. Chorionic Cavity

How well did you know this?

Not at all

Perfectly

Chorionic villi associated with decidua that are compressed:

a. Decidua basalis
b. Decidua capsularis
c. Decidua parietalis
d. Decidua vera

How well did you know this?

Not at all

Perfectly

Structure in placenta membrane that disappears at term

a. Syncytiotrophoblast
b. Mononucleated layer of cells
c. Villi
d. Chorionic plate

How well did you know this?

Not at all

Perfectly

Primary yolk sac develops from the

a. Extracoelomic space
b. Amniotic cavity
c. Chorionic Cavity
d. Blastocoele

How well did you know this?

Not at all

Perfectly

Somites form from the:

a. Paraxial mesoderm
b. Intermediate mesoderm
c. Lateral plate mesoderm
d. AOTA

How well did you know this?

Not at all

Perfectly

Which is the origin of the three germ layers?

a. Epiblast
b. Hypoblast
c. Yolk sac
d. Trophoblast

How well did you know this?

Not at all

Perfectly

Primordium of intervillous space

a. Lacunae of cytotrophoblast
b. Lacunae of syncytiotrophoblast
c. Epiblast
d. Hypoblast

How well did you know this?

Not at all

Perfectly

Ultrasound can detect a mass at the coccygeal area of the fetus. What is the probable origin?

a. Allantois
b. Ileal diverticulum
c. Primitive Streak

How well did you know this?

Not at all

Perfectly

What lines the extraembryonic coelom?

a. Amniotic membrane
b. Heusser’s
c. Exocoelomic membrane
d. Chorionic Membrane

How well did you know this?

Not at all

Perfectly

Between which two membranes does the extraembryonic mesoderml lie?

a. Epiblast and Hypoblast
b. Cytotrophoblast and syncitiotrophoblast
c. Exocoelomic and syncitiotrophoblast
d. Cytotrophoblast and chorionic membrane

How well did you know this?

Not at all

Perfectly

Characteristics or one-week old blastocyst

a. Has a single layer of trophoblast
b. Developed amniotic cavity at embryonic pole
c. Attached to the uterine endometrium
d. Surrounded by a degenerating zona pellucida

How well did you know this?

Not at all

Perfectly

Early Stage of Cleavage are characterized by

a. Increase in number of cells inside the zona pellucida
b. Increase in size of cells in the zona
pellucida
c. Increase in size and number of cells in the zona pellucida
d. Formation of zona pellucida

How well did you know this?

Not at all

Perfectly

Development of primary oocytes occur

a. Before birth
b. At birth
c. During puberty
d. During pregnancy

How well did you know this?

Not at all

Perfectly

Forerunner of gut?
A. Chorionic cavity
B. Amniotic Cavity
C. Yolk Sac
D. Allantois

How well did you know this?

Not at all

Perfectly

Which structure forms the urachus in the fetus?

Allantois

How well did you know this?

Not at all

Perfectly

Endometrium of a pregnant woman is called:
A. Decidua
B. Placenta
C. Myometrium
D. Penis

How well did you know this?

Not at all

Perfectly

Where is the cardiogenic area?

Superior to the prechordal plate

How well did you know this?

Not at all

Perfectly

The longitudinal fold of the embryo along the median plane includes the following EXCEPT:

A. Allantois is incorporated into the embryo and the umbilical cord
B. Formation of ventral body wall
C. Formation of head and tail fold
D. The primordial heart moves ventral to the prechordal plate

How well did you know this?

Not at all

Perfectly

Which forms the primitive groove?

A. Epiblast
B. Hypoblast
C. Somatic mesoderm
D. Splanchnic mesoderm

How well did you know this?

Not at all

Perfectly

Gives rise to the axial skeleton and its corresponding musculature

A. Somites
B. Notochord
C. Cloacal membrane
D. Endoderm

How well did you know this?

Not at all

Perfectly

What is the forerunner of the primary yolk sac?

Blastocoel

The villi adjacent to the decidua basalis are called?

Chorion frondosum

Which of the following is involved in the production of hormones in the luteal phase? A. oocyte B.placental cell C. theca-lutein cells D.ovarian follicular cells

When a zygote divides to have 2-8 cells what is it called?

Blastomere

When a zygote divides to have 16 cells what is it called?

Morula

A blastocyst is characterized by which structure?

Blastocoel

The outer cell layer of a blastocyst is called what?

Trophoblast

The cell layer inside the trophoblast of a blastocyst is called what?

Inner cells mass

What is the process in which a blastocyst loses its zona pellucida?

Hatching

What is the process by which a zygote becomes a blastomere?

Cleavage

Which structure is lost during hatching?

Zona pellucida

The trophoblast gives rise to which two layers of cells in the second week of gestation?

Syncytiotrophoblast and cytotrophoblast

The embryoblast gives rise to which two layers of cells in the second week of gestation?

Epiblast and hypoblast

Which cell layer of the second week of gestation is multinucleated and has no discernible cell boundaries?

Syncytiotrophoblast

Which cell layer is underneath the syncytiotrophoblast?

Cytotrophoblast

Which cell layer from the embryoblast is columnar?

Epiblast

Which cell layer from the embryoblast is cuboidal?

Hypoblast

Syncytiotrophoblast and cytotrophoblast derive from which layer?

Trophoblast

The blastocoel gives rise to which structure on the second week of gestation?

Primary yolk sac/ Heuser's cavity/ extracoelomic cavity

The hypoblast and epiblast derive from which cells?

Embryoblast

The membrane that lines the primary yolk sac is from which cells?

Hypoblast

The amniotic cavity is associated with: blastocoel, primary yolk sac or secondary yolk sac?

Primary yolk sac and secondary yolk sac

The primary yolk sac is derived from which structure?

Blastocoel

Which cells line the amniotic cavity?

Amnioblasts

Amnioblasts are from which cell layer?

Epiblast

The extraembryonic mesoderm lines which cavity?

Primary yolk sac/ Heuser's cavity/ extracoelomic cavity

The extraembryonic mesoderm comes from which cell layer?

Hypoblast

The spaces that appear in the syncytiotrophoblast during the second week of gestation are what?

Lacunae

What does the trophoblastic lacuna contain?

Maternal blood

The primary villi is made up of which cells?

Cytotorophoblast

The chorionic caviry is associated with which cavities?

Amniotic cavity, secondary yolk sac

The connective stalk is made up of which layer?

Extraembyonic mesoderm

Which membrane lines the secondary yolk sac?

Extraembryonic mesoderm

The primary yolks sac gives rise to which structure?

Nothing. It regresses during the second week of gestation.

The connecting stalk gives rise to which structure when blood vessels develop?

Umbilical cord

What is the process wherein the bilaminar disc of the embryo develops into a trilaminar disc?

Gastrulation

What are the three layers of the trilaminar disc?

Endoderm, mesoderm, ectoderm

Which week does gastrulation occur?

Third week

Gastrulation begins with the formation of which structure on the surface of the epiblast?

Primitive streak

The primitive streak begins on which pole of the embryo?

Caudal pole

Which cell layer gives rise to the three germ layers?

Epiblast

Which structure marks the cephalic end of the bilaminar layer?

Prechordal plate

The oropharyngeal layer is from which precursor?

Hypoblast

The primitive streak moves to which direction?

Cephalic

The hypoblast is replaced by which cells during gastrulation?

Endoderm

The formation of the notochord begins from which pole?

Cephalic end

The posterior wall of the secondary yolk sac becomes which structure?

Allantois

What purpose does the allantois serve in the embryo?

A reservoir for excretion products | of the renal system

What is the difference between primary villi and secondary villi?

Secondary villi have a extraembryonic mesoderm inner core.

What is the difference between secondary villi and tertiary villi?

Tertiary villi have blood vessels

Villi that extend from the chronic plate to the decidua basalis are called what?

Stem or anchoring villi

Villi that branch from the side of stem villi are called what?

Free (terminal) villi

When does organogenesis occur?

Third to eight weeks of gestation

At the beginning of the third week of development, the ectodermal germ layer is broader caudally or cephalic?

Cephalic

What is the function of the primary streak?

Determines body axis

The primitive streak moves rostrally and stops at which point?

The prechordal plate

What is neurulation?

The process by which the neural plate forms the neural tube.

``` What is formed by the extraembryonic mesoderm and trophoblasts? A. Amniotic membrane B. Chorionic membrane C. Heissner’s membrane D. Exocoelomic membrane ```

Formation of the neural tube is dependent on the development of which structure? A. Primitive streak B. Germ layers C. Notochord D. Allantois

What embryonic structure contributes to the formation of the head and neck? A. Mesonephric ridge B. Auricular hillock C. Pharyngeal arches D. Somites

The cardiogenic area is located in which position relative to the prechordal plate? A. Superior B. Inferior C. Dorsal D. Ventral

All primary oocytes are formed when? A. Before birth B. At birth C. Puberty D. AOTA

What structure is the primordium of the primitive gut? A. Primary yolk sac B. Secondary yolk sac C. Chorion

``` The term placental villi which lie free in the intervillous space is called? A. Terminal villi B. Stem villi C. Anchoring villi D. Primary villi ```

``` Embryological structure associated with urinary bladder formation A. Notochord B. Secondary yolk sac C. Primitive streak D. Allantois ```

Pregnancy hormone A. HCG B. hPL C. LDL D.GnRH

The hypoblast forms the roof of the a. amniotic cavity b. yolk sac c. chorionic cavity d. blastocystic cavity

Spaces within the extraembryonic mesoderm a. amniotic sac b. yolk sac c. chorionic cavity d. blastocystic cavity

Primary role of deciduas a. produces progesterone b. provides immunological protection for conceptus c. produces HCG d. provides nutrition for the embryo

The embryoblast is between the yolk sac and the a. chorionic cavity b. amniotic cavity c. extraembryonic cavity d. blastocystic cavity

First sign of gastrulation a. appearance of primitive streak b. formation of notochord c. development of 3 germ layers d. development of neural tube

At what embryonic stage can you first appreciate the presence of the notochord?

Neurula

What week of the embryonic life do pharyngeal arches appear? a. 4th wk b. 5th wk c. 6th wk d. 7th wk

Failure of the progression of lateral body folding will result to the following anomalies except a. gastroschisis b. omphalocoele c. cleft sternum d. bladder exstrophy

Embryonic structure that persists as the nucleus pulposus of the intervertebral disc a. primitive streak b. notochord c. somite d. . pharyngeal arch

Villi that extends from the decidua basalis to chorion: a) Anchoring villi b) Terminal villi c) Stem villi d) Branch villi

Villi adjacent to the decidua basalis contributing to the formation of placenta: a) Chorion frondosum b) Chorion laeve c) Decidual plate d) Chorionic villi

Which of the following disappears as the placenta becomes older? a) Endothelium of fetal capillaries b) Connective tissue of villi c) Syncytiotrophoblast d) Cytotrophoblast

38. Exchange of materials between mother and fetus by? a) Communicating lymphatic channels between mother and fetus b) Diffusion from maternal blood sinus to fetal blood across syncytial and endothelial membrane c) Opening between amnion and chorion d) Anastomoses between maternal and fetal blood vessel

What type of villi is devoid of blood vessels and connecting tissue? a) Primary villi b) Secondary villi c) Tertiary villi d) Anchoring villi

The following is/are true of the function of the placenta: a) Synthesizes steroid and protein hormones but not phospholipid-derived mediators which orchestrate maternal adaptations to pregnancy and regulates fetal and placental function and maturation b) Serves as a communication interface between maternal and fetal compartments and responds to changes in chemical, endocrine, and immune signals derived from both compartments c) Serves as a barrier by preventing the passage of waste and metabolic end-products towards the fetal side d) AOTA

Human chorionic gonadotropin: a) Presence of sialic acid at its terminal end prevents it from catabolic degradation b) Its alpha-subunit is structurally related to TSH, FSH and LH c) At less than 5 weeks age of gestation, produced in syncytiotrophoblast and cytotrophoblast d) AOTA

A 25 y.o. pregnant woman with amenorrhea of 6 weeks is diagnosed with an ovarian cust of 8 cm. When is the best time to surgically removethe cyst? A. immediately B. 8-10 weeks AOG C. after 24 weeks AOG D. any of the above