Embryology and Histology

Question 1

Which germ layer forms the heart?

Answer 1

Mesoderm

Question 2

Name the 5 parts of the heart tube, from cranial to caudal end (the baby verily acquires stuff…)

Answer 2

Truncus arteriosus
Bulbus cordis
Ventricle
Atrium
Sinus venosus

Question 3

What does the truncus arteriosus of the heart tube produce?

Answer 3

Aorta

Pulmonary trunk

Question 4

What does the bulbus cordis of the heart tube produce?

Answer 4

Right ventricle

Outflow of both ventricles

Question 5

What does the ventricle of the heart tube produce?

Answer 5

Left ventricle

Question 6

What does the atrium of the heart tube produce?

Answer 6

Right and left atria

Question 7

What does the sinus venosus of the heart tube produce?

Answer 7

Right atrium

Coronary sinus

Question 8

Which 3 vessels enter the right + left horns of the sinus venosus?

Answer 8

Vitelline vein
Umbilical vein
Cardinal veins

Question 9

What does the vitelline vein drain?

Answer 9

Yolk sac

Question 10

What does the umbilical vein drain? Which of the veins is definitive?

Answer 10

Placenta

Left

Question 11

What do the cardinal veins act as precursors for?

Answer 11

The systemic venous system

Question 12

Remnants of the left horn of the sinus venosus give rise to the coronary sinus. True/False?

Answer 12

True

Question 13

What is the function of the ductus venosus?

Answer 13

Directs O2-rich blood from placenta (umbilical vein) to IVC, bypassing the liver

Question 14

What is the function of the foramen ovale?

Answer 14

Directs O2-rich blood from RA to LA so it goes to brain and not lungs

Question 15

What is the function of the ductus arteriosus?

Answer 15

Directs deoxygenated blood from pulmonary artery to descending aorta so it goes to placenta to get O2

Question 16

What is the remnant of the umbilical vein in adults?

Answer 16

Ligamentum teres

Question 17

What is the remnant of the ductus arteriosus in adults?

Answer 17

Ligamentum arteriosum

Question 18

What are the three layers of blood vessels from inner to outer?

Answer 18

Tunica intima
Tunica media
Tunica adventitia

Question 19

Arterioles are mainly comprised of…

Answer 19

Tunica media (almost no adventitia)

Question 20

Name the three types of capillaries in order from least to most holey?

Answer 20

Continuous
Fenasterated
Sinusoidal

Question 21

Veins have a thick tunica media. True/ False?

Answer 21

False. It is thin.

Question 22

Valves are inward extensions of…

Answer 22

Tunica intima

Question 23

Give the three layers of the heart from inner to outer

Answer 23

Endocardium
Myocardium
Epicardium
 ---- visceral serous pericardium
 ---- parietal serous pericardium
 ---- fibrous pericardium

Question 24

Layers of heart muscle are connected by… and electrical activity is conducted via …

Answer 24

Desmosomes

Gap junctions

Question 25

In the foetal heart, what connects the umbilical vein (coming from placenta) to the IVC?

Answer 25

Ductus venosus

Question 26

What is the importance of the ductus venosus?

Answer 26

Allows most of the blood from placenta to bypass the liver and go straight to heart

Question 27

In the foetal heart, what connects the right atrium to the left atrium?

Answer 27

Foramen ovale

Question 28

What is the importance of the foramen ovale?

Answer 28

Enables oxygenated blood entering RA (from IVC from umbilical vein from placenta) to enter LA, bypassing pulmonary circulation, i.e. oxygenated blood is not sent to the lungs

Question 29

Once oxygenated blood has moved through the foramen ovale, where does it go?

Answer 29

Enters LV and pumped into the aorta to the body, importantly the brain

Question 30

In the foetal heart, what connects the pulmonary artery to the descending aorta?

Answer 30

Ductus arteriosus

Question 31

What is the importance of the ductus arteriosus?

Answer 31

Enables deoxygenated blood pumped through pulmonary artery to enter descending aorta to go to placenta to get oxygenated

Question 32

Do the lungs take part in gas exchange in the foetus?

Answer 32

No, hence why the pulmonary circulation is cleverly bypassed in the foetal heart

Question 33

What results in closure of the foramen ovale?

Answer 33

Baby's first breath after delivery (usually)

Question 34

What is the remnant of the umbilical vein in adults?

Answer 34

Ligamentum teres

Question 35

What is the remnant of the ductus venosus in adults?

Answer 35

Ligamentum venosus

Question 36

When a duct fails to close, what substance is given to maintain duct patency?

Answer 36

IV PGE2 until surgery

Question 37

What are some signs of congenital heart disease?

Answer 37

``` Cyanosis Murmurs Abnormal pulses Reduced feeding Failure to thrive SOB Sweaty Hepatomegaly Crepitations ```