High Yield Embryology

Question 1

Teratogen

Answer 1

Substance affecting migration, proliferation, or interaction of cells
Causes congenital anomalies

Question 2

Capacitation

Answer 2

Pruning of the sperm glycocalyx; permits the sperm-oocyte interaction

Question 3

Ectopic pregnancy

Answer 3

Implantation that occurs outside of the uterine cavity; can occur in uterine tubes or in the pelvic cavity

Question 4

Placenta Previa

Answer 4

Implantation occurs near the cervix

Provides high risk of bleeding

Question 5

Placental Abruption

Answer 5

Placenta becomes attached

Question 6

Placenta accreta

Answer 6

Abnormal adherence of the chorionic villi to the myometrium

Question 7

Placenta percreta

Answer 7

Villi penetrate the full thickness of the myometrium

Question 8

Hydatidiform moles

Answer 8

Result when there is no embryo or embryo dies and chorionic villi fail to vascularize
“Uterine enlargements greater than expected for gestational age”

Question 9

What are long-term complications of hydatidiform moles?

Answer 9

Give rise to choriocarcinomas or persistent trophoblastic disease

Question 10

Complete mole

Answer 10

Fertilization of empty oocyte (contains only paternal chromosomes)
Produces high levels of hCG

Question 11

Partial moles

Answer 11

Derive from a poorly developed embryo

Always triploid and produce hCG

Question 12

Dizygotic (fraternal) twins

Answer 12

Arises from multiple ovulations (high levels of FSH)

Question 13

Monozygotic (identical) twins

Answer 13

Arise from splitting of single zygote

Question 14

Human chorionic gonadotrophin (hCG)

Answer 14

Secreted by syncytiotrophoblast

Question 15

Progesterone

Answer 15

Secreted by corpus luteum for five months, then by placenta

Contraceptive “pill” and RU-486 are anti-progesterones

Question 16

Gastrulation

Answer 16

Process where the epiblast gives rise to mesoderm, endoderm, and ectoderm

Question 17

Notochord

Answer 17

Derives from both endoderm and mesoderm; forms the nucleus pulposus

Question 18

Sirenomelia

Answer 18

Caudal dysgensis from inadequate mesoderm

Lower limb defects

Question 19

Sacrococcygeal teratoma

Answer 19

Persistence of primitive streak, forms multi-tissue tumor

Question 20

Alpha-fetoprotein

Answer 20

Liver glycoprotein

Leaks into amniotic fluid with neural tube or ventral wall defects

Question 21

Spina bifida occulta

Answer 21

Incomplete neural arch, patch of hair over defect

Question 22

Poland anomaly

Answer 22

Congenital absence of the pectoralis major

Question 23

Congenital torticollis

Answer 23

Contracture/shortening of the sternocleidomastoid

Question 24

Amelia

Answer 24

absence of a limb

Question 25

Meromelia

Answer 25

Absence of part of a limb

Question 26

Congenital clubfoot

Answer 26

Any defect involving the talus

Question 27

What does splanchnic mesoderm form?

Answer 27

Primitive heart tube | Beats on day 22

Question 28

Pleuropericardial membranes

Answer 28

Form pericardium and pleura (somatic parts)

Question 29

Tetrology of Fallot

Answer 29

A combo of 4 heart defects - pulmonary stenosis - right ventricular hypertrophy - over-riding aorta - ventricular septal defect

Question 30

Dextrocardia

Answer 30

Right-sided heart

Question 31

Undivided truncus arteriosus

Answer 31

Neural crest defect where the bulbar regions fail to form

Question 32

Patent ductus arteriosus

Answer 32

Common defect associated with rubella and pregnancies occurring in high altitudes, more common in females

Question 33

Atrial septal defect

Answer 33

Patent foramen ovale common | Can involve defect in septum primum or septum secundum

Question 34

Ventricular septal defect

Answer 34

Common | Involves membranous part of the interventricular septum

Question 35

Transposition of the great vessels

Answer 35

Most common cause of cyanosis in newborn

Question 36

Vitelline vein

Answer 36

Left disappears, right forms portal system

Question 37

Umbilical vein

Answer 37

Right disappears | Left drains placenta - becomes ligamentum teres hepatis

Question 38

Cardinal vein

Answer 38

Subcardinal - drains kidneys Sacrocardinal - common iliac Supracardinal - drains body wall (azygos veins)

Question 39

Ductus venosus

Answer 39

Between left umbilical and right vitelline veins | Forms ligamentum venosum

Question 40

Early development of lung

Answer 40

Begins in 4th week, derived from gut tube | Lungs become viable during the 24th gestational week due to secretion of surfactant

Question 41

When does formation of most alveoli occur?

Answer 41

Between birth and the 8th year

Question 42

Tracheoesophageal fistula

Answer 42

Abnormal connection between esophagus and airway | Usually involves a proximal esophagus that ends in a blind pouch and a distal esophagus that connects to the trachea

Question 43

VACTERL association

Answer 43

``` Combination of defects that arise from exposure to high levels of estrogens/progesterones during the embryonic period (weeks 3-9) Vertebral defects Anal atresia Cardiac defects Trachioesophageal fistula Renal anomalies Limb abnormalities ```