Embryology of the CVS 2

Question 1

What are the 2 methods that blood vessels develop by?

Answer 1

Vasculogenesis

Angiogenesis

Question 2

What is vasculogenesis?

Answer 2

New formation of a primitive vascular network

Question 3

What is the new formation of a primitive vascular network called?

Answer 3

Vasculogenesis

Question 4

What is angiogenesis?

Answer 4

The growth of new vessels from pre-existing blood vessels

Question 5

What is the growth of new vessels from pre-existing blood vessels called?

Answer 5

Angiogenesis

Question 6

What is the process of the formation of the aortic sac?

Answer 6

1) First arteries to appear in the embryo are the left and right primitive aortae
2) Each primitive aorta has a ventral part (ventral aorta) and a dorsal part (dorsal aorta)
3) After the fusion on the two endothelial tubes the two ventral aortae partially fuse to form aortic sac
4) Aortic branches arise from the aortic sac

Question 7

What are the first arteries to appear in the embryo?

Answer 7

Left and right primitive aorta

Question 8

What is the process of the development of the pharyngael arch arteries and aortic branches?

Answer 8

1) Pharyngeal arches (future neck) develop during 4th and 5th week
2) Each arch receives its own nerve and artery (pharyngael arteries)
3) Pharyngael arteries communicate with aortic branches (now called aortic arches)
4) 6 aortic arches are formed on each side, all in communication with the dorsal aortae

Question 9

When does the pharyngael arches develop?

Answer 9

During 4th and 5th week

Question 10

How many pairs are present in the aortic arches?

Answer 10

6 pairs

Question 11

What do the 6 pairs of the aortic arches develop from?

Answer 11

Aortic branches and pharyngael arteries

Question 12

What should be noted about the aortic arches and how long they are present for?

Answer 12

They are not all present at the same time

Question 13

Where do all of the aortic arches terminate?

Answer 13

Dorsal aorta

Question 14

What is the fate of aortic arch 1 and 2?

Answer 14

Disappear early, remnant of the 1st arch forms part of the maxilary artery

Question 15

What is the fate of aortic arch 3?

Answer 15

Common carotid and commencement of the internal carotid artery (so is named carotid arch)

Question 16

What is the fate of aortic arch 4?

Answer 16

4th right arch forms the right subclavian

4th left arch constitutes the distal part of aortic arch

Question 17

What is the fate of the 5th aortic arch?

Answer 17

Never forms or forms incompletely and then regresses

Question 18

What is the fate of the 6th aortic arch?

Answer 18

Proximal part of the 6th right arch persists as the proximal part of the right pulmonary artery

6th left arch gives of the left pulmonary artery and forms the ductus arteriosus, within 1-3 months the ductus is obliterated and becomes the ligamentum anteriosum

Question 19

What does the ductus arteriosus become once it is obliterated?

Answer 19

Ligamentum arteriosum

Question 20

What are the maxillary arteries derived from?

Answer 20

Aortic arch 1

Question 21

What is the common carotid and first part of internal carotid artery derived from?

Answer 21

Aortic arch 3

Question 22

What is the arch of aorta (distal portion) derived from?o

Answer 22

Aortic arch 4 left side

Question 23

What is the right subclavian artery (proximal portion) derived from?

Answer 23

Aortic arch 4 right side

Question 24

What is the left pulmonary artery and ductus arteriosus derived from?

Answer 24

Aortic arch 6 left side

Question 25

What is the right pulmonary artery derived from?

Answer 25

Aortic arch 6 right side

Question 26

What do most defects of the great arteries arise due to?

Answer 26

Persistance of aortic arches that normally should regress or regression of arches that normally shouldn't

Question 27

What are examples of defects of the great arteries due to aortic arches not regressing or regressing when they shouldn't?

Answer 27

Aberrant subclavian artery Double aortic arch Patent ductus arteriosus (PDA) Coarctation of the aorta

Question 28

What is aberrant subclavian artery?

Answer 28

With regression of the right aortic arch 4 and the right dorsal aorta the right subclavian artery has an abnormal origin on the left side, meaning to supply blood to the right arm this forces the right subclavian artery to cross the midline behind the trachea and oesophagus which may constrict these organs

Question 29

What is double aortic arch?

Answer 29

Occurs with the development of an abnormal right aortic arch in addition to the left aortic arch, forming a ring around the trachea and oesophagus which usually causes difficulty swallowing and breathing

Question 30

What is patent ductus arteriosus (PDA)?

Answer 30

Ductus arteriosus fails to close after birth Early symptoms are common but in the first year of life include increased work of breathing and poor wait gain Uncorrected PDA may lead to congestive heart failure with increasing age

Question 31

What does PDA stand up for?

Answer 31

Patent ductus arteriosus

Question 32

What are symptoms of patent ductus arteriosus (PDA) in the first year of life?

Answer 32

Increased work of breathing Poor weight gain

Question 33

What could patent ductus arteriosus lead to in later life?

Answer 33

Congestive heart failure

Question 34

What is coarctation of the aorta?

Answer 34

Aorta is narrow, usually in the area where the ductus arteriosus (ligamentum arteriosum after regression) inserts

Question 35

What are the 2 kinds of coarctation of the aorta?

Answer 35

Preductal (proximal to ductus arteriosus) Post ductal (distal to ductus arteriosus)

Question 36

What supplies the yolk sac with blood?

Answer 36

Vitelline vein and artery

Question 37

What supplies the placenta with blood?

Answer 37

Umbilical artery and vein

Question 38

What supplies the rest of the embryonic body with blood?

Answer 38

Cardinal artery and vein

Question 39

What does the vitelline arteries and veins supply?

Answer 39

Yolk sac

Question 40

What does the umbilical arteries and veins supply?

Answer 40

Placenta

Question 41

What does the cardinal arteries and veins supply?

Answer 41

The rest of the body

Question 42

What is the fate of the vitelline arteries after birth?

Answer 42

Represented by arteries to the foregut, midgut and hindgut

Question 43

What is the fate is the fate of the umbilical arteries after birth?

Answer 43

Proximal portion persists as internal iliac and superior vesical branches to urinary bladder

Question 44

What is the embryonic venous system composed of?

Answer 44

Vitelline veins Umbilical veins Cardinal veins

Question 45

What do the vitelline veins do?

Answer 45

Carry blood from the yolk sac to the sinus venosus

Question 46

What do the umbilical veins do?

Answer 46

Originate from chorionic villi of placenta carrying oxygenated blood to the embryo

Question 47

What do the cardinal veins do?

Answer 47

Drain the body of the embryo

Question 48

What veins drain the body of the embryo?

Answer 48

Cardinal veins

Question 49

What supplies the embryo with oxygenated blood from the chorionic villi of the placenta?

Answer 49

Umbilical veins

Question 50

What vein carries blood from the yolk sac to the sinus venosus?

Answer 50

Vitelline veins

Question 51

What is the fate of the cardinal veins?

Answer 51

Form vena caval system by anastomosis amoung the veins

Question 52

What is the main venous system of the embryo composed of?

Answer 52

Anterior cardinal veins Posterior cardinal veins Common cardinal vein all draining to sinus venosus

Question 53

What is anastomosis?

Answer 53

Corss connections between adjacent channels

Question 54

What are cross connections between adjacent channels called?

Answer 54

Anastomosis

Question 55

What are examples of venous system abnormalities?

Answer 55

Double IVC Absence of IVC Left SVC Double SVC

Question 56

What does IVC stand up for?

Answer 56

Inferior vena cava

Question 57

What does SVC stand up for?

Answer 57

Superior vena cava

Question 58

When does the lymphatic system develop?

Answer 58

End of the 6th week

Question 59

What does the lymphatic system develop around?

Answer 59

Main veins

Question 60

In terms of lymphatics, what develops at the end of the embryonic period?

Answer 60

Six primary lymph sacs

Question 61

What are some of the lymph sacs that develop at the end of the embryonic period?

Answer 61

Jugular lymph sac Retroperitoneal lymph sac Cisterna chyli Iliac lymph sac

Question 62

What is good respiration in neonate dependent upon?

Answer 62

Normal circulatory transition at birth (placental circulation to pulmonary circulation)

Question 63

What circulation transition occurs at birth?

Answer 63

Placental circulation to pulmonary circulation

Question 64

What are important vascular structures in the transitional circulation?

Answer 64

Ductus venosus (shunts left umbilical vein blood flow directly to inferior vena cava allowing oxygenated blood from the placenta to bypass the liver) Oval foramen (allows blood to enter the left atrium from the right atrium, allowing it to bypass the lungs) Ductus arteriosus (allows blood that still escapes to the right ventricle to bypass the lungs)

Question 65

What does the ductus venosus allow?

Answer 65

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

Question 66

What allows blood to bypass the liver?

Answer 66

Ductus venosus

Question 67

What does the oval foramen allow?

Answer 67

Blood to enter the left atrium from the right atrium, allowing it to bypass the lungs

Question 68

What allows blood to bypass the lungs?

Answer 68

Oval foramen Ductus arteriosus

Question 69

What does the ductus arteriosus allow?

Answer 69

Blood that still escapes to the right ventricle to bypass the lungs

Question 70

What are the vessels that blood in fetal circulation goes through?

Answer 70

Aorta \> descending aorta \> abdominal aorta \> common iliac artery \> placenta \> umbilical vein

Question 71

What does the ductus venosus become after birth?

Answer 71

Ligamentum venosum of the liver

Question 72

What is the ligamentum venosum of the liver derived from?

Answer 72

Ductus venosus

Question 73

What happens to the oval foramen after birth?

Answer 73

Closes by tissue proliferation and adhesion of septal structures, becoming the fossa ovalis

Question 74

What is the fossa ovalis derived from?

Answer 74

Oval foramen

Question 75

What happens to the ductus arteriosus after birth?

Answer 75

Obliterates to form ligamenum arteriosum

Question 76

What is the ligamentum arteriosus derived from?

Answer 76

Ductus arteriosus

Question 77

Is patent ductus arteriosus (PDA) more common in males or females?

Answer 77

Females

Question 78

What is patent ductus arteriosus (PDA) commonly associated with?

Answer 78

Maternal rubella infection (early pregnancy)

Question 79

What is the cause of patent ductus arteriosus (PDA)?

Answer 79

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

Question 80

Where does coarctation (constriction) of the aorta occur in 90% of cases?

Answer 80

Opposite the ductus arteriosus

Question 81

What causes coarctation of the aorta?

Answer 81

Incorporation of muscle tissue of the ductus arteriosus into arch of aorta (during development), ductus arteriosus constricts after birth so part of the arch also does