Heart Development

Question 1

____is the formation of blood vessels

Answer 1

Angiogenesis is the formation of blood vessels

Question 2

Blood vessel (and blood cell) formation begins in the ______ and the embryo with __________ that coalesce to form distinct hollow clusters that then merge to form linear hollow tubes or vessels

Answer 2

Blood vessel (and blood cell) formation begins in the yolk sac and the embryo with mesodermal cells that coalesce to form distinct hollow clusters that then merge to form linear hollow tubes or vessels

Question 3

These are apparent in the _______ cranial and ______to the neural plate and extraembryonically in the yolk sac on about day _____

Answer 3

These are apparent in the mesoderm cranial and lateral to the neural plate and extraembryonically in the yolk sac on about day 17

Question 4

The first appearance of the clusters forming tubes that will eventually merge to form the developing heart is in the _________

Answer 4

The first appearance of the clusters forming tubes that will eventually merge to form the developing heart is in the cardiogenic plate

Question 5

The________ contains clusters of angiogenetic cells found anterior and ________ to the neural plate.

Answer 5

The cardiogenic plate contains clusters of angiogenetic cells found anterior and lateral to the neural plate.

Question 6

________ cell clusters in the cardiogenic plate fuse to form a pair of ________ tubes as well as other vessels.

Answer 6

Mesodermal cell clusters in the cardiogenic plate fuse to form a pair of endocardial tubes as well as other vessels.

Question 7

Within another one to two days, the ______ tubes meet and fuse at the midline to form the ________

Answer 7

Within another one to two days, the endocardial tubes meet and fuse at the midline to form the primitive heart tube.

Question 8

The 2 dorsal aorta and endocardial tubes arise as ________

Answer 8

The 2 dorsal aorta and endocardial tubes arise as mesodermal vesicles

Question 9

The endocardial tubes coalesce with lateral folding to form the _______ and ________heart of the of the embryo.

Answer 9

The endocardial tubes coalesce with lateral folding to form the primitive and functional heart of the of the embryo.

Question 10

The lining of the _________ tube will form the _________ layer of the heart.

Answer 10

The lining of the endocardial tube will form the endocardial layer of the heart.

Question 11

Around the ______ week of development, mesodermal cells create blood islands in a horse-shoe shape region of the embryo, that includes the _______ region ______ to the embryo and bilateral to the embryo

Answer 11

Around the third week of development, mesodermal cells create blood islands in a horse-shoe shape region of the embryo, that includes the cardiogenic region cephalic to the embryo and bilateral to the embryo

Question 12

These blood islands coalesce and form a pair of ______ heart tubes.

Answer 12

These blood islands coalesce and form a pair of endocardial heart tubes.

Question 13

During the folding (cephalic and lateral), the ______ heart tubes become fused with one another in the midline, creating one _______ heart tube.

Answer 13

During the folding (cephalic and lateral), the endocardial heart tubes become fused with one another in the midline, creating one endocardial heart tube.

Question 14

The single endocardial tube is invested with _________that differentiates into the ________ layer that is composed of cardiac muscle and the epicardium

Answer 14

The single endocardial tube is invested with splanchnic mesoderm that differentiates into the myocardial layer that is composed of cardiac muscle and the epicardium

Question 15

These two layers are separated from the inner ________ layer by cardiac jelly

Answer 15

These two layers are separated from the inner endocardial layer by cardiac jelly

Question 16

The early heart develops five distinct dilatations. From inferiorly to superiorly, they are:

Answer 16

the sinus venosus, 
the primitive atrium, 
the primitive ventricle, 
the bulbus cordis, and the 
the truncus arteriosus.

Question 17

Note the outflow tract develops into ____ arches within the neck of the embryo

Answer 17

Note the outflow tract develops into 5 arches within the neck of the embryo

Question 18

The innervation of the heart from the_______ is derived from the neck region of the sympathetic chain and the _______

Answer 18

The innervation of the heart from the autonomic nervous system is derived from the neck region of the sympathetic chain and the Xth nerve – the Vagus.

Question 19

Developing primitive heart tube (ventral view) - day 20-21:

Recognize the layers of the developing heart wall - from outer to inner they are:

Answer 19

1) epicardium (a) – from mesothelial cells (splanchnic mesoderm)
2) myocardium (b) – from surrounding splanchnic mesoderm
3) cardiac jelly (c) – acellular extracellular matrix provides form for myocardial growth
4) endocardium (d) – formed by the merging of the endocardial tubes from splanchnic mesoderm

Question 20

The pair of Dorsal aorta in the neck fuse into one dorsal aorta _______
To Vit. & Umb. A.

Answer 20

The pair of Dorsal aorta in the neck fuse into one dorsal aorta posteriorly
To Vit. & Umb. A.

Question 21

6 pairs of arches:

Output of heart is connected by pairs of aortic arches in the neck united to a _________

Answer 21

6 pairs of arches:

Output of heart is connected by pairs of aortic arches in the neck united to a pair of Dorsal Aorta Arteries

Question 22

Primitive Heart Input

Answer 22

Common Cardinal Veins (L&R pair)
- each from the confluence of anterior and posterior cardinal veins
Vitelline veins (L&R pair)
Umbilical Veins (L&R pair)

Question 23

Aorta: ventral aorta connected by arches to the paired dorsal aorta (paired arteries anteriorly in the neck and head but the two dorsal aorta become fused into a single dorsal aorta posterior to the neck)

Answer 23

Vitelline arteries – a pair of arteries that branch off the unified dorsal aorta to the yolk sac plexus
Umbilical arteries – a pair of arteries that branch off the unified dorsal aorta to provide blood to the tertiary villi in the placenta

Question 24

Heart Input (systemic veins in blue):
There are 3 paris of veins:

Answer 24

1.) Common Cardinal Veins (Left and Right): Each is formed by the confluence of anterior and posterior cardinal veins (Left and Right)
- Anterior Cardinal Veins – drain the anterior embryo
- Posterior Cardinal veins – drain the posterior embryo
2.) Vitelline Veins (Left and Right) – return blood from the yolk sac
3.) Umbilical Veins (Left and Right) – return blood from the placenta
Three major pairs of veins and their tributaries bring blood to a confluent venous cavity - the sinus venosus of the heart.

Question 25

Aortic Arches Arterial Vessels

Answer 25

I – terminal branches off the two external carotid arteries forming the paired maxillary arteries

II – mostly regress and only a very small remnant portion is left at birth in the middle ear (the stapedial )

III – forms the common carotid arteries and proximal portion of the internal carotid arteries

IV - On the left side, it persists forming the aortic arch.
- On the right it forms the proximal portion of the right subclavian artery.

V are rudimentary and do not develop into any known vessels.

VI The proximal portions of the right and left side develop into the origin of the right and left pulmonary arteries off the pulmonary trunk, while the distal portion on the left side of develop into the ductus arteriosus

Question 26

III – forms the:

Answer 26

III – forms the common carotid arteries and proximal portion of the internal carotid arteries

Question 27

IV - On the left side, it persists forming the ______ - On the right it forms the proximal portion of the right __________

Answer 27

IV - On the left side, it persists forming the aortic arch.
- On the right it forms the proximal portion of the right subclavian artery

Question 28

VI The ______ portions of the right and left side develop into the origin of the ________ off the pulmonary trunk, while the ________portion on the left side of develop into the ductus arteriosus

Answer 28

VI The proximal portions of the right and left side develop into the origin of the right and left pulmonary arteries off the pulmonary trunk, while the distal portion on the left side of develop into the ductus arteriosus

Question 29

Diverse development of the arches results in normal anatomical variations of arterial branching patterns off _____

Answer 29

Diverse development of the arches results in normal anatomical variations of arterial branching patterns off the aortic arch

Question 30

Malformation of fourth and sometimes sixth arch can result in:

Answer 30

Malformation of fourth and sometimes sixth arch can result in an aortic coarctation

Question 31

The intercostal arteries have an anastomosis that plays a key role in _______

Answer 31

The intercostal arteries have an anastomosis that plays a key role in coarctation

Question 32

Note the ________ of the intercostals supplies the dorsal aorta

Answer 32

Note the anastamosis of the intercostals supplies the dorsal aorta

Question 33

Blood above the _______ enters the subclavian artery on each side

Answer 33

Blood above the coarct enters the subclavian artery on each side