Foundations of Embryology

Question 1

Gametes arise from:

Answer 1

Primordial germ cells (PGCs)

Question 2

Once in the gonads, PGC’s differentiate into

Answer 2

oogonia/spermatagonia

Question 3

Follicular cells originate from _____

Answer 3

the surface epithelium

Question 4

Primary follicle cells with its surrounding flat epithelial cells

Answer 4

Primordial follicle

Question 5

Diplotene stage

Answer 5

Primary oocytes are arrested at prophase I until puberty

Question 6

Week 1 following fertilization

Answer 6

Morula (ball of cells) > blastula (hollow ball)

Question 7

Week 2 following fertilization

Answer 7

Implantation in the uterus (normal) or in the fallopian tubes (most common ectopic) or other surrounding organs (GI, colon)

HCG is detectable and is secreted by corpus luteum to support pregnancy

Question 8

Week 3 following fertilization

Answer 8

Gatrulation occurs - formation of the 3 layer embryo

Ectoderm
Endoderm
Mesoderm

Question 9

Ectoderm

Answer 9

forms the central and peripheral nervous system and epithelium of the skin

Question 10

Mesoderm

Answer 10

Forms the body connective tissues: blood, bone, muscle, connective tissue skin, gastrointestinal and respiratory tracts

Question 11

Endoderm

Answer 11

Forms epithelium of the gastrointestinal and respiratory tracts, gastrointestinal tract and endocrine organs

Question 12

Neuralation

Answer 12

Sepearation of the ectoderm
Separates the neural tissue from the skin
Notochord develops in mesoderm - induces neural plate formation in ectoderm - grow together to make neural tube

Question 13

Somitogenesis

Answer 13

Segmentation of the mesoderm into somites

Forms the axial body plan

Question 14

Zona pellucida

Answer 14

Needs to disintegrate for implantation to occur