Cardiovascular System

Front 1

When does the primordial heart and the vascular system appear?

Back 1

middle of the third week

Front 2

why does the embryo need heart and vascular to appear

Back 2

because the embryo is no longer able to satisfy its nutritional requirements by diffusion alone

Front 3

what is the cardiovascular system derived from

Back 3

splanchnic mesenchyme

paracxial and lateral plate mesoderm

neural crest cells

Front 4

what is the splanchnic mesenchyme

Back 4

the primordium of the heart

Front 5

what does the lateral plate mesoderm split into?

Back 5

somatic layer and splanchnic layer

Front 6

when the later plate mesoderm splits into the somatic layer and the splanchnic layer, it forms what?

Back 6

the pericardial cavity

Front 7

the pericardic mesoderm is distributed in the splanchnic layer and is now called?

Back 7

heart-forming regions (HFRs)

Front 8

the HFRs fuse in the midline to form what?

Back 8

a continuous sheet of mesoderm

Front 9

the hypertrophied foregut endoderm induces through what?

forming what?

Back 9

vascular endothelial growth factor (VEGF)

a single endocardial tube or heart tube (endocardium)

Front 10

when do the angioblast cords appear

Back 10

day 18

Front 11

what are angioblastic cords?

Back 11

paired endothelial strands of cariogenic mesoderm that are the primordial of the heart

Front 12

the angioblastic cords fuse to form what?

Back 12

heart tube

Front 13

the heart begins to beat at?

Back 13

22-23 days

Front 14

the blood flow begins at?

Back 14

week 4

Front 15

molecular studies in mouse and chick embryos have shown what?

Back 15

presence of two 6HLH (basic helix loop helix) genes, dHAND and eHAND, in the paired primordial endocardial tubes and in later stages of morphogenesis

Front 16

what is an essential regulator in early cardiac development before the formation of heart tubes

Back 16

murine gener MEF2C

Front 17

in the primitive heart tube, the venous blood flows through what first

Back 17

L ventricle

Front 18

what is the correction event so that the heart is able to get the venous blood flow into the R ventricle

Back 18

dextral looping

Front 19

what are the 4 dilations along the length of the heart tube

Back 19

truncus arteriosus

bulbus cordis

primitive ventricle

primitive atrium

sinus venosus

Front 20

in dextral looping, the primitive heart rotates to which side?

Back 20

R

Front 21

what does dextral looping overall do

Back 21

correct the venous flow and proper alignment of the atrioventricular canal and the conoventricular canal

Front 22

regarding the heart, what is it status on day 26

Back 22

it has its five dilations and has started the process of dextral-looping

Front 23

what is the precursor of endocardium

Back 23

endothelial lining of the heart

Front 24

once the heart tube is fused, the primordial myocardium is formed from?

Back 24

splanchnic mesoderm surrounding the pericardial coelom

Front 25

what is the epicardium/visceral pericardium derives from

Back 25

mesothelial cells and arise from the sinus venous and spread over the myocardium

Front 26

where do the bulbar and the trancal ridges derive from?

Back 26

mesenchymal cells of the bulbs cordis

Front 27

where are the bulbs cords derived from

Back 27

neural crest cells

Front 28

how do the neural crest cells reach the ridges when partitioning of the bulbus cords and trunks arteriosus

Back 28

they migrate through the pharynx and the pharyngeal arches

Front 29

after the bulbar and truncal ridges reach the ridges what happens?

Back 29

they undergo a 180 degree spiraling

Front 30

when does the aorticopulmonary or AP septum forms?

Back 30

when the tranquil and bulbar ridges fuse

Front 31

what happens when the tranquil and bulbar ridges fuse

Back 31

the AP / aorticopulmonary septum is made

Front 32

what does the AP septum do?

Back 32

divides truncus arteriosus and bulbus cordis into the aorta and pulmonary trunk

Front 33

what is it called when there is just a partial development of the AP septum

Back 33

persistent truncus arteriosus (PTA)

Front 34

what is the result of PTA?

Back 34

one large vessel leaving and receiving blood from both the R and L ventricles

Front 35

what does PTA also present with?

Back 35

membranous ventricular septum defect

Front 36

when the newborn is born with PTA, are they cyanotic or not?

Back 36

severely cyanotic

Front 37

PTA has what direction of shunting?

Back 37

R to L

Front 38

with the tetralogy of fallot (TF) what is happens

Back 38

Pulmonary stenosis

RVH

Oveririding aorta

VSD

Front 39

what causes TF?

Back 39

abnormal neural crest cell migration

Front 40

TF results in what?

Back 40

pulmonary trunk with a small diameter, and aorta with large diameter

Front 41

TF is associated clinically with?

Back 41

marked cyanosis

(R to L shunting)

Front 42

can the baby survive TF?

Back 42

maybe, depends on severity of pulmonary stenosis

Front 43

what happens with D-transposition of the great arteries

Back 43

aorta arises form R ventricle

pulmonary trunk from L ventricle

--> resulting in separated systemic circulations

Front 44

D-transposition of the great arteries is incompatible with life unless there is

Back 44

a VSD, patent foramen oval, or a patent ductus arteriosus

Front 45

with D-transposition of the great arteries, what happens with the newborn

Back 45

they are cyanotic (r to l shunt)

Front 46

this happens when the aorta and pulmonary trunk are transposed and the ventricles are inverted such that the anatomical r ventricle lies on l side and the l ventricle lies on the r side

Back 46

L-transposition

Front 47

with L-transposition, is the blood flow normal

Back 47

yes

Front 48

what is the trunk arteriosus (TA) continuous with cranially from where the arch arteries arise

Back 48

aortic sac

Front 49

what are the arterial and venous ends of the heart fixed by?

Back 49

pharyngeal arches and septum transversum

Front 50

as the heart elongates and bends, it invaginates in what?

Back 50

pericardial cavity

Front 51

the heart is suspended from the dorsal wall by what?

Back 51

dorsal mesocardium

Front 52

what is the transverse pericardial sinus made of

Back 52

the dengerneation of the central part of the dorsal mesocardium

Front 53

what does the septum primum form

Back 53

roof of the primitive atrium and it grows toward the AV cushions in the AV canal

Front 54

the foramen premium forms between what?

Back 54

septum primum and AV cushions

Front 55

when does the foramen primum close

Back 55

when the septum primum fuses with the AV cushions

Front 56

where does the septum secdundum form in relation to the septum primum

Back 56

to the R

Front 57

what is the foramen ovale

Back 57

the opening between the upper and lower limbs of the septum secundum

Front 58

what is the purpose of the foramen ovale

Back 58

blood is being shunted from the R atrium to the L atrium through this

Front 59

after birth, how is the foramen ovale closed

Back 59

decrease in R atrial pressure

increase in L atrial pressure

Front 60

what is the most clinically significant atrial septum defect

Back 60

foramen secundum defect

Front 61

what cause foramen scandium defect

Back 61

excessive resorption of septum primum, septum scandium or both

Front 62

what does the foramen scandium defect result in

Back 62

R and L atria opening

Front 63

what is another name for common atrium

Back 63

cor triloculare

Front 64

what is common atrium

Back 64

condition where there is formation of only one atrium

Front 65

what is the closure of the foramen oval during prenatal life

Back 65

premature closure of foramen ovale

Front 66

what does the premature closure of the foramen oval result in?

Back 66

hypertrophy of the R side of the heart and underdevelopment of the L side of the heart

Front 67

this is due to the abnormal resorption of the septum primum during formation of the foramen secundum

Back 67

patent oval foramen

Front 68

if resorption occurs in abnormal locations, what happens?

Back 68

septum primum is fenestrated or netlike

Front 69

if there is an abnormally large oval foramen b/c of defective development of septum secundum, what happens?

Back 69

a nl septum will not close the abnormal oval foramen at birth

Front 70

what partitions the AV canal in the R and L AV canals

Back 70

atrioventricular septum

(AV septum)

Front 71

how is the AV septum made

Back 71

dorsal AV cushion and the ventral AV cushion fuse

Front 72

how is a persistent common AV canal caused

Back 72

by the failure of fusion of the AV cushions

Front 73

what AV septum defects and the persistent common AV canal, what can be found in the center of the heart

Back 73

large hole

Front 74

with the persistent common AV canal, what happens with the tricuspid and bicuspid canals

Back 74

they result in one valve common to both sides of the heart

Front 75

this is caused by the failure of the posterior and septal leaflets of the tricuspid valve to attach normally to the annulus fibrosus, so they end up displaced inferiorly into the R ventricle

Back 75

Ebstein's anomaly

Front 76

with the ebstein's anomaly, the R ventricle is divided into what?

Back 76

upper "atrialized" portion and a small, lower functional portion

Front 77

with ebsteins anomaly, the R atrium enlarges why?

Back 77

blood backs up into the R atrium

Front 78

another name for tricuspid atresia

Back 78

hypoplastic R heart

Front 79

with this, there is complete agenesis of the tricuspid valve so the there is no communication between the R atrium and R ventricle

Back 79

tricuspid atresia

Front 80

with tricuspid atresia, is there cyanosis?

Back 80

yes

Front 81

with tricuspid atresia, this is always associated too

Back 81

a patent foramen ovale, septum defect, overdeveloped L ventricle and underdeveloped R ventricle

Front 82

these are the cyanotic congenital diseases of a newborn

Back 82

VSD, patent ductus arteriosus, artial septal defect

Front 83

these cause outflow obstruction

Back 83

pulmonary stenosis, aortic stenosis, correction of the aorta

Front 84

are the outflow obstruction diseases cyanotic or acyanotic?

Back 84

acyanotic

Front 85

These are cyanotic diseases

Back 85

tetralogy of fallot

transposition of the great arteries

complete AV septal defect

Front 86

when the IV foramen is closed by the membranous IV septum, this forms the proliferation and fusion by these three sources

Back 86

right bulbar ridge, left bulbar ridge, and the AV cushions

Front 87

the muscular IV septum develops in the midline on floor of the primitive ventricle and grows toward what

Back 87

fused AV cushions

Front 88

this is the most common type of VSD

Back 88

membranous VSD

Front 89

what happens in membranous VSD

Back 89

there is a faulty fusion of the R bulbar ridge, L bulbar ridge, and the AV cushions

Front 90

with the faulty fusion on the membranous VSD, what happens?

Back 90

the opening allows for free flow of blood

Front 91

what does a large VSD present with

Back 91

L to R shunting of blood, increased pulmonary blood flow, and pulmonary HTN

Front 92

a secondary effect of the Large VSD and pulmonary HTN is what?

Back 92

thickening of the tunica media of the arteries and arterioles, resulting in narrowing of lumen

Front 93

with the pulmonary resistance causing the R to L shunting of blood and cyanosis, this stage of membranous VSD is now called?

Back 93

eisenmenger complex

Front 94

muscular VSD causes

Back 94

single or multiple perforations in the muscular IV septum

Front 95

common ventricle (for triloculare biatriatum) cause

Back 95

failure of the membranous and muscular IV septa to form