Embryo Exam II

Question 1

What is working as lungs in embryo?

Answer 1

placenta

Question 2

What is persistent truncus arteriosus?

Answer 2

PTA is partial development of AP septum. PTA is usually by VSD.
(congenital heart defects)

Question 3

When would I see a “blue” baby?

Answer 3

congenital heart defects… marked cynosis (Rt-lt) shunt

PTA (persistent truncus arteriosus)

Question 4

What is transposition of great vessels?

Answer 4

nonspiral development of AP septum

incompatible with life unless shunt like VSD, patent forament ovale or patent ductus arteriosus exists

Question 5

What is the tetralogy of Fallot? (congential heart defects)

Answer 5

PROVE
Pulmonary stenosis
Right ventricular hypertrophy
Overriding Aorta
Ventricular septal defect (VSD)

marked cynosis (Rt-lt shunt)

Question 6

Describe fetal circulation:
Fetal structure given, give adult remnant:

1. right and left umbilical arteries
2. left umbilical vein
3. ductus venosus
4. foramen ovale
5. ductus arteriosus

Answer 6

adult remnant:

1. right and left umbilical arteries - medial umbilical ligaments
2. left umbilical vein - ligamentum teres
3. ductus venosus - ligamentum venosum
4. foramen ovale - fossa ovale
5. ductus arteriosus -ligamentum arteriosum

Question 7

What do the following aortic arches give?

3, 4, 6 (left side)

Answer 7

3- common carotid and first part of internal carotid arteries

4 - aortic arch on left, subclavian artery on right

6 left side- left pulmonary artery and ductus arteriosus

Question 8

Define the following common embryological terms:
recanalization:
stenosis:
atresia:

Answer 8

Recanalizatoin: re-open the lumen/gut tube
Stenosis: partial/narrowing of the lumen/gut tube
Atresia: complete closure of the lumen/gut tube

Question 9

Midgut rotation.

Answer 9

counter-clockwise rotation of midgut 270 degrees total

super superior mesenteric a. as axis

Question 10

When does physiological hernation occur.

Answer 10

in development of midgut

happens in intestine between weeks 6-10

Question 11

Describe the following congenital anomaly: Meckel’s (ileal) diverticulum.

Answer 11

remnant of vitelline duct

Question 12

Describe the congenital anomaly: omophalocele

Answer 12

result from failure of return of the intestine to the abdominal cavity.

Question 13

Describe the cloaca.

Answer 13

expanded terminal part of hind gut
receives the allantois
divided by urorectal septum

mainly endoderm (any gut tube is endoderm)

Question 14

What does the urorectal septum divide the cloaca into?

Answer 14

urogenital sinus (anterior) and anal canal (posterior)

Question 15

What are urinary bladder and trigone area?

kidneys and gonads?

Answer 15

urinary bladder should be endoderm

trigone area, kidneys, and gonads are mesoderm

Question 16

Describe the mesonephros:

mesonephric tubules

Answer 16

excretory organs that in males give vas deferens, epididymis and ejaculatory ducts

Question 17

What do the mesonephric ducts give?

Answer 17

uteteric bud and trigone

Question 18

The metanephros lead to permanent kidney and develop from what two sources?

Answer 18

ureteric bud- ureter, renal pelvis, calices, and collecting tubules

metanephrogenic blastema- nephrons (functional unit of kidney)

Question 19

Describe the urinary bladder.

Answer 19

continuous with allantois, urachus, median umbilical ligament

as bladder enlarges, distal parts of mesonephratic ducts are incorporated into its dorsal wall (trigone of the bladder)

all endoderm (urogenital sinus) except trigone (mesodermal)