E1 Development Of The Heart

Question 1

List the 4 basic stages of heart development

Answer 1

1. Cardiac Crescent
2. Heart Tube
3. Pre-septated looped heart
4. Four chambered heart

Question 2

Heart development begins during week ____

Answer 2

3

Question 3

Progenitor heart cells migrate through the primitive streak into the _____

Answer 3

Splanchnic layer of lateral plate mesoderm

Question 4

1st sign of heart formation -> a solid horseshoe-shaped cluster of cells known as _____

Answer 4

Primary Heart Field (PHF)

Question 5

Once cells establish the PHF, they are induced by underlying _____ to form cardiac myoblasts and _____ and ____ by the process of ______

Answer 5

Endoderm

Blood islands
Vessels

Vasculogenesis

Question 6

Process of blood vessels arising from blood islands

Answer 6

Vasculogenesis

Question 7

Process of blood vessels sprouting from existing vessels

Answer 7

Angiogenesis

Question 8

Blood islands will unite and form horseshoe-shaped endothelial lined tube known as _____ tubes surrounded by myoblasts within the ____ region.

Other blood islands appear which will form the pair of longitudinal _____

Answer 8

Endocardial

Cardiogenic

Dorsal aortae

Question 9

Lateral body folding creates the _____ (developing heart)

Answer 9

Primordial Heart Tube

Question 10

______ folding is what repositions the developing heart and pericardial cavities

Answer 10

Cranial-caudal (Sagittal)

Question 11

Initially, heart tube is attached to dorsal side of pericardial cavity via _____, but the middle section of this structure will disappear and create the ____. At this time the heart tube consists of three layers:

Answer 11

Dorsal Mesocardium

Transverse Pericardial Sinus

1. Endocardium
2. Myocardium
3. Epicardium (Visceral Pericardium)

Question 12

List the steps of heart development

Answer 12

1. Establishing/patterning of primary heart field (PHF)
2. Heart tube formation/positioning
3. Cardiac Loop formation
4. Sinus venosus development
5. Partitioning of heart

Question 13

R/L horns of Sinus Venosus develop into

Answer 13

L horn: Coronary sinus

R horn: Sinus Venarum (smooth-walled portion of R atrium)

Question 14

Primordial atrium develops into

Answer 14

R/L auricles and portions of atria

Question 15

Primordial Ventricle develops into

Answer 15

L Ventricle

Question 16

Conus Cordis (part of Bulbus Cordis) develops into

Answer 16

Outflow tract of ventricles; caudal portion of bulbous cordis forms R Ventricle

Question 17

Truncus Arteriosus forms

Answer 17

Pulmonary Trunk and Aorta

Question 18

Tubular heart undergoes _____ looping to form U-shaped loop that results in heart with apex pointing to the ____.

Answer 18

Right-handed

Left

Question 19

Sinus venosus receives venous blood from 3 paired veins:

Answer 19

1. Vitelline vv
2. Umbilical vv
3. Common Cardinal vv

Question 20

With the obliteration of the L umbilical and L vitelline (due to blood flow shift to the right side), left sinus horn becomes:

Answer 20

Oblique veins of the left atrium

Coronary Sinus

Question 21

Right sinus horn becomes incorporated into the ____ to form the ____ (smooth-walled part). Its entrance is the _____

Answer 21

R Atrium

Sinus Venarum

Sinuatrial Orifice

Question 22

Septa formation happens in two ways:

Answer 22

1. Endocardial Cushions

2. Merging two expanding portions of the wall

Question 23

Near the end of week four, _____ form on each side plus one at the dorsal and ventral walls of AV canal

Answer 23

4 AV endocardial cushions

Question 24

Fusion of the endocardial cushions results in complete division of the _____ into a ___ and ____ portion

Answer 24

AV canal

Left
Right

Question 25

Around end of week 4, a crest of tissue known as ____ grows from the roof of the common atrium. It will extend toward the endocardial cushions in the AV canal with an opening below them known as ____

Answer 25

Septum Primum

Ostium Primum

Question 26

As holes in the septum primum coalesce to form the ____, a thicker ____ develops from the roof of the primordial atrium slightly to the right of septum primum

Answer 26

Ostium Secundum

Septum Secundum

Question 27

Septum Secundum grows inferiorly and develops an opening known as _____

Answer 27

Foramen Ovale

Question 28

After birth, the pressure in the left atrium increases as the blood returns from the lungs, septum primum is pressed against the septum secundum and adheres to it, permanently closing the ____ and forming the _____

Answer 28

Foramen ovale

Fossa ovalis

Question 29

End of week 4, primitive ventricles begin to expand, medial walls will merge to form _____ with _____ located about it.

Answer 29

Muscular Interventricular Septum

Interventricular Foramen

Question 30

Outgrowth of the inferior endocardial cushion closes the Interventricular foramen. Complete closure forms the _____ part of the Interventricular septum

Answer 30

Membranous

Question 31

During week 5, ____ migrate into truncus arteriorsus and bulbous cordis to form _____, which will undergo a 180 degree spiraling which results in formation of a spiral ____ when they fuse.

Answer 31

Neural crest cells

Truncal and Bulbar ridges

Aorticopulmonary septum

Question 32

Most common congenital heart defect (25%). Failure of IV septum to completely form. Can involve membranous or muscular portion of septum.

Answer 32

Ventricular Septal Defect (VSD)

Question 33

Primordial pulmonary v and branches develop into

Answer 33

Smooth-walled portion of left atrium

Question 34

Aortic sac develops into

Answer 34

Ascending aorta

Question 35

Congenital heart defect present at birth. Usually four different types of defects (VSD, Pulmonary Stenosis, R Ventricular Hypertrophy, Overriding Aorta).

Answer 35

Tetralogy of Fallot