Mod 2: Embryology Flashcards
Heart forms in week…
Heart begins to beat in week…
Forms and begins to beat in week 3
Neural tube forms/closes during weeks…
4-5
Heart can be detected via ultrasound … weeks after fertilization
5-6
What is the first organ to form?
the heart
Somatopleure
Splanchnopleure
Somatopleure: somatic mesoderm layer + adj ECTOderm
Splanchnopleure: splanchnic mesoderm layer + adj ENDOderm
Thin layer of what germ layer coats the yolk sac?
mesoderm
What 2 chemokines required to form cardiogenic crescent?
What is the resulting chemokine in the crescent?
BMP 2,4 (periph) and WNT inhibitors (cranial)
NKX-2.5 – beginning of heart tube
Do atria or ventricles fuse last?
atria fuse last (more atrial defects than ventricle defects)
Forelimbs form (b/f or after) hindlimbs Anterior seals up (b/f or after) posterior
Forelimbs b/f hind
Anterior b/f post
Atria begin…in fetal heart
caudal, inferior
What are the 2 parts of the bulbis cordis?
What do they form?
Conus cordis
Truncus arteriosus
**will form: ventricles, pulmonary trunk, aorta
Lung buds grow off of what tube?
gut tube
Lung associated structures that are endodermal in origin?
mesodermal in origin?
Endodermal: larynx, trachea, bronchi, lungs
Mesodermal: CT, cartilage, muscle
What are the first 2 stages of lung development?
Embryonic (26 days - 6 weeks)
- -resp diverticulum arises
- -3 rounds of branching, primordia of lungs, lung lobes, bronchopulmonary segments
- -stem of diverticulum forms trachea and larynx
Pseudoglandular (6-16 weeks)
- -resp tree undergoes more branching
- -formation of terminal bronchioles
When does embryonic heart flow begin?
3rd week
Where does gas exchange occur in embryo?
placenta
Pharyngeal arches – each has what structures associated with it?
NAV, muscle, skeleton
Aortic arches arise from
aortic sac (most distal part of truncus arteriosus)
Aortic arch originates from
left dorsal aorta (pharyngeal arch 4)
Ductus arteriosus connects…
What does it become in adult
Connects pulmonary trunk and aorta
Becomes ligamentum arteriosus in adult
Aortic sac
place where pharyngeal arches branch from
What abdominal organ has 2 parts that later fuse?
pancreas (dorsal and ventral pancreatic buds)
Describe mesentery of foregut vs hindgut
Fore: dorsal and ventral mesenteries
Hind: dorsal mesentery only
What week are intestines retracted back into abdomen?
week 11
