Embryology Flashcards
what does the truncus arteriosus turns into?
the ascending aorta and pulmonary trunk
what does the bulbus cordis turn into?
the smooth parts of the left and right
the primitive atria and ventricle turn into the…
trebeculated part of the L and R atria and ventricles
What does the primitive pulmonary vein give rise to?
the smooth part of the L atrium
the left horn of the sinus venosus gives rise to what?
the coronary sinus (right behind and under the atria)
the right horn of the SV gives rise to…
the smooth part of the right atrium
the right atrium pools which veins together?
the Superior and Inferior vena cava
the left atrium pools which veins together?
the pulmonary veins!
the right common cardinal vein and right anterior cardinal vein give rise to what?
the superior vena cava
when does the heart start to beat spontaneously?
week 4 of development
(T/F) the heart is the first functional organ in vertebrate embryos
true
The septum _1_ grows toward _2_ cushions, narrowing _3_ primum. This is step 1 of septation of the (atria/ventricles)
- primum
- endocardial
- foramen
atria
Step 2 of atrial septation: the foramen secundum forms in the septum _1_. the foremen primum disappears.
primum
Step 4 of atrial septation: the septum _1_ expands and covers most of the foramen secundum. The residual foramen is the foramen _2_.
- secundum
- ovale
the septum secundum and septum primum fuse to form what?
the strial septum
What causes the formen ovale to close after birth?
An increase in **left atrial **pressure
what is the shape of the aorticopulmonary septum (Hint: this is also the way the heart contracts with each HB)
Spiral
the aorticopulmonary septum separates what two structures?
the ascending aorta and the pulmonary trunk
Blood entering he fetus through the umbilical vein is conducted via the _1_ _2_ into the _3_ IOT bypass the _4_ circulation
1-2. ductus venosus
- IVC
- Hepatic
In a fetus, the most highly oxygenated blood reaching the heart via the IVC is diverted through the _1_ _2_ and pumped out the _3_ to the head and body.
1-2. foramen ovale
- aorta
which chamber of the heart has the highest pressure? The lowest pressure?
highest? L ventricle
lowest? R atrium
what drug is used to close a patent ductus arteriosus?
indomethacin
What is used to keep a PDA open?
exogenous administration of prostaglandins
ribs originate (medially/laterally) and approach the midline (anteriorly/posteriorly).
laterally
anteriorly
if clavicles fail to migrate, what arises (it’s a congenital defect)?
a sternal cleft
what is ectopia cordis?
when a child is born with their heart outside the chest wall
what are the five dilations of the primitive heart tube (in order)?
truncus arteriosus
bulbus cordis
primitive ventricles
primitive atria
sinus venosus
what is tetralogy of fallot?
abnormal neural crest cell migration that leads to the anterior displacement of the aorticopulmonary septum
what is seen on an exam of a patient with tetralogy of fallot?
PROVe:
pulmonary stenosis
right ventricular hypertrophy
overriding aorta
ventricular septal defect
What syptoms are seen in patients with tetralogy of fallot?
What is the treatment?
squatting to relieve cyanosis
cyanosis following crying or feeding
blue baby syndrome
enlarged right ventricle
treatment: surgery
a defect in te endocardial cushion would lead to what other defect?
a defect in the atrioventricular septum
what is the adult derivative of the first aortic arch?
part of the Maxillary artery
what is the adult derivative of the second aortic arch?
the stapedial artery and hyoid artery
what is the adult derivative of the third aortic arch?
the common carotid artery and the proximal internal carotid artery
what is the adult derivative of the fourth aortic arch?
the aortic arch and the proximal part of the right subclavian artery
what is the adult derivative of the fifth aortic arch?
there is none. the fifth arch regresses in humans.
what is the adult derivative of the sixth aortic arch?
the proximal pulmonary arteries and the ductus arteriosus
What is the change in hematopoiesis during gestation?
yolk sac, liver, spleen, then bone marrow
vasculogenesis occurs in which gestational layer?
splanchnic mesoderm
Angiogenesis is regulated by what transcription factor?
VEGF: Vascular endothelial growth factor
What is the name of the artery and vein that is supplied by the yolk sac? What do they eventually become?
The Vitelline Artery and Vein? Becomes vasculature of abdomen
What are the two shunts of the fetal heart?
the ductus arteriosus and formen ovale
An adult has a condition where the foramen secundum is formed but there is excess resorption of the septum primum. This would cause what defect in blood flow? What is this condition called?
blood flow from the left atrium to the right atrium because there is higher pressure in the left atrium in an adult.
this is an Atrial Septal Defect (ASD)
what two structures surround the interventricular foramen? How does the IV foramen start to disappear?
the endocardial cushion and the muscular interventricular septum
the endocardial cushion and muscular IV septum fuse
if the membranous part of the IV septum does not form, a newborn will have blood flowing in what way?
from the left ventricle to the right ventricle because the pressure in the left ventricle is higher.
what type of cells form the truncus arteriosus?
neural crest cells
what is on top: the pulmonary trunk or the aorta?
The pulmonary trunk
what portion of the interventricular septum closes the IV foramen?
the membranous portion
what do the cardinal veins form?
the major veins of the body
What nerves supply the larynx?
What do they wrap around?
the recurrent laryngeal nerves
on the right: the nerve wraps under the right subclavian artery.
onthe left: the nerve wraps under the ductus arteriosus (ligamentum arteriosus in adults)
what is the embryonic source of the internal carotid artery?
the dorsal aorta and 3rd arch
what is the embryonic source of the external carotid artery?
growth off of the third arch
what is the embryonic source of the common carotid artery
3rd aortic arch
what is the embryonic source of the right subclavian artery?
the rigth 4th arch and the th intersegmental dorsal aorta
what is the embryonic source of the left subclavian artery?
the left 7th intersegmental
what is the embryonic source of the brachiocephalic artery?
the aortic sac
what is the embryonic source of the aortic arch?
the truncus arteriosus, aortic sac, left 4th arch, left dorsal aorta.
what is the embryonic source of the pulmonary trunk?
the truncus arteriosus
what is the embryonic source of the pulmonary arteries?
the 6th aortic arches and buds off of 6th arches
what is the embryonic source of the ligamentum arteriosum?
the left 6th arch
the ductus venosus bypasses what organ?
the liver
why does the ductus arteriosus constrict at birth (4)?
- oxygen tension rises
- bradykinin is release from the lungs and this stimulates smooth muscle constriction
- prostaglandins from the mother are no longer present
- backward flow of blood through the ductus causes it to become occluded
what is the role of a mother’s prostaglandins in a fetus?
it keeps the ductus arteriosus open
what are the five phases of the lower respiratory system?
embryonic (wk 4-5)
pseudoglandular (5-17)
canalicular (16-25)
terminal sac (24-40)
alveolar (late fetal - 8yo)
what gestational layer is on the ventral wall of the foregut?
the endoderm
The (R/L) grows more verticaly oriented while the (R/L) lung grows more lateral.
R, L
What is the first pulmonic embryonic strucutre that branches off of the pharyngeal foregut?
The respiratory diverticulum
what does the respiratory diverticulum become?
the trachea and lung buds
if you were to choke on a peanut, which lung would it be in?
The right side. This side of the lung grows larger and straighter than the left.
what is parenchyma?
the essential or functional parts of an organ
What does the endoderm (from the pharyngeal foregut) contribute to the embryonic phase?
lung parenchyma (respiratory tract epithelium and glands)
What does the mesoderm (from the pharyngeal foregut) contribute to the embryonic phase (3)?
- pleura
- smooth muscle
- cartilage and connective tissue
What does the ectoderm (from the pharyngeal foregut) contribute to the embryonic phase? Be specific.
neural innervation: phrenic nerve, intercostal nerves
What adult organs are derived from the lower respiratory system?
the Larynx, Trachea, Lungs
What are the two derivatives of the lateral plate mesoderm?
splanchnic mesoderm (organs)
somatic mesoderm (muscle)
The coelem is the cavity in the mesoderm. What does it become in the lungs?
the pleural space
What is significant about the late canalicular period
life outside of the womb is rare but possible
what is significant about the sacular period (4)?
- surfactant production
- lungs begin to mature
- type 1 pneumocytes dominate
- life is possible outside of the womb
what is significant about the alveolar period (3)?
alveoli increase in number
respiratory system continues to divide
continues until 8 yo
a full complement of mature alveoli are present by how many weeks?
37
if a baby is born prematurely before type 2 cells make enough pulmonary surfactant, what would you expect?
difficulty inflating the lungs
when do fetal breathing movements begin?
around 20 weeks
what happens to fluid that remains in the lungs after birth?
it is absorbed
- At what week does the fetus have enough mature structure to breath on its own if born prematurely?
- What other structures develop during this phase (3)?
late canalicular period: week 28
strucutre: pulmonary capillaries (expand to create large surface area for gas exchange), alveolar ducts and alveolar precursors
the lung alveoli are derived from (splanchnic Mesoderm/ectoderm/endoderm/somatic mesoderm/coelem)?
endoderm
the outflow tracts of the ventricles are formed from which heart derivative?
the bulbis cordis
where is the aortic sac located?
just above the truncus arteriosus
