embryology

Question 1

what structures in the developing face must fuse to form the upper lip and jaw?

Answer 1

maxillary prominence and medial nasal prominences

Question 2

what embryonic structures contribute to the development of the face?

Answer 2

frontonasal prominences and first and second pharyngeal arches

Question 3

to what structures do the 3rd and 4th pouches contribute?

Answer 3

parathyroid glands and thymus

Question 4

which cranial nerves are associated with the pharyngeal arches?

Answer 4

CN V, VII, IX, X

Question 5

to what structures in the head and neck do neural crest cells contribute?

Answer 5

cartilage bars in each of the pharyngeal arches leading to development of the skeleton of the face

Question 6

which structures are secondarily retroperitoneal?

Answer 6

pancreas, duodenum, descending colon

Question 7

which structures are retroperitoneal?

Answer 7

pancreas, aorta, kidneys

Question 8

how does the true kidney develop?

Answer 8

from intermediate mesoderm in the pelvis under induction by the ureteric bud

Question 9

describe the development and fate of the notochord

Answer 9

formed during gastrulation

drives neurulation and forms the nucleus pulposus of the IV disks

Question 10

during development the gut tube is suspended by mesenteries. which region of the developing gut tube are suspended by both dorsal and ventral mesenteries?

Answer 10

foregut only

Question 11

which structures have mesenteries?

Answer 11

jejunum, ileum, stomach

Question 12

in a patient with an inflamed Meckel’s diverticulum, where would the pain be felt initially?

Answer 12

-periumbilical region
- abnormal remnant of the vitelline duct connecting the primitive gut tube to the umbilical cord at the midgut during embryonic life.
- connection permits physiological herniation of the midgut loop
midgut= periumbilical region pain

Question 13

in which week of development does the embryo fold?

Answer 13

4th

Question 14

does the folding of the embryo change the position of the cariogenic field?

Answer 14

yes

• moves from cranial to buccopharyngeal membrane to a position ventrally within the neck
• ultimately thorax of the embryo as a consequence of folding of the embryo in the cephalocaudal plane

Question 15

which embryonic tissue gives rise to the cardiovascular system?

Answer 15

mesoderm

- specialised region of the mesoderm = cariogenic fields

Question 16

from which structure does the vas deferens develop?

Answer 16

mesonephric duct

- supported by androgens

Question 17

from which structure does the uterus develop?

Answer 17

paramesonephric duct

- absence of testis derived MIH to develop into the uterus, uterine tubes and the upper vagina

Question 18

a 16/o girl presents with primary amenorrhoea. physical examination reveals female external genitalia, but testosterone levels are in excess of a normal girl. Karyotyping is XY. what is the diagnosis

Answer 18

androgen insensitivity syndrome

Question 19

from which tissue do the gonads develop?

Answer 19

intermediate mesoderm in the abdomen

- gonads then descend through the abdomen

Question 20

on examination a 3y/o boy is found to have a urethral opening which extends posteriorly along the ventral surface of the shaft of the penis
what is the most likely cause of this structural anomaly?

Answer 20

failure of the urogenital folds to fuse

- penile urethra

Question 21

from which structure does the bladder develop?

Answer 21

urogenital sinus

Question 22

which part of the nervous system mediates sensation from above and below the pectinate line respectively?

Answer 22

visceral and somatic

• above line: derived from handgun and has splanchnic innervation
• below line: ectoderm of the proctodeum which has a somatic supply

Question 23

what Is the etiology of metal HR accelerations in utero?

Answer 23

• response to metal movement

Question 24

what is the normal metal pO2?

Answer 24

4kPa

Question 25

what is the normal fetal HR?

Answer 25

100-160 bpm

Question 26

which prenatal diagnostic test has the highest risk of pregnancy loss?

Answer 26

chorionic villus sampling

Question 27

what treatment can be given to promote fetal lung development should premature delivery be unavoidable?

Answer 27

corticosteroids

- promote surfactant production in fetal lungs

Question 28

what is the most common cause of morbidity in premature infants?

Answer 28

respiratory distress syndrome