foetal development Flashcards
how many umbilical arteries are there
2
branch of the internal iliac arteries
what do the umbilical arteries form
medial umbilical ligament
what does the umbilical vein form
ligamentum teres
how does blood bypass the liver
ductus venosus
what causes constriction of the DA
smooth muscle constriction due to increase O2
decreased levels of prostaglandins
prostaglandin receptors decrease
anatomical closure due to thickening of the tunica intima
what are the two layers in the bilaminer disc
epiblast and hypoblast
where does the heart tube form
mesoderm from angiogenetic clusters at the cephalic end of the trilaminar disc
when does heart development and cephalo caudal folding start
day 18
at what end is the truncus arteriosus
cephalic
at what end is the sinus venosus
caudal
what way does the heart normally fold
towards the right, which pushes the apex left
what does the venous end receive
blood from the cardinal, umbilical and vitelline veins
what are endocardial cushion cells derived from
neural crest cells
what do the endocardial cushions form
interatrial septum
membranous part of interventricular septum
AV valves
PT and aorta from truncus arteriosus
in which septum does the foramen ovale form
septum secundum
what is the smooth part of the atrium derived from
sinus venosus
what is the aorta derived from
truncus arteriosus
what are the maxillary arteries derived from
1st pharyngeal arch
what forms the common carotid arteries
3rd arch
what forms the aortic arch
left 4th arch
what forms the right subclavian
right 4th arch
what forms the pulmonary trunk and DA
left 6th arch
what would you hear with a PDA
continuous machinery murmur
what does the first pharyngeal groove form
external auditory meatus
what forms where a pouch and groove meet
a membrane
what does the first membrane form
the tympanic membrane
how many pharyngeal arches are there
6
what does each arch consist of
cartilaginous element, artery and cranial nerve
what does the septum transversum form
the central tendon of diaphragm and mesentery
what does the respiratory diverticulum form
the lung buds
what is the tracheooesophageal septum
separates the trachea and oesophagus
what can be a result of oesophageal atresia
polyhydramnios
what do the pericardio peritoneal canals form
the pleural cavities
what are the 4 stages of lung development
pseudoganglia
cacanalicular
terminal saccular
alveolar
what happens in the pseudoganglia stage
formation as far as terminal bronchioles
what happens in canalicular stage
respiratory bronchioles and alveolar ducts form
increasing vascularisation
what happens in the terminal saccular stage
alveoli form
type 2 pneumocytes form
when is the alveolar period
28 weeks until childhood
increase in the number of alveoli
when is foetal survival usually possible
28 weeks with sufficient surfactant and weighing at least one kg
risk of respiratory distress syndrome
name some possible birth defects associated with the lungs
pulmonary agenesis or hypoplasia
what are the origins of the diaphragm
septum transversum
pleuroperitoneal membranes
mesentery of the oesophagus (forms crura)
ingrowth of the body wall
name the types of diaphragmatic hernia
posterolateral, anterior and central
