Important genes of embryogenesis/Early Fetal Devo EC Flashcards Preview

Evan's Step 1 Prep Material > Important genes of embryogenesis/Early Fetal Devo EC > Flashcards

Flashcards in Important genes of embryogenesis/Early Fetal Devo EC Deck (26):
1

Produced at the base of limbs in zone of polarizing activity. Involved in patterning along anterior-posterior axis. Involved in CNS development; mutation can cause holoprosencephaly.

Sonic hedgehog gene

2

Produced at apical ectodermal ridge (thickened ectoderm at distal end of each developing limb). Necessary for proper organization along dorsal-ventral axis.

Wnt-7 gene

3

Produced at apical ectodermal ridge. Stimulates mitosis of underlying mesoderm, providing for lengthening of limbs.

FGF gene

4

Involved in segmental organization of embry in craniocaudal direction. Mutations cause appendages in wrong locations.

Homeobox (Hox) genes

5

Week 1 of embryogenesis

Zygote (day 2), Morula (day 3), Blastocyst (day 5), Implantation (day 6)

hCG secretion begins after implantation (+ pregnancy test)

6

Week 2 of embryogenesis

Bilaminar disc (Epiblast [will become 3 layers] and Hypoblast [becomes yolk sac])

"2 weeks=2 layers"

7

Week 3 of embryogenesis

Trilaminar disc/Gastrulation

Primitive streak, Notochord, Mesoderm organization, Neural plate begin to form

"3 weeks=3 layers"

8

Embryonic period (weeks 3-8)

Neural tube formed by neuroectoderm and closes by week 4

Organogenesis

Extremely susceptible to teratogens

9

Week 4 of embryogenesis

Heart begins to beat

Limb buds begin to form

"4 weeks=4 limbs"

10

Week 8 of embryogenesis

Start of fetal period

Fetal movement/looks like a baby

11

Week 10 of embryogenesis

Genitalia have male/female characteristics

12

Process that forms trilaminar embryonic disc. Establishes the ectoderm, mesoderm, and endoderm germ layers. Starts with the epiblast invaginating to form the primitive streak.

Gastrulation

13

What are the three divisions of the ectoderm?

Surface ectoderm
Neuroectoderm
Neural crest

14

Adenohypophysis (from Rathke's pouch), lens, epithelial lining of oral cavity, sensory organs of ear, olfactory epithelium. Epidermis, anal canal below pectinate line, parotid, sweat, and mammary glands.

Surface ectoderm

15

Craniopharyngioma

Benign Rathke's pouch tumor with cholesterol crystals and calcifications

16

Brain, retina/optic nerve, and spinal cord

Neuroectoderm

17

PNS, Melanocytes, Chromaffin cells of adrenal medulla, Parafollicular cells of thyroid, Pia and Arachnoid, Bones of skull, odontoblasts, aorticopulmonary septum.

Neural crest

18

Muscle, bone, CT, Serous lining of body cavities, spleen, CV structures, Lymphatics, Blood, Wall of gut tube, Wall of bladder, Urethra, Vagina, Kidneys, Adrenal cortex, Dermis, Gonads

Mesoderm

19

Mesoderm defects

VACTERL

Vertebral defects
Anal atresia
Cardiac defects
T-E fistula
Renal defects
Limb defects (bone and muscle)

20

Induces ectoderm to form neuroectoderm (neural plate). It's only postnatal derivative is the nucleus pulposus.

Notochord (mesoderm)

21

Gut tube epithelium (including anal canal above pectinate line), lungs, liver, gallbladder, pancreas, eustachian tube, thymus, parathyroid, thyroid follicular cells)

Endoderm

22

Absent organ due to absent primordial tissue

Agenesis

23

Absent organ despite primordial tissue

Aplasia

24

Extrinsic disruption; occurs after the embryonic period

Deformation

25

Incomplete organ development; primordial tissue present.

Hypoplasia

26

Intrinsic disruption; occurs during embryonic period (weeks 3-8)

Malformation

Decks in Evan's Step 1 Prep Material Class (72):