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Question 1

what nad where is pectinate muscle found

Answer 1

parallel ridges in the atria wall

Question 2

what and where is crista temrinali found

Answer 2

vertical ridge of smooth myocardium in lateral aspect of right atrium of heart

Question 3

what and where is the fossa ovali

Answer 3

int he right atrium adn in fetus it connects right and left atrium in that direction

Question 4

what and where is the ligamentum arteriosum

Answer 4

small ligament attaching the pulmonary artery to the aorta

Question 5

what is the morula

Answer 5

16 IDENTICAL cells stage of cell division

Question 6

what dose the morula differntiate into

Answer 6

blastocsyt for implantatin

Question 7

what are the three germ layers that form our tissues

Answer 7

endoderm
mesoderm
ectoderm

Question 8

what does the endoderm differentiate into

Answer 8

gut and associated derived tissues (liver pancreas lungs)

Question 9

what does the mesoderm differentiate into

Answer 9

bones, CT, sleltal msucle, urogenital system, cardiovascular system

Question 10

what does the ectoderm differentiate into

Answer 10

skin CNS PNS eyes internal ear

Question 11

what is gastrulation

Answer 11

the formation of the three germ layers after implantation

Question 12

what is one of the earliest differentiating and functioning organ in a faetus

Answer 12

heart

Question 13

what germ layer does the heart arise form

Answer 13

cardiogenic mesoderm (aggregation of mesoderm

Question 14

what are blood islands

Answer 14

agrgegation of mesoderm

Question 15

what forms the endocardial heart tubes

Answer 15

blood islands (hemangioblasts specifically)

Question 16

how many endocardial heart tubes have we got

Answer 16

2

Question 17

where in relation to the embryo are the endocardial heart tubes located

Answer 17

ventral pole

Question 18

at what week of gestation are the endcardial heart tubes formed

Answer 18

by the middle of the third week

Question 19

by what process fo the endocardial heart tubes fuse into the primitive heart tube

Answer 19

lateral folding

Question 20

what do blood islands contain

Answer 20

hemangioblasts and myoblasts

Question 21

at what week of gestation do the endocardial heart tube fuse

Answer 21

21 days

Question 22

in what direction does blood flow thouhg the primitive heart tube

Answer 22

from venous side (down) to arterial side (up)

Question 23

what does the truncus arteriosus become

Answer 23

proximal aorta and pulmonary artery

Question 24

what does the bulbus cordis become

Answer 24

ventricular outlflow tracts and right ventricle

Question 25

what does the primitive ventricle become

Answer 25

left ventricle

Question 26

what does the primitive atria become

Answer 26

left and right atria

Question 27

what does the sinus venosus become

Answer 27

smooth part of right atrium and coronary sinus

Question 28

why does the heart fold instead of elongating

Answer 28

because limited by pericardium

Question 29

when does heart folding within the pericardium

Answer 29

between day 23 and 28

Question 30

in the folding process where do the ventricles and atria go

Answer 30

ventricles to the left | atria to the right

Question 31

pathology in which the heart is pointing to the right

Answer 31

dextrocardia | can be seen as part of situs inversus

Question 32

what structures are present in the heart on day 35

Answer 32

``` truncus arteriosus primitive atria primitive ventricle bulbus cordis sinus venosus ```

Question 33

in day 35 what links the primitive atria and primitive ventricle

Answer 33

atrioventricular canal

Question 34

what are endocardial cushions

Answer 34

two swellings of mesenchymal tissue appearing from wall of atrioventricular canal entre primitive atria and primitive ventricle

Question 35

at what gestational day do endocardial cushions form

Answer 35

day 28

Question 36

names of the two endocardial cushions

Answer 36

superior and inferior endocrdial cushions

Question 37

explain how the septum primum fomrms

Answer 37

septum starts to grow from atria toward the endocardial cushion (septum primium ) as it continues to grow vers endocardial cushion you have a gap entre endocardial cushiona nd septum called the ostium primum. As septum growsm the OP gets smaller. ​ Before OP can close completely, a second hole develops called the OS. OP is olbiterated but the OS stays. ​

Question 38

what two structures make up the atrial setptum

Answer 38

septum primum adn septum secundum

Question 39

explain how the septum primum fomrms

Answer 39

SS grows superiorly to inferiorly and this septum doesn’t grow as a complete sheath byt as a screcent shape. It always keeps a whole within it. The whole is the foramen ovale. ​ So atrial septum is made up of the OP and OS​ And the setpum primum creates a valve for foramen ovale. FO is not a hole but a valve that allwos flow entre the R and left atria in that direction. ​

Question 40

pathway of oxygenated blood in fetal

Answer 40

Oxygenated blood travels from hand side of the heart to foramen ovale to left atria to rest of the body​ Lungs have fluid so no point to send blood there​ Oxygenated blood comes from placenta to umbilicus through umbilical vein then toward liver ​ No point sending all blood all around liver so blood bypasses liver trough a shunt (ductus venosus) to the inferior vena cava. ​ IVC takes blood up to right artium then goes to LA but a small portion of it goes to RV and from there out via pulmonary trunk ​ ​ We odnt want too much blood going into th epulmonary areries twoard the lungs so you have naohter bypass called ductus arteriosus which allows blood to travel into descending aorta and travel around feuts; ​ ​ Deoxblood is reutrned to placenta via umblilca arteries. ​

Question 41

why is foramen ovale open at birth and closes after

Answer 41

Before birth, foramen ovale is open+jhigh pressure in r atria (due to fluid in lungs) the valve stays open​ At birth, lungs inflate w air so left hand side of the ehart has higher pressure, so valve closes.

Question 42

what is probe patent foramen ovale

Answer 42

when Valve of foramen ovale may not completely seal off in 25 % of people Defect usually small and is not clinically significant ebcause blood wont go from low pressure to high pressure environemnt anyway.

Question 43

atrial septal defect

Answer 43

you create a hole isntead of a valve and it cant close ASD incidence 7:10,000 births​ 2:1 prevalence in females versus males​ Septum primum and septum secundum defects This large ASD with left-to-right shunt resulted in pulmonary hypertension and increased pulmonary arterial pressures that led to right-to-left shunt, resulting in right ventricle hypertrophy

Question 44

explain process of ventricular septum formation

Answer 44

Muscular componnent grows vers endocardial cusion​ Membraneous component grow the other way ​

Question 45

what two components form the ventricular septum

Answer 45

muscular component and membranous component

Question 46

when does the interventricular septum develop

Answer 46

end of 4th week

Question 47

ventricular septal defect

Answer 47

Many small VSD will close spontaneously (30-50%). ​ Isolated VSD are detected with an incidence of 10-12:10,000. About 90% of VSD are in membranous septum and 10% in muscular septum.​

Question 48

most common type of cardiac defect

Answer 48

ventricular septal defect | 25%

Question 49

other name for aorticopulmonary septum

Answer 49

spiral septum

Question 50

where frmo does the spiral septum form

Answer 50

from the truncus arteriosus

Question 51

formation of spiral setum

Answer 51

Truncoconal swellings form in the truncus arteriosus and grow towards each other in a spiral structure​ Therefore the aorta connects with the left ventricle and the pulmonary trunk with the right ventricle​ ​

Question 52

when does spiral septum form

Answer 52

5th week​

Question 53

changes to ductus venosus form fetus to adult

Answer 53

fibroses to form ligamentum venosus​

Question 54

changes to foramen ovale form fetus to adult

Answer 54

closes because of increased pressure in LA (compared to RA) to form fossa ovalis

Question 55

changes to ductus arteriosus form fetus to adult

Answer 55

fibroses to form ligamentum arteriosum

Question 56

cyanotic heart lesions meaning

Answer 56

:bloos is shunted from right hand sie to left hand side of the heart​ Thers r to l shunting​ Deoxy blodo is taken around chld so child looks blue​

Question 57

acyanotic heart lesions meaning

Answer 57

a group of cardiac diseases with a Left-to-Right shunt or left heart abnormality which do not result in cyanosis (blue skin colour) of the baby.​ make up about one third of congenital heart disease

Question 58

example acyanotic heart lesions

Answer 58

ASD - Atrial Septal Defects​ VSD - Ventricular Septal Defects​ PDA - Patent Ductus Arteriosus​ Coarctation of the aorta

Question 59

patent ductus arteriosus

Answer 59

DA doesn’t fibrose so you have opening entre arch of aorta nd pulomonary trunk​ So blood goes from arch of aorta to ductus arteriosus to pulmonary trunk to the lungs carries a risk of endocarditis treatment is prostaglandin inhibitor like ibuprofen or surgical closue w clips in infants older than 3 months

Question 60

Coarctation of the aorta​

Answer 60

Defect where aorta is unusually narrowed. ​ This stenosis (narrowing) can be right before or after DA​ In preductal type the DA doesn’t clsoe because blood is pumped into arch of aorta and stuck​ high BP before point of coarctations low blood pressure beyond point of coarctation

Question 61

Examples of Cyanotic congenital heart disease are​

Answer 61

Tetralogy of Fallot​ Persistent truncus arteriosus​ Transposition of the great vessels

Question 62

tetralogy of fallot

Answer 62

comprises 4 defectrs Ventricular septal defect​ Overriding Aorta ​ aorta is positioned right over the top of the ventricular septal defect​ Pulmonary stenosis​ Right ventricular hypertrophy​

Question 63

Persistent Truncus Arteriosus​

Answer 63

Single artery (truncus) arises from the heart, supplying both aorta and pulmonary artery.​ ​ A large VSD (ventricular septal defect) below the truncal valve allows mixing of right and left ventricular blood​ ​ Degree of cyanosis is variable​ ​ Presents with progressive heart failure​ ​ ​

Question 64

Transposition of the Great Vessels​

Answer 64

Conotruncal septum fails to follow spiral course (runs straight down)​ ​ Usually accompanied by open ductus arteriosus​ ​ Blue baby – immediate surgical intervention – catherterisation of fossa ovalis to increase mixing of pulmonary and systemic blood– buy time till infant can be operated on at later date​