Embryology Review For Step 1

Front 1

Fetal Landmark: Primitive Streak

Back 1

Week 3

Front 2

Fetal Landmark: Notochord

Back 2

Week 3

Front 3

Heart begins to beat

Back 3

Week 4

Front 4

Upper and lower limb bud formation?

Back 4

Week 4

Front 5

Genitalia have male/female characteristics

Back 5

Week 10

Front 6

Adenohypophysis, lens of eye, epithelial linings, epidermis.

Back 6

Surface ectoderm.

Front 7

Neurohypophysis, CNS neurons, oligodendrocytes, astrocytes.

Back 7

Neuroectoderm.

Front 8

Ependymal cells, Pineal gland.

Back 8

Neuroectoderm.

Front 9

ANS, dorsal root ganglia, cranial nerves.

Back 9

Neural crest.

Front 10

Melanocytes, chromaffin cells of adrenal medulla, parafollicular (C) cells of thyroid.

Back 10

Neural crest.

Front 11

Laryngeal cartilage, bones of skull.

Back 11

Neural crest.

Front 12

Dura mater, connective tissue.

Back 12

Mesoderm.

Front 13

Muscle, bone, cardiovascular structures, lymphatics, blood.

Back 13

Mesoderm.

Front 14

Urogenital structures, serous linings of body cavities (peritoneal), spleen.

Back 14

Mesoderm.

Front 15

Adrenal cortex, Kidneys.

Back 15

Mesoderm.

Front 16

Gut tube epithelium and derivatves.

Back 16

Endoderm.

Front 17

Lungs, liver, pancreas.

Back 17

Endoderm.

Front 18

Thymus, parathyroid, thyroid follicular cells.

Back 18

Endoderm.

Front 19

Nucleus pulposus of intervertebral disk.

Back 19

Notochord.

Front 20

Most susceptible period of pregnancy?

Back 20

3rd-8th weeks (organogenesis).

Front 21

Truncus arteriosus

Back 21

Ascending aorta and pulmonary trunk.

Front 22

Bulbus cordis.

Back 22

Smooth parts of left and right ventricle.

Front 23

Primitive ventricle.

Back 23

Trabeculated parts of left and right ventricle.

Front 24

Primitive atria.

Back 24

Trabeculated left and right atrium.

Front 25

Left horn of sinus venosus

Back 25

Coronary Sinus.

Front 26

Right horn of sinus venosus.

Back 26

Smooth part of right atrium.

Front 27

Right common cardinal vein and right anterior cardinal vein.

Back 27

SVC.

Front 28

Chorion consists of?

Back 28

Extraembryonic somatic mesoderm, cytotrophoblast, syncytiotrophoblast.

Front 29

Closes PDA, keeps patent PDA open?

Back 29

Indomethacin, Prostaglandins.

Front 30

Ligamentum teres hepatis?

Back 30

Umbilical vein.

Front 31

Medial umbilical ligaments

Back 31

Umbilical arteries.

Front 32

Median umbilical ligament.

Back 32

Allantois/Urachus.

Front 33

Aortic arch- #1

Back 33

Maxillary artery.

Front 34

Aortic arch- #2

Back 34

Stapedial artery and hyoid artery.

Front 35

Aortic arch- #3

Back 35

Common carotid artery and proximal part of internal carotid artery.

Front 36

Aortic arch #4.

Back 36

Aortic arch on left, proximal part of right subclavian artery.

Front 37

Aortic arch #6.

Back 37

Proximal part of pulmonary arteries and ductus arteriosus.

Front 38

Branchial clefts derived from?

Back 38

Ectoderm.

Front 39

Branchial arches derived from?

Back 39

Mesoderm.

Front 40

Branchial pouches derived from?

Back 40

Endoderm.

Front 41

Muscles of mastication, mandible, maxilla, malleus.

Back 41

Branchial arch 1 derivatives.

Front 42

Stapes, Styloid process. Stapedius, Stylohyloid.

Back 42

Branchial arch 2 derivatives.

Front 43

Stylopharyngeus.

Back 43

Branchial arch 3 derivatives.

Front 44

Most pharyngeal constrictors, cricothyroid, levator veli palatini.

Back 44

Branchial arch 4.

Front 45

All intrinsic muscles of larynx, except cricothyroid.

Back 45

Branchial arch 6.

(Branchial arch 5 makes no major developmental contribution).

Front 46

Branchial arch innervation:
1
2
3
4
6

Back 46

CN V
CN VII
CN IX
CN X- superior laryngeal branch.
CN X- recurrent laryngeal branch.

Front 47

Anterior 2/3 of tongue?

Back 47

Formed by branchial arch 1. Sensation via CN V3, taste via CN VII.

Front 48

Posterior 1/3 of tongue?

Back 48

3rd and 4th arches.
Sensation and taste mainly CN IX.
Extreme posterior CN X.

Front 49

Motor innervation of tongue?

Back 49

CN XII.

Front 50

1st branchial cleft?

2nd-4th clefts?

Back 50

External auditory meatus.

obliterated. if they proliferate lead to branchial cyst in the neck.

Front 51

1st branchial pouch?

Back 51

Middle ear cavity, eustachian tube, mastoid air cells.

1st pouch contributes to endoderm-lined structures of ear.

Front 52

2nd branchial pouch?

Back 52

Epithelial lining of palatine tonsil.

Front 53

3rd branchial pouch?

Back 53

Inferior parathyroids and thymus.

Front 54

4th branchial pouch?

Back 54

Superior parathyroids.

Front 55

Aberrant development of 3rd and 4th pouches?

Back 55

DiGeorge's syndrome. leads to T cell deficiency and hypocalcemia.

Front 56

Cleft lip?

Back 56

Failure of fusion of maxillary and medial nasal processes.

Front 57

Cleft palate?

Back 57

Failure of fusion of lateral palatine processes, the nasal septum, and/or the median palatine process.

Front 58

Diaphragm derived from?

Back 58

Septum transversum, pleuroperitoneal folds, body wall, dorsal mesentery of esophagus.

Front 59

Spleen comes from?

Back 59

Dorsal mesentery but supplied by artery of foregut.

Front 60

Mesonephric (wolffian duct) develops into?

Back 60

SEED: Seminal vesicles, epididymis, ejaculatory duct, and ductus deferens.

Front 61

Paramesonephric (mullerian) duct develops into?

Back 61

Fallopian tube, uterus, and part of the vagina.

Front 62

Genital homologues:
Genital tubercle

Back 62

Glans penis.
Glans clitoris.

Front 63

Urogenital sinus

Back 63

Vestibular bulbs, corpus spongiosum.
Bulbourethral glands, Greater vestibular glands.
Prostate gland, urethral and paraurethral glands.

Front 64

Urogenital folds

Back 64

Ventral shaft of penis. Labia minora.

Front 65

Labioscrotal swelling.

Back 65

Scrotum, labia majora.