foetal development

Question 1

how many umbilical arteries are there

Answer 1

2

branch of the internal iliac arteries

Question 2

what do the umbilical arteries form

Answer 2

medial umbilical ligament

Question 3

what does the umbilical vein form

Answer 3

ligamentum teres

Question 4

how does blood bypass the liver

Answer 4

ductus venosus

Question 5

what causes constriction of the DA

Answer 5

smooth muscle constriction due to increase O2
decreased levels of prostaglandins
prostaglandin receptors decrease

anatomical closure due to thickening of the tunica intima

Question 6

what are the two layers in the bilaminer disc

Answer 6

epiblast and hypoblast

Question 7

where does the heart tube form

Answer 7

mesoderm from angiogenetic clusters at the cephalic end of the trilaminar disc

Question 8

when does heart development and cephalo caudal folding start

Answer 8

day 18

Question 9

at what end is the truncus arteriosus

Answer 9

cephalic

Question 10

at what end is the sinus venosus

Answer 10

caudal

Question 11

what way does the heart normally fold

Answer 11

towards the right, which pushes the apex left

Question 12

what does the venous end receive

Answer 12

blood from the cardinal, umbilical and vitelline veins

Question 13

what are endocardial cushion cells derived from

Answer 13

neural crest cells

Question 14

what do the endocardial cushions form

Answer 14

interatrial septum
membranous part of interventricular septum
AV valves
PT and aorta from truncus arteriosus

Question 15

in which septum does the foramen ovale form

Answer 15

septum secundum

Question 16

what is the smooth part of the atrium derived from

Answer 16

sinus venosus

Question 17

what is the aorta derived from

Answer 17

truncus arteriosus

Question 18

what are the maxillary arteries derived from

Answer 18

1st pharyngeal arch

Question 19

what forms the common carotid arteries

Answer 19

3rd arch

Question 20

what forms the aortic arch

Answer 20

left 4th arch

Question 21

what forms the right subclavian

Answer 21

right 4th arch

Question 22

what forms the pulmonary trunk and DA

Answer 22

left 6th arch

Question 23

what would you hear with a PDA

Answer 23

continuous machinery murmur

Question 24

what does the first pharyngeal groove form

Answer 24

external auditory meatus

Question 25

what forms where a pouch and groove meet

Answer 25

a membrane

Question 26

what does the first membrane form

Answer 26

the tympanic membrane

Question 27

how many pharyngeal arches are there

Answer 27

6

Question 28

what does each arch consist of

Answer 28

cartilaginous element, artery and cranial nerve

Question 29

what does the septum transversum form

Answer 29

the central tendon of diaphragm and mesentery

Question 30

what does the respiratory diverticulum form

Answer 30

the lung buds

Question 31

what is the tracheooesophageal septum

Answer 31

separates the trachea and oesophagus

Question 32

what can be a result of oesophageal atresia

Answer 32

polyhydramnios

Question 33

what do the pericardio peritoneal canals form

Answer 33

the pleural cavities

Question 34

what are the 4 stages of lung development

Answer 34

pseudoganglia cacanalicular terminal saccular alveolar

Question 35

what happens in the pseudoganglia stage

Answer 35

formation as far as terminal bronchioles

Question 36

what happens in canalicular stage

Answer 36

respiratory bronchioles and alveolar ducts form | increasing vascularisation

Question 37

what happens in the terminal saccular stage

Answer 37

alveoli form | type 2 pneumocytes form

Question 38

when is the alveolar period

Answer 38

28 weeks until childhood | increase in the number of alveoli

Question 39

when is foetal survival usually possible

Answer 39

28 weeks with sufficient surfactant and weighing at least one kg risk of respiratory distress syndrome

Question 40

name some possible birth defects associated with the lungs

Answer 40

pulmonary agenesis or hypoplasia

Question 41

what are the origins of the diaphragm

Answer 41

septum transversum pleuroperitoneal membranes mesentery of the oesophagus (forms crura) ingrowth of the body wall

Question 42

name the types of diaphragmatic hernia

Answer 42

posterolateral, anterior and central