Heart I, III & III

Question 1

Where is the Angle of Louie? [level of the spine and level of ribs]

Answer 1

Spinal level T4-T5

At the 2nd rib

Question 2

Coelomic Canal - what does it eventually form? What shape is it? Where does it develop?

Answer 2

Its the primordium of body cavities

Upsidedown “U” shaped

Develops in the lateral plate mesoderm and cardiogenic mesodern

Question 3

What are the two layers of the mesoderm involved in heart development? What do each of them envolve into?

Answer 3

somatopleure mesoderm and splanchnopleure mesoderm

somatopleure - parietal layer of serous pericardium

splanchnopleure - visceral layer of serious pericardium

Question 4

What is congestive cardiac failure (CHF)?

Answer 4

inability to maintain blood circulation

Question 5

What is a cardiac tamponade?

What are the symptoms of a cardiac tamponade?

How do cardiac tamponade occur?

How are they treated?

Answer 5

Blood accumulation in the pericardial cavity.

Beck’s Triad - low arterior BP, JVD, muffled heart sounds

Stab wound or MI

pericardiocentesis

Question 6

What is Ectopia Cordis?

What causes it?

Answer 6

rare- the pericardium and the heart are eposed through a defect in the chest wall

because of a failure of lateral walls to fuse in week 4

Question 7

What is patent foramen ovale?

Answer 7

Most common ASD - failure of fusion between septum primum and septum secundum

long term = pulmonary hypertension

Question 8

What is probe patent foramen ovale?

Answer 8

incomplete fusion between septum primum and septum secundum

Question 9

What is Common atrium (cor triloculare biventriculare)?

Answer 9

the absence of interartial septum

you have only 1 atrium and 2 ventricles

occurs in people who have all 3 defects = ostium secundum fefect, endocardial cushion defect, sinus venosus defect

Question 10

What is primum type ASD ?

Answer 10

Found in down syndrome - foramen primum not closed

Question 11

What is secundum type ASD?

Answer 11

abnormally large foramen secundum or foramen ovale

Question 12

What is sinus venosus type ASD?

Answer 12

defective absorption of sinus venosis into right atrium

Question 13

What is membranous type VSD?

Answer 13

most common of ALL congential heart diseases! = 25%

caused by the failure of tissue from endocardial cushions to fuse with the primordial interventricular septum and the bulbar septum

Failure of contribution from fused endocardial cushions. Defects in muscular part of IV septum are rare. total absence is RARE.

Total absense results in a common ventricle (cor triloculare biatrium) = 1 ventricle and 2 atrium

can have associated mitral valve abnormality

L to R shunting

Question 14

Ascultation of Heart Valves

Answer 14

Question 15

What is the tetralogy of Fallot?

Answer 15

Pulmonary stenosis - primary defect due to asymmetrical partitioning of truncus artieriosis

right ventricular hypertrophy

Ventricular septal defect (VSD)

overriding Aorta

Question 16

What are the treatment options for CHD?

Answer 16

PTCA-Coronary angioplasty

Coronary bypass graft

Question 17

What PTCA in coronary angioplasty?

Answer 17

Percutaneous (through skin)

Transluminal (within lumen)

Coronary (a. which suppliies the heart)

Angioplasty (remodeling the a.)

Question 18

Where does blood form?

Answer 18

from blood islands in the Yolk sac

Question 19

What induces etraembryonic splanchnic mesoderm?

Answer 19

extraembryonic endoderm

Question 20

What are angioblasts?

Answer 20

vessel-forming cells - endotheliual cell precursors differentiated mesenchymal cells

aggregate to form blood islands

Question 21

What are hemangioblasts?

Answer 21

specialized endothelial cells

blood-forming cells

Question 22

What is cardiogenic mesoderm?

Answer 22

upsidedown “U” shape extending back on both sides of the foregut

Question 23

What induces early heart tissue?

Answer 23

endoderm

Question 24

What does the splancnic mesoderm have?

Answer 24

cardiogenic plate - whcih is anterior to the oropharyngeal membrane

Question 25

Where is the developing pericardial cavitiy located?

Answer 25

between somatic and splanchnic mesoderm

Question 26

What do the vesicles in the pre-cardiac splanchnic mesoderm fuse to form?

Answer 26

paired endocardial primordia on both sides of the foregut

Question 27

Explain lateral folding (heart formation)

Answer 27

endocardial primordia fuse along the midline = primitive tubular heart

inner endocardial lining becomes the endocardium - surrounded by a matrix called cardiac jelly

myocardium surrounds the cardiac jelly

Question 28

What are the two folding events that take place in the formation of the heart?

Answer 28

lateral folding and head folding

Question 29

What happens duing head folding?

Answer 29

the heart tube and pericardial cavity rotatate 180 degrees

lie ventral to foregut and caudal to oropharyngeal membrane

Question 30

What direction do the heart tubes fuse and what to they form eventually?

Answer 30

begins cranially and ends caudally

forms a single heart tube

Question 31

What happens during heart elongation?

Answer 31

bending of the heart tube to the right

bulbus cordis go down and the ventricles and atrium turn up

Question 32

What is the direction of the primordial blood flow?

Answer 32

sinus venosus - atrium - ventricle - bulbus cordis - truncus arteriosis - aortic sac - pharyngeal arch arteries

Question 33

What are the endocardial cushions and what is there significance?

Answer 33

they form on the dorsal and ventral walls of the AV canal

the dorsal and ventral cushions fuse = divide AV canal into R and L AV canal

role in the formation of interartial and interventricular septum

Question 34

What happens during partitioning the primordial atrium?

Answer 34

septum primum and septum secundum are formed

foramen primum and foramen secundum are formed

2 foramen + 2 septum

Question 35

What gives rise to the foramen ovale?

Answer 35

the septum secundum

the septum primum forms the valve of the oval foramen = after birth, fuses with septum secundum and forms fossa ovale

Question 36

What do the parts of the sinus venosus form? [right horn, left horn, opening, sinus verarum, crista terminalis]

Answer 36

right horn = SVC and IVC

left horn = coronary sinus

the opening shifts to the right = right atrium

sinus venarum = smooth wall of right atrium

crista terminalis = separates the sinus verarum from primordial atrium

Question 37

Where are bulbar and truncal ridges derived from?

Answer 37

neural crest mesenchyme

Question 38

How are aorta and pumonary trunk formed?

Answer 38

the formation of the aorticopulmonary septum divides bulbis cordis and truncus artiosus into aorta and pulmonary trunk

Question 39

What are the right to left shunts in fetal circulation?

Answer 39

foramen ovale and ductus arteriosus

Question 40

What changes occur from fetal circulation to neonatal circulation?

Answer 40

foramen ovale closes = fossa ovale

ductus arteriosus closes = ligamentum arteriosum

Remember - ductus venosus bypasses the liver!

Question 41

What is Patent Ductus Arteriosus (PDA)?

Answer 41

L to R shunt

pulmonary hypertension

assocated with materal rubella infection in early pregnancy

Question 42

What is coarctation of the Aorta?

Answer 42

constriction of the aorta

upper limb hypertension

associated with Turner’s syndrome

Question 43

What is transposition of great arteries?

Answer 43

most common cause of cyanotic heart disease in new borns

switching of aorta and pumonary trunk

immediately lethal unless combines with another defect - PDA, ASD, VSD