Anatomy Embryo Flashcards
Sinus venosus forms ___
Smooth walled portion of right atrium
Coronary sinus
Bulbus cordis forms ___
Right ventricle
Conus arteriosus forms ___
Left and right ventricle
Truncus arteriosus forms ____
Splits to form ascending aorta and pulmonary a.
The heart begins to loop on day ___
23
The septa first originate as bulges and ridges, called ___
Cushion tissues
At the end of week ___ the endocardial cushions develop on the walls of the AV canal, separating it into left and right
4
The septum primum grows from the ___ and separates the ___. It fuses to the ___ and the foramen primum becomes closed
Roof of the primordial atrium
Left and right atria
AV septum
The foramen secundum allows __
Shunting of blood from right atrium to left
The foramen ovale is an opening left in the ___
Septum secundum
The valve of the foramen ovale is formed from the ___
What does it do?
Caudal part of the valve of the foramen ovale (from the septum primum)
*prevents left to right shunting of blood
The ___ regresses and later becomes the coronary sinus
Left sinus horn
The ___ enlarged and becomes incorporated in the right atrium, forming the smooth walled portion
Right sinus horn
The ___ becomes incorporated into the left atrium wall forming the smooth walled portion
Primordial pulmonary v.
The ___ forms the muscular interventricular septum
Bulboventricular sulcus
The separation of the truncus arteriosus and the bulbus cordis forms the ___
Pulmonary trunk and aorta
Due to the formation of the aorticopulmonary septum (spiral septum) which turns 180 degrees towards the interventricular septum
The most common congenital cardiac malformation
Ventricular septal defect
Leaves a large opening between the atria
Due to excessive resorption of septum priming or inadequate development of septum secundum
Ostium secundum defect
Complete absence of atrial septum
Can produce cyanosis in rare cases
Cor triloculare biventriculare
Caused by the fusion of the cusps of the aortic valve
Aortic stenosis
Due to unequal division of the conus became de of displacement of the spiral septum.
Tetralogy of fallot
4 alterations present in the tetralogy of fallot
- Pulmonary infundibular stenosis
- Large IV septal defect
- Overriding aorta directly above the septal defect
- RVH
Occurs when the spiral septum fails to follow the spiral course and instead runs straight down. This causes the aorta to originate from the right ventricle instead of the left and the pulmonary a. to originate from the left ventricle instead of the right.
This is usually accompanied by ___
Transposition of the great vessels
An open ductus arteriosus
Failure of fusion of the bulbar and truncal ridges, always accompanied by a defective IV septum. This undivided truncus thus receives blood from both sides of the heart
Persistent truncus arteriosus
Cyanotic congenital heart malformation in which the left ventricle is underdeveloped. Typically there is a large patent foramen ovale, a patent ductus arteriosus, and hypoplastic ascending aorta/aortic arch and mitral/aortic valves
Hypoplastic left heart syndrome
The formation of new blood vessels through the differentiation of angioblasts.
*larger blood vessels are formed this way
Vasculogenesis
The formation of new blood vessels through budding and sprouting from existing vessels
*smaller vessels are made this way
Angiogenesis
The ___ form the primary outflow vessels of the heart
Dorsal aortae
- The ___ arch forms the stapedial artery
- The ___ arch forms the left and right CCAs
- The ____ arch becomes the external carotid and maxillary arteries
2nd
3rd
1st
Fate of the 4th arch
- right: proximal right subclavian
- left: ascending aorta (aortic arch)
The fate of the 6th arch:
Becomes continuous with the pulmonary trunk
- forms pulmonary arteries on the right
- forms ductus arteriosus on the left
The ductus arteriosus connects to the ____ and allows ___. It is closed at birth and later forms the ___
Aorta
Shunting of blood from the pulmonary trunk to the descending aorta
Ligamentum arteriosum
3 major arteries that come from vitelline arteries:
- Celiac: most superior, supplies foregut
- SMA: midgut
- IMA: hindgut
Lateral branches of the descending aorta supply ___
Adrenal glands
Gonads (descend)
Kidneys (ascend)
Intersegmental branches of the aorta arise from the ___ surface and supply ___
Posterolateral
Somite derivatives
- dorsal branches supply neural tube, deep back muscles, and dorsal skin
- ventral become intercostal, lumbar, and lateral sacral arteries
Arteries of the limbs are formed by ___
Remodeling of the intersegmental arteries
Umbilical arteries are initially branches of the ____ but during 4th week of development they shift their origin to the ____
Dorsal aorta
Internal iliac arteries
Divisions of the primitive embryonic venous system
Vitelline
Umbilical
Cardinal
Vitelline veins arise from the ____ and carry blood from ___
Capillary plexuses in the yolk sac
From the yolk sac to the sinus venosus
The ___ become hepatic sinusoids , the IVC, portal v., and SMV
Vitelline veins
Umbilical veins (2) originate in the \_\_\_\_ and carry \_\_\_ *what happens during the 2nd month?
Chorionic villa
Oxygenated blood to the embryo
*right umbilical v. becomes obliterated
The connection between the left umbilical v. and the IVC
Ductus venosus
*shunts oxygenated blood from the umbilical system to IVC and right atrium allowing bypass of the portal system of the liver
___ veins drain the body of the embryo
Cardinal
The left brachiocephalic v. is formed from what?
Anterior cardinal veins become connected, which shunts blood from left to right. This anastomotic shunt becomes the left brachiocephalic v.
The ___ form the SVC
Right anterior cardinal v. And right common cardinal v.
___ veins drain the kidneys and develop medial to the posterior cardinal veins
Subcardinal
The ___ replace the posterior cardinal veins in draining the posterior part of the body wall. It becomes what?
Supracardinal veins
- right becomes azygous
- left becomes hemiazygous
The IVC is formed by the fusion of what?
- Hepatic (from right vitelline)
- Renal (from right subcardinal)
- Postrenal (right supracardinal)
- Sacral (right and left posterior cardinal)
In the ___ oxygenated and deoxygenated blood from the body mixes. The mixed blood enters the ___, then what happens?
IVC
Right atrium
Most blood shunts to left atrium via foramen ovale. Some remains, mixing with deoxygenated blood from SVC ( which drains head and upper limbs)
From the left atrium, blood flows where?
To left ventricle and into aorta.
Blood from the SVC enters the ___
Right atrium then goes to right ventricle then pulmonary trunk
Most blood in the pulmonary trunk passes through the ___ into the ___ where it mixes with blood from the ascending aorta, bypassing the lungs
Ductus arteriosus
descending aorta
