Embryology

Question 1

Urogenital structures arising from intermediate mesoderm (5)

Answer 1

• Kidney (pronephros, mesonephros, metanephric ducts/tubules)
• Ureter
• Adrenal cortex
• Gonads
• Reproductive ducts (Mesonephric/Wolffian + Paramesonephric/Mullerian)

Question 2

Primoridal germ cells begin their migration from _ and end up in _

Answer 2

• Yolk sac

- Genital ridges (developing gonads)

Question 3

What initiates primordial germ cell migration?

Answer 3

The presence of two sex chromosomes

Question 4

Wolffian ducts develop into? (4)

Answer 4

SEED

Seminal vesicles, Epididymis, Ejaculatory duct, Ductus deferens

Question 5

Mullerian ducts develop into? (4)

Answer 5

Fallopian tubes, Uterus, Cervix, Upper vagina

Question 6

Genital tubercle develops into (male and female)

Answer 6

Male = Glans of penis
Female = Glans of clitoris

Question 7

Urethral folds develop into (male and female)

Answer 7

Male = corpora cavernosum, corpus spongiosum, shaft of penis
Female = bulb of vesibule, labia minora

Question 8

Genital swelling develops into (male and female)

Answer 8

Male = scrotum
Female = labia majora

Question 9

Anti-Mullerian Hormone is part of what family?

Answer 9

TGF-beta superfamily of peptide growth factors

Question 10

5-alpha reductase type 1 locations

Answer 10

Liver and Skin

Question 11

5-alpha reductase type 1 functions

Answer 11

male body hair patterns

Question 12

5-alpha reductase type 2 locations

Answer 12

skin of the genitals and skin on the scalp

Question 13

5-alpha reductase type 2 functions

Answer 13

• masculinization of the external genitalia in utero

- male pattern baldness

Question 14

Kleinfelter Syndrome genotype

Answer 14

XXY

Question 15

male + hypogonadism + gynecomastia + above average height + infertile =

Answer 15

Kleinfelter Syndrome

Question 16

Turner Syndrome genotype

Answer 16

XO

Question 17

female + short stature + streak gonad/infertile + no puberty =

Answer 17

Turner Syndrome

Question 18

Kleinfelter levels of LH and FSH (elevated or decreased)

Answer 18

Elevated LH, Elevated FSH due to lack of T feedback (low T due to hypogonadism)

Question 19

SF1 function?

Answer 19

• Transcription factor for DAX1
• Stimulate AMH/MIS production in Sertoli cells
• Stimulate T production within Leydig cells

Question 20

One copy of DAX1 function?

Answer 20

-Testes differentiation

Question 21

SRY function?

Answer 21

Sertoli cell and Leydig cell differentiation

Question 22

Arteries of the developing gut (3)

Answer 22

Foregut - Celiac trunk
Midgut - Superior mesenteric artery
Hindgut - Inferior mesenteric artery

Question 23

Developing heart: Bulbus cordis ->

Answer 23

Smooth RV + LV

Question 24

Developing heart: Truncus arteriosus ->

Answer 24

ascending aorta + pulmonary trunk

Question 25

Developing heart: Primitive Ventricles ->

Answer 25

Trabeculated RV + LV

Question 26

Developing heart: Primitive Atria ->

Answer 26

R + L auricles

Question 27

Developing heart: Sinus venosus ->

Answer 27

Coronary sinus + RA

Question 28

Developing heart: Ductus arteriosus ->

Answer 28

Ligamentum arteriosum

Question 29

Function of ductus arteriosus?

Answer 29

Connects the fetal pulmonary artery and fetal aorta

Question 30

Function of the foramen ovale?

Answer 30

Connects the RA to the LA (R->L shunt)

Question 31

Function of the ductus venosus?

Answer 31

Connects the umbilical vein (carrying oxygenated blood) to the IVC

Question 32

Developing heart: Umbilical vein + Ductus venosus ->

Answer 32

Ligementum teres

Question 33

Developing heart: Umbilical arteries ->

Answer 33

Medial umbilical ligaments

Question 34

Ostium primium is made by: (2)

Answer 34

Septum primium growing downwards towards the AV cushions

Question 35

Ostium secundum is formed when?

Answer 35

Superior septum primium begins to degenerate

Question 36

Developing heart: Common cardinal veins ->

Answer 36

Superior vena cava

Question 37

Interventricular foramen is made via?

Answer 37

muscular interventricular septum grows upwards and does not quite reach the AV cushions therefore leaving a space.

Question 38

Aorticopulmonary septum is derived from?

Answer 38

neural crest cells

Question 39

Omphalocele

Answer 39

Failure of herniated midgut to return to the abdominal cavity during the 5th week of development. Herniated intestines are covered in peritoneal membrane and is midline to the umbilicus.

Question 40

Gastroschisis

Answer 40

Full thickness abdominal wall defect allowing small or large bowel to escape. Will not be covered by peritoneal membrane. Protrudes lateral to the umbilicus.

Question 41

Midgut volvulus presents as?

Answer 41

Bilious emesis, abdominal pain and distension, rectal bleeding

Question 42

Fixed split S2 is found in which heart defect and which beat comes first (A or P)?

Answer 42

ASD | Pulmonic closes first

Question 43

Trisomy 21 heart defect

Answer 43

Persistent AV canal, VSD, ASD

Question 44

Umbilical vein oxygen content - high, moderate, low?

Answer 44

High O2 content

Question 45

Umbilical artery oxygen content - high, moderate, low?

Answer 45

Moderate O2 content

Question 46

DiGeorge Syndrome is the underdevelopment of what 2 things?

Answer 46

3rd and 4th branchial pouches