Embryology Flashcards
What structure is derived from the prochordal plate?
Mouth
What is the only ORGAN supplied by the FOREGUT artery that is of MESODERMAL origin?
Spleen
In which direction and how far does the gut rotate?
counterclockwise 270 degrees
What structure connects the primitive gut to the yolk sac?
The yolk stalk (vitelline duct)
What is the artery of the embryonic foregut?
Celiac artery
When does the primitive gut herniate out of the embryo?
When does it return back in to the embryo?
6 weeks
10 weeks
What 2 pathologic conditions occur when the gut does not return to the embryo?
Omphalocele and gastroschisis
around what structure does the midgut rotate?
Superior mesenteric artery
What 3 things cause the indifferent gonad to become a testis and where do they come from?
- Testis-determining factor (TDF) from the short arm of the Y chromosome
- Mullerian inhibiting factor (MIF) from sertoli cells
- Testosterone from leydig cells
Where does the embryologic foregut end?
At the first part of the duodenum
What is the artery of the embryonic hindgut?
inferior mesenteric artery
what 3 embryonic cell layers form the chorion
- cytotrophoblast
- Syncytiotrophoblast
- Extraembryonic mesoderm
Which neuropore closes last?
Caudal - and it is the first to open too
What is the artery of the embryonic midgut
Superior mesenteric artery
From where are nephrons derived embryonically
metanephros
What are the 5 derivatives of the ventral mesentery?
1 falciform ligament
2. hepatoduodenal ligament
3. hepatogastric ligament
4 and 5. Coronary and triangular ligaments of the liver
All else is dervied from the dorsal mesentery
When do the septum primum and the septum secundum of the heart fuse?
After birth
The cerebral cortex is a derivative of what?
The telencephalon
The umbilical vein of the embryo becomes ___ adult structure
Ligamentum teres
The ductus venosus of the embryo becomes ___ adult structure
Ligamentum venosum
The foramen ovale of the embryo becomes ___ adult structure
Fossa ovale
The ductus arteriosus of the embryo becomes ___ adult structure
Ligamentum arteriosum
The umbilical artery of the embryo becomes ___ adult structure
Medial umbilical ligament
Where does the hindgut end?
Superior portion of the anal canal
Where does the midgut end?
at the right 2/3 of the transverse colon
from where is the tongue musculature derived?
occipital somaties
What 2 brachial arches contribute to the formation of the ANTERIOR 2/3 of the tongue?
first and some of the second
what are the 2 fourth pharyngeal pouch derivatives
Superior parathyroid glands and the ultimobranchial body
what 2 structures are derived from the fourth aortic arch?
arch of the aorta and the R subclavian artery
What adult structures are derived from preotic somites?
muscles of the internal eye
What structure is derived from the first pharyngeal pouch?
The middle ear
What 2 branchial arches contribute to the POSTERIOR 2/3 of the tongue?
third and part of fourth
What are the 2 third pharyngeal pouch derivatives?
inferior parathyroid glands and the thymus
What structure is derived from the first aortic arch?
Maxillary artery
from what are the urinary bladder and the urethra derived?
urogenital sinus
from what are the pumonary trunk and the ascending aorta derived?
Truncus arteriosum
What disorder will result when there is failure of the urachus to close, causing a leakage of urine out of the umbilicus?
Urachal fistula
The common carotid and internal carotid arteries are derivatives of what embryonic structure?
Third aortic arch
The palatine tonsils are derived from what embryonic structure?
second pharyngeal pouch
What are the sixth aortic arch derivatives?
R and L pulmonary arteries and the ductus arteriosus
The stapedial artery is derived from what?
Second aortic arch
The mesonephric ducts contribute to what renal structures?
Collecting ducts, calyx, renal pelvis, and ureters
Of what embryonic structure is the coronary sinus a derivative?
The L horn of the sinus venosus
What CN is assoc with the FIRST pharyngeal arch?
CN V
What CN is assoc with the SECOND pharyngeal arch?
CN VII
What CN is assoc with the THIRD pharyngeal arch?
CN IX
What CN is assoc with the FOURTH pharyngeal arch?
CN X
What CN is assoc with the FIFTH pharyngeal arch?
None, it degenerates
What CN is assoc with the SIXTH pharyngeal arch?
CN X
From where is the external auditory meatus derived?
First pharyngeal groove
From where is the smooth portion of the R atrium derived?
R horn of the sinus venosus
Meckel’s diverticulum is a remnant of what embryonic structure?
Vitelline duct (yolk sac)
Pons and cerebelum are derived from what portion of the embryonic neural tissue?
Metencephalon
The medulla is a derivative of what portion of the embryonic neural tissue?
Myelencephalon
What structure “tells” the overlying cells to begin neurulation?
Notochord
What structure splits the cloacal membrane, resulting in the formation of the perineum
Urorectal septum
In the adult, the thoracic veins are derived from what structure?
The cardinal veins
The GI tract and abdominal veins are derived from what structure?
VItelline veins
From what is the thyroid gland derived?
Floor of the endoderm (the posterior aspect of the tongue)
The thalamus and its related structures are derivatives of what?
The diencephalon
