Embryology - Fertilization To Week 10

Front 1

Sonic hedgehog gene - function

Back 1

CNS development, patterning along anterior-posterior axis

Front 2

Mutation in sonic hedgehog

Back 2

Holoprosencephaly (failure of cerebral hemispheres to separate)

Front 3

Wnt-7 gene - function

Back 3

Organization along dorsal-ventral axis

Front 4

FGF gene - function

Back 4

Stimulates mitosis of underlying mesoderm --> limb lengthening

Front 5

Homeobox (Hox) genes - function

Back 5

Segmental organization of embryo

Front 6

Secondary oocyte stuck in which phase of oogenesis?

Back 6

Metaphase II (at ovulation)

Front 7

Primary oocytes stuck in which phase of oogenesis?

Back 7

Prophase I (before puberty)

Front 8

hCG production begins at which week?

Back 8

Week 1

Front 9

Implantation of blastocyst occurs on which day?

Back 9

Day 6

Front 10

Embryonic structures by Week 2

Back 10

Epiblast (all of embryo derived from this) + hypoblast

Front 11

Embryonic structures by Week 3

Back 11

Gastrulation: Ectoderm, Mesoderm, Endoderm
Primitive streak, notochord, neural plate

Front 12

Processes occurring Week 3 - 8

Back 12

Neural tube formation
Organogenesis
Susceptibility to teratogens at highest point

Front 13

Embryonic structures by Week 4

Back 13

Neural tube formed
Heartbeat appears
4 limb buds

Front 14

Characteristic of Week 8

Back 14

Start of fetal period: fetus looks like baby, begins to move

Front 15

Fetal characteristics at Week 10

Back 15

Genitalia differentiate between male/female

Front 16

Ectoderm - 3 structures

Back 16

Neural crest
Neuroectoderm
Surface ectoderm

Front 17

Surface ectoderm derivatives

Back 17

Epidermis + sweat glands
Parotid, salivary glands
Adenohypophysis
Epithelial lining of head cavities (mouth, ear, nose)

Front 18

Neuroectoderm derivatives

Back 18

CNS cells (brain + spinal cord)
Retina, optic nerve

Front 19

Neural crest derivatives

Back 19

PSN cells
Melanocytes
Adrenal medulla chromaffin cells
Thyroid parafollicular cells
Pia and arachnoid mater
Skull bones

Front 20

Mesoderm derivatives

Back 20

Muscle, CT
Serous lining of cavities (eg. peritoneum)
CVS structures, blood, lymphatics
Urethra, vagina, testis, ovary
Kidneys, spleen

Front 21

Endoderm derivatives

Back 21

Epithelial lining of gut tube
Gut tube derivatives: lungs, liver, gallbladder, pancraes, thymus, parathyroid, thyroid follicles

Front 22

Agenesis - definition

Back 22

Absent organ due to lack of primordial cells

Front 23

Aplasia - definition

Back 23

Absent organ, but primordial cells absent

Front 24

Deformation - definition

Back 24

Extrinsic disruption, after embryonic period (week 3-8)

Front 25

Hypoplasia - definition

Back 25

Incomplete organ development, primordial cells present

Front 26

Malformation - definition

Back 26

Intrinsic disruption, occurs during embryonic period (week 3-8)

Front 27

ACE inhibitor - teratogenic effect

Back 27

Renal damage

Front 28

Alkylating agents - teratogenic effect

Back 28

Absence of digits

Front 29

Amionglycoside - teratogenic effect

Back 29

CN VIII toxicity

Front 30

Diethylstilbestrol - teratogenic effect

Back 30

Vaginal clear cell adenocarcinoma
Congential Mullerian anomalies

Front 31

Lithium - teratogenic effect

Back 31

Ebstein's anomaly (atrialized R. ventricle)

Front 32

Phenytoin - teratogenic effect

Back 32

*Fetal hydantoin syndrome*: microcephaly, craniofacial anomalies, hypoplastic nails & distal phalanges, cardiac defects, IUGR, mental retardation

Front 33

Carbamazepine - teratogenic effect

Back 33

Neural tube defects, craniofacial defects, fingernail hypoplasia, IUGR

Front 34

Tetracyclines - teratogenic effect

Back 34

Discoloured teeth

Front 35

Valproate - teratogenic effect

Back 35

Inhibition of maternal folate absorption --> neural tube defects

Front 36

Warfarin - teratogenic effect

Back 36

Bone deformities, fetal hemorrhage, abortion, ophthalmologic abnormalities

Front 37

Fetal alcohol syndrome presentation

Back 37

Mental retardation, developmental retardation, microcephaly, holoprosencephaly, facial abnormalities, limb dislocation, heart/lung fistulas
*#1 cause of congenital malformation in US*

Front 38

Cocaine use - effect on pregnancy

Back 38

Fetal addiction, abnormal development
Placental abruption

Front 39

Smoking - effect on pregnancy

Back 39

Preterm labor, placental problems, IUGR, ADHD

Front 40

Iodide deficiency or overdose - effect on fetus

Back 40

Congenital goiter or hypothyroidism (cretinism)

Front 41

Maternal diabetes - effect on fetus

Back 41

Caudal regression syndrome (anal atresia, sirenomelia), congential heart defects, neural tube defects

Front 42

Vitamin A overdose - effect on fetus

Back 42

Spontaneous abortions, cleft palate, cardiac abnormalities

Front 43

X-rays - effect on fetus

Back 43

Microcephaly, mental retardation

Front 44

Dizygotic twins - rule of 2s

Back 44

2 eggs, 2 sperm
2 amniotic sacs
2 placentae

Front 45

Dichorionic, diamniotic MZ twins - time of splitting

Back 45

0-4 days: 2 cell --> morula

Front 46

Monochorionic, diamniotic MZ twins - time of splitting

Back 46

4-8 days: morula --> blastocyst

Front 47

Monochorionic, monoamniotic MZ twins - time of splitting

Back 47

8-12 days: blastocyst --> formed embryonic disc

Front 48

Monochorionic, monoamniotic conjoined MZ twins - time of splitting

Back 48

> 13 days

Front 49

Cytotrophoblast location + function

Back 49

Inner layer of chorionic villi
Mitotic, makes cells

Front 50

Syncytiotrophoblast location + function

Back 50

Outer layer of chorionic villi
Secretes hCG --> stimulates progesterone secretion by corpus luteum

Front 51

hCG function

Back 51

Stimulates corpus luteum to produce progesterone during 1st trimester

Front 52

Umbilical arteries - branch of + function

Back 52

Branch of internal iliac arteries
Carries deoxygenated blood to placenta

Front 53

Umbilical vein function

Back 53

Carries oxygenated blood from placenta to IVC (via ductus venosus)

Front 54

Urachal duct

Back 54

Duct between bladder and yolk sac in Week 3
Formed from allantois

Front 55

Patent urachus

Back 55

Failure of urachus to close.
Urine discharge from umbilicus

Front 56

Vesicourachal diverticulum

Back 56

Outpouching of bladder

Front 57

Vitelline duct

Back 57

Duct connecting yolk sac to midgut lumen

Front 58

Obliteration of vitelline duct occurs during

Back 58

Week 7

Front 59

Vitelline fistula

Back 59

Failure of vitelline duct to close.
Meconium discharge from umbilicus

Front 60

Meckel's diverticulum

Back 60

Partial closure of vitelline duct; patent portion attached to ileum

Front 61

1st aortic arch derivatives

Back 61

Maxillary artery (branch of external carotid)

Front 62

2nd aortic arch derivatives

Back 62

Stapedial, hyoid artery

Front 63

3rd aortic arch derivatives

Back 63

Common carotid,
Proximal internal carotid

Front 64

4th aortic arch derivatives

Back 64

Left: aortic arch
Right: proximal subclavian

Front 65

6th aortic arch derivatives

Back 65

Proximal pulmonary arteries
Ductus arteriosus