Hae Q4 Heart Embryology

Front 1

prochordal plate

Back 1

-region at cephalic end of embryonic disc where ectoderm and endoderm remain in contact (migration of intra-embryonic mesoderm does not separate)
-replaced by the buccopharyngeal membrane (forms temporary seal of oral cavity and in week 4 breaks down to establish communication bt gut tube and amniotic cavity)

Front 2

sinus venosus

Back 2

-venous channel that drains blood into the heart from the embryo and the placenta
-initially symmetrical (2 horns)
-in adult it becomes the
1) coronary sinus
2) smooth part of right atrium, and
3) proximal portion of the IVC

Front 3

septum transversum

Back 3

unsegmented mesoderm
develops cranial to the prochordal plate
gives rise to:
-part of the diaphram
-the fibrous pericardium
-CT of the liver
migrates from position in cervical region of the embryo to the abdominal/thoracal portion of adult

Front 4

bulbus cordis

Back 4

part of heart tube that gives rise to:
-the conus cordis (outflow tract of ventricles) and the
-truncus arteriosus (which forms porximal parts of aorta and pulmonary trunk)

Front 5

conus cordis

Back 5

part of developing heart tube comprising outflow tracts, developed from the bulbus cordis and leading to the truncus arteriosus

Front 6

AV canal

Back 6

-communication between common atrium and the early ventricle
(initially positioned to the left side of developing heart, must shift to the middle)

Front 7

endocardial cushions

Back 7

-mesenchymal structures
-develop in the wall of the AV canal
-superior and inferior cushions on each side fuse to separate the AV canal into right and left openings
- the openings become the tricuspid and mitral valves respectively

Front 8

conotruncal cusions

Back 8

-form to separate the outflow tract of the heart (the trunkoconal region) into a pulmonary and aortic trunk
-derive from endothelial cells and neural crest cells that migrate into the cardiac jelly

Front 9

aorticopulmonary septum

Back 9

-spiral partition dividing the ascending aorta and the pulmonary trunk
- formed from the fusion of the conotruncal cushions (derived from endothelial and neural crest cells)

Front 10

cardiac jelly

Back 10

gelatinous noncellular material between the endothelial lining and the myocardial layer of the heart in very young embryos, later serving as a substratum for cardiac mesenchyme

Front 11

ductus venosus

Back 11

-embryonic vessel that lies on the visceral surface of the developing liver
-acts as a bypass thus enabling oxygenated blood in the umbilical vein to gain access to systemic circulation without passing through the liver

Front 12

ductus arteriosus

Back 12

embryonic vessel that connects the pulmonary trunk to the arch of the aorta (bypassing the lungs)

Front 13

septum secundum

Back 13

second crescent-shaped fold forming part of the developing atrial septum (the other part of the septum is made of the previously devloped septum primum)

Front 14

ostium secundum

Back 14

second foramen to form in the upper part of the septum primum which forms the foramen ovale of the atrial septum

Front 15

septum primum

Back 15

-sickle-shaped growth in the roof of the common atrium
-extends toward the endocardial cushions leaving the opening of the foramen primum

Front 16

foramen ovale

Back 16

hole in the atrial septum (left open after septum secundum forms as flap over most of the osteum secondum) in the embryo and fetus allowing oxygenated placental blood in the right side of the heart to pass to the left w/o going through the pulmonary circulation (normally this hole closes immediately after birth- forming fossa ovalis)

Front 17

membranous interventricular septum

Back 17

developed from endocardial cushions- makes up superior part of Interventricular septum

Front 18

heart forms at what rim of what structure?

Back 18

anterior trim of embryonic disk

Front 19

heart forms just (......) to the (......) plate

Back 19

rostral
prechordal plate

Front 20

angiogenic cell clusters

Back 20

develop around yolk sac in extraembryonic mesoderm, give rise to channels that extend into the embryo and form initial components of cardiovascular system

Front 21

from what structures are the embryonic paired heart tubes derived?

where in the embryo do the tubes initally form?

Back 21

-plexus of vascular channels, fuse to form endo thelially-lined heart tube
-surrounded by splanchnic mesoderm (future VISCERAL PERICARDUM)

-formed initally in the splanchnic/somatic mesoderm, bulge into the intraembryonic coelom

Front 22

what forms the pericardial cavity

Back 22

-formed by intraembryonic coelom
-initally this cavity is ventral to heart with a dorsal mesocardium suspending the heart
-eventually breaks down so the percardium surrounds the entire heart

Front 23

septum transversum- becomes what structure?

where is it found in relation to the developing heart?

Back 23

beomes the diaphragm
located just inferior to devloping heart

Front 24

when does the heart begin to beat?

Back 24

early in the 4th week of development

Front 25

flow of blood through primative "tube" sheart goes through what structures?

Back 25

-sinus venosus---
-pimative atria---
-the ventricles and bulbous cordis---
-then the aortic arch vessels---

Front 26

sinus venosus receives blood from what vessels?

Back 26

cardinal veins (drain embryo proper)
vitelline veins (from yolk sac and the umbilical veins from the placenta)

Front 27

cardinal veins

Back 27

drain embryo proper (drain into sinus venosus)

Front 28

vitelline veins

Back 28

drain yolk sac and umbilical veins from the placenta (transverse the liver and drain into sinus venosus)

Front 29

around day 23 venous end of embryonic heart tube folds in what direction relative to the ventricle?

what shape structure does the heart become?

Back 29

moves posterior and superior (folding up and over posteriorly to form atria)

heart tube becomes a loop

Front 30

what stucture is derived from the bulbus cordis?

Back 30

-becomes the conus cordis and acts as outflow tract for both ventricles to the truncus arteriosus

Front 31

bulbous cordis
fxn
name two parts

Back 31

outflow tract for the heart tube

conus cordis and truncus arteriosus

Front 32

where do the auricles come from?

Back 32

vestiges of the primative atria (rough-walled)
***definitive atria smooth walled, from incorporation of sinus venosus (on right) and the pulmonary veins (on left)

Front 33

definite aortic arch derived from

Back 33

the left 4th arch

Front 34

definitive ductus arteriosus derived from

Back 34

left 6th arch

Front 35

allows embryonic circulation to bypass the liver

Back 35

ductus venosus

Front 36

allows embryonic circulation to bypass the lungs

Back 36

ductus arteriosus
AND
foramen ovale

Front 37

what closes the foramen ovale in most cases?

Back 37

higher pressure in the LA due to increased venous return from lungs upon first breath

Front 38

what happens if foramen ovale does not close properly?

Back 38

forms left to right shunt between atria