Embryology of the cardiovascular system Flashcards by Rachel Hughes

What tissue forms the circulatory system?

Lateral plate splanchnic mesoderm

How well did you know this?

Not at all

Perfectly

What does the lateral plate mesoderm spit into?

Somatic mesoderm - forms body wall structures e.g. bone, muscle
Splanchnic mesoderm - forms organs

How well did you know this?

Not at all

Perfectly

When do the angioblastic cords first appear in the cardiogenic mesoderm?

3rd week of development

How well did you know this?

Not at all

Perfectly

What tissue make up the two layers of the pericardium?

Parietal layer of serous and fibrous pericardium = somatic mesoderm

Visceral layer of serous pericardium = splanchnic mesoderm

How well did you know this?

Not at all

Perfectly

What makes up the caudal end of the fused primitive heart tube?

Sinus venosus

Atrium

How well did you know this?

Not at all

Perfectly

What makes up the cranial end of the fused primitive heart tube?

Ventricle
Bulbus cordis
Truncus arteriosus

How well did you know this?

Not at all

Perfectly

What vein is responsible for the yolk sac?

Vitelline vein

How well did you know this?

Not at all

Perfectly

What vein is responsible for the placenta?

Umbilical vein

How well did you know this?

Not at all

Perfectly

What vein is responsible for the body of the embryo?

Common cardinal vein

How well did you know this?

Not at all

Perfectly

How many pairs of aortic arches are there from the trunks arteriosus?

6 pairs

How well did you know this?

Not at all

Perfectly

How does looping occur with the primitive heart tube?

Bulbus cordis and ventricle grow faster than other regions, growing heavy and pulling these down to form a U-shaped bulboventricular loop

How well did you know this?

Not at all

Perfectly

What is dextrocardia?

Heart loops to the LEFT instead of the right, thus the heart lies to the right side of the body

How well did you know this?

Not at all

Perfectly

What is the most common position abnormality of the heart?

Dextrocardia

How well did you know this?

Not at all

Perfectly

When does partitioning of the primordial heart occur?

27th-37th days of embryonic development

How well did you know this?

Not at all

Perfectly

What does endocardial cushion formation cause?

Separation of the right and left atrioventricular openings

How well did you know this?

Not at all

Perfectly

What does septum formation cause?

Separates right atrium from left atrium and right ventricle from left ventricle

How well did you know this?

Not at all

Perfectly

When does the septum primum develop?

End of 4th week, forming the foramen primum between the septum primum and the endocardial cushion

How well did you know this?

Not at all

Perfectly

What leads to the development of the formamen secondum?

Apoptosis induced perforation of the septum primum causes part of it to break off and float towards the endocardial cushion, forming two foramen either side, before the fragment eventually fuses to the cushion, leaving the foramen secondum

How well did you know this?

Not at all

Perfectly

To which side of the septum primum does the septum secondum develop?

Right

How well did you know this?

Not at all

Perfectly

When does the septum secondum develop?

5th and 6th week of development

How well did you know this?

Not at all

Perfectly

Describe the formation of the foramen ovale

Septum secondum grows and slightly overlaps septum primum, but leaves a incomplete partition allowing the flow of blood from the right atrium to the left atrium in the embryo

How well did you know this?

Not at all

Perfectly

What causes the foramen ovale to close and form the fossa ovalis after birth?

Increased pulmonary blood flow and shift of pressure to the left atrium

How well did you know this?

Not at all

Perfectly

What condition is associated with the non-closure of the foramen ovalis?

Atrial septal defect (ASD), “hole in the heart”

How well did you know this?

Not at all

Perfectly

Describe the 4 main clinically significant types of ASD

Foramen secondum defect
Endocardial cushion + septum primum defect
Sinus venous defect
Common atrium

How well did you know this?

Not at all

Perfectly

What are the two most common types of ASD

Foramen secondum defect | Endocardial cushion + septum primum defect

Why are females more prone to ASD?

Tend to develop more quickly, meaning more likely for mistakes to occur

Describe the partitioning of the bulbs corgis and trunks arteriosus

5th week Neural crests in walls of both proliferate Ridges form between each These undergo 180 degree spiralling to form the aorticopulmonary (conotruncal) septum

Describe the separation of the primordial ventricles

Muscular ventricular septum forms Interventricular foramen left Aorticopulmonary septum forms and fuses with the muscular ventricular septum, closing the interventricular septum Endocardial cushion grows and separates the atria from the ventricles

What is the most common type of congenital heart disease?

Ventricular septal defect (25% of cases)

What is the cause of cot death or sudden infant death syndrome?

Abnormalities of the conduction system of the heart

What primordial heart tubes makes up the right atrium?

Sinus venosus

What part of the adult heart is made up from the primitive atrium?

Parts of the left and right atrium

What primordial heart tubes makes up the left ventricle?

Primitive ventricle

What primordial heart tubes makes up the right ventricle?

Bulbus cordis

Name some common causes of congenital heart disease

``` Rubella infection in pregnancy (PDA) Maternal alcohol abuse (septal defects) Drug use and radiation Genetic Chromosomal ```

What is a common cause of cyanotic disease in newborns?

Transposition of the great vessels, usually associated with ASD and VSD

What 4 defects make up tetralogy of fallot?

Pulmonary stenosis VSD Dextroposition of the aorta Right ventricular hypertrophy

What are some signs of tetralogy of fallot?

``` Blue Tet spells Murmur Finger clubbing Tire during breastfeeding ```

Whats the difference between vasculogenesis and angiogenesis?

V - formation of new network of vessels | A - growth of new vessels from existing blood vessels

What are the first arteries to appear in the embryo?

Right and left aortae

Whats the fate of the 1st and 2nd aortic arch?

Maxillary arteries (1st), 2nd disappears

What is the fate of the 3rd aortic arch?

common and internal carotid artery (and therefore the carotid arch)

What is the fate of the 4th aortic arch?

Left side - arch of aorta | Right side - right subclavian artery

What is the fate of the 5th aortic arch?

Never forms completely and regresses

What is the fate of the 6th aortic arch?

Right pulmonary artery from proximal right arch | Left pulmonary artery and ductus arteriosus from left arch

What is the ductus arteriosus?

Blood vessels that connects the pulmonary artery to the proximal descending aorta, which normally closes to form the ligamentum arteriosum within 1-3 months following birth

Describe the clinical effects aberrant subclavian artery

3rd branch of ascending aorta is abnormally found on the left side, meaning it has to loop back over the trachea and oesophagus to supply the right arm, which can be constricted although usually there are no clinical signs

Describe the clinical effects of a double aortic arch

Abnormal right and left aortic arch, forming a ring around the trachea and oesophagus, which can cause difficulty when swallowing and breathing

What are the signs of patent ductus arteriosus?

Increased effort in breathing Poor weight gain in first year of life Can lead to congestive HF if not found

Where is coarctation of the aorta most common?

Aortic arch

What arteries supply the yolk sac?

Vitelline arteries

What arteries supply the placenta?

Umbilical arteries

Describe the fate of the vitelline arteries

Form major arteries of the gut: - celiac artery - foregut - superior mesenteric artery - midgut - inferior mesenteric artery - hindgut

Describe the fate of the umbilical arteries

Proximal portion persists as internal iliac and superior vertical branches to bladder Distal portion degenerates and forms medial umbilical ligaments

Describe the fate of the cardinal veins

Become major vessels of the liver: - portal vein - hepatocardiac part of IVC - liver sinusoids - superior mesenteric vein

Describe the fate of the umbilical veins

Right - degenerates completely Left - degenerates and forms ligamentum trees hepatis Ductus venosus - obliterates and forms ligamentum venous

What is the ductus venosus?

Shunts blood from left umbilical vein to the inferior vena cava, allowing oxygenated blood from the placenta to bypass the liver

Describe the initial development of the lymphatic system

End of 6th week, develop around main veins | Six primary lymph sacs develop at end of embryonic period and fuse with vessels later on

Who are more likely to develop patent ductus arteriosus?

Females Maternal rubella infection Premature babies

What causes patent ductus arteriosus?

Failure of muscular wall to contract Respiratory distress syndrome Lack of surfactant in lungs

What reasons do people think cause coarctation of the aorta alongside ductus arteriosus?

Incorporation of muscle tissue from DA into aortic arch, so when DA contracts with birth, it also constricts the aorta Genetic/environmental factors