Cardiovascular Development

Question 1

embryonic vascular systems

Answer 1

umbilical arteries and veins (placental)

vitelline arteries and veins

intraembryonic circulation with the cardinal system of veins

Question 2

three sequential systems of vein development

Answer 2

cardinal

subcardinal

supracardinal

Question 3

common cardinal veins

Answer 3

anterior cardinal - brachiocephalic vein, superior vena cava

posterior cardinal - pelvic and leg veins

Question 4

subcardinal system

Answer 4

becomes the middle IVC, renal, and gonadal veins

Question 5

supracardinal system

Answer 5

appears last

develops into azygous system and lower IVC

Question 6

vitelline system

Answer 6

forms intrahepatic inferior vena cava

hepatic veins

hepatic portal system

Question 7

components of the embryonic heart tube

Answer 7

endocardial tube

cardiac jelly

myocardial mantle

Question 8

development of the embryonic heart tube

Answer 8

starts out as left and right tubes that quickly fuse

the interior is shaped into a single sequence of chambers - sinus venosus, atrium, ventricle, bulbus cordis, truncus arteriosus

Question 9

partitioning of the heart tube

Answer 9

heart bends to the right in the middle of the ventricle, forming two ventricles in sequence

they are separated by a short and incomplete interventricular septum

blood flow is from the atrium to the left ventricle to the right ventricle

Question 10

dorsal mesocardium

Answer 10

a mesentary that surroudns the embryonic heart

Question 11

transverse pericardial sinus

Answer 11

a passage between the arteries and veins that forms once dorsal mesocardium breaks down

Question 12

endocardial cushions

Answer 12

dorsal and ventral structures that partition the A-V canal into left and right sides

Question 13

development of the IV septum

Answer 13

begins to grow from the floor of the ventricles toward the fused endocardial cushions

Question 14

septum primum

Answer 14

the primary septum that divides the atrium by growing down toward the endocardial cushions

forms the foramen primum

Question 15

septum secundum

Answer 15

forms the foramen secundum, which forms the framen ovale with the foramen primum

Question 16

When does the ventricular division become complete?

Answer 16

when the spiral septum, which partitions into the truncus arteriosus, fuses with the IV septum and the endocardial cushions

Question 17

What happens to the sinus venosus?

Answer 17

becomes the smooth part of the right atrium and the cornoary sinus

Question 18

What happens to the bulbus cordis?

Answer 18

becomes the smooth, outflow part of both ventricles, the conus arteriosus and aortic vestibule

Question 19

ductus arteriosus

Answer 19

a second fetal shunt between the pulmonary and systemic circulations

connects the pulmonary trunk to the aortic arch

there is little pulmonary blood flow until the first breath, when the vascular beds in the lung open with the first breath

becomes the ligamentum arteriosum a few weeks after birth

Question 20

ductus venosus

Answer 20

a fetal liver bypass

Question 21

changes at birth triggered by first breath

Answer 21

blood flows to lungs

left atrial pressure increases and closes the foramen ovale

oxygenated blood in the umbilical arteries causes smooth muscles to contract

umbilical veins collapse from lack of blood

ductus venosus becomes the fibrous ligamentum venosum

increased blood flow in left ventricle increases pressure int he aortic arch, decreasing blood flow through ductus arteriosus, allowing it to become the ligamentum arteriosum

Question 22

Tetralogy of Fallot

Answer 22

faulty spiral septum leading to:

pulmonary stenosis

IV septal defect

overriding aorta

right ventricular hypertrophy

Question 23

persistent truncus arteriosus

Answer 23

Complete communication between ascending aorta and aortic trunk

big time shunting of the blood to the pulmonary trunk

too much blood comes back to the heart

congestive heart failure develops

Question 24

transposition of the great arteries

Answer 24

spiral structure didn’t develop

blood flow to the heart is affected

huge interventricular septal defects

need to do surgery for the defect