Embryology - Cvs

Front 1

Vasculogenesis
a. what
b. difference from angiogenesis
c. from which tissue
d. growth factors

Back 1

a. development of the blood system (via blood islands)

b. angiogenesis is development of new blood vessels (branching), while vasculogenesis is development "de novo"

c. mesoderm of mesenchyme

d. FGF2 & VEGF (needed for mesenchymal cells -> hemangioblasts (hematopoietic stem cells) and angioblasts (-> endothelium)

Front 2

Heart begins to beat on

Back 2

22nd day
(Circulation does not start until days 27-29)

Front 3

Tubular heart is formed first via 3 "structures"

Back 3

1. angioblastic cords ->
2. endocardial heart tubes ->
3. tubular heart

Front 4

Angioblastic cords
a. what
b. where

Back 4

a. cordlike masses of splanchic mesenchymal cells, arrange themselves side-by-side to form the primordia of the endocardial haert tubes

b. lie ventrally to the primordial pericardial celom

Front 5

Endocardial heart tubes

Back 5

Endothelial heart tubes in which two tubes come together an fuse in the midthoracic region to form the primordial cardiac\heart tube

Front 6

Celom

Back 6

A cavity in the mesoderm of an embryo that gives rise in humans to the pleural, peritoneal or pericardial cavity

Front 7

Ventral folding of the head region cause the heart and pericardial to lie ... to the foregut, and ... to the oropharyngeal membrane

Back 7

ventral to the foregut, caudal to the oropharyngeal membrane

Front 8

Lateral folding of the embryo cause what in regards to the primordial heart

Back 8

1. Pericardial celom expand and fuse at the midline ventrally (dorsally the primordial heart is still connected by the dorsal mesocardium)

2. Fusion of the endocardial heart tubes

(inbudding of gut from yolk sac)

Front 9

Back 9

1. Cut edge of amnion
2. Pericardial coelom (ventral to brain)
3. Neural groove
4. Neural fold
5. 3rd somite
6. Primordial\primitive node (local thickening of the blastoderm at the cephalic end of the primitive streak of the embryo)
7. Primitive\primordial streak (ridge of epiblast in the midline at the caudal end of the embryonic disk from which arises the intraembryonic mesoderm and definite endoderm, day 15)
8. Mesenchyme (embryonic CT)
9. Neural groove
10. Neural fold
11. Dorsal aorta
12. Notochord (the axial fibrocellular cord about which the vertebral primordia develop, persist as nuclei pulposi in adult)
13. Lateral fold
14. Wall of yolk sac
15. Endocardial heart tube
16. Pericardial coelom (future pericardial cavity)
17. Amnion
18. Neural groove
19. Dorsal aorta
20. Foregut
21. Pericardial cavity
22. Amnion
23. Fusing endocardial tubes
24. Cardiac jelly
25. Myocardium
26. Pericardial cavity
27. Dorsal mesocardium
28. Epicardium (visceral pericardium)
29. Parietal pericardium

Front 10

Cardiac jelly

Back 10

The gelatinous, noncellular material between the endothelial lining and the myocardial layer of the heart in very young embryos

Later in development it serves as a substrate for cardiac mesenchyme

Front 11

Dorsal mesocardium
a. what
b. becomes

Back 11

a. The part of the mesocardium dorsal to the embryonic heart

b. It breaks down to form the transverse sinus of the pericardium

Front 12

Mesocardium

Back 12

The double layer of splanchnic\visceral mesoderm supporting the embryonic haert in the pericardial cavity, it disappears before birth

Front 13

Heart tube - components

Back 13

1. Sinus venosus (paired)
2. Primitive atrium (paired)
3. Primitive ventricle
4. Bulbus cordis (a transitory dilation where the arterial trunk joins the ventral roots of the aortic arches)
5. Truncus arteriosus (the common arterial trunk, opening out of both ventricles in early fetal life)

Front 14

The primitive heart tube

Back 14

The earliest stage of heart development, forms primarily from splanchnic mesoderm from endocardial tubes

(Components: sinus venosus, primitive atrium, primitive ventricle, bulbus cordis, truncus arteriosus)

Front 15

The primitive ventricle, give rise to

Back 15

Give rise to the trabeculated parts of the left and right ventricles

Front 16

Bulbus cordis - give rise to

Back 16

The smooth part of the the left and right ventricles

(lies ventral to the primitive ventricle after the developing heart assumes its S-shaped form)

Front 17

Sinus venosus
a. what
b. give rise to

Back 17

a. A cavity at the caudal end of the embryonic cardiac tube in which the veins from the intra- and extraembryonic circulatory arcs unite

b. form the adult derivative sinus of the vena cava (the portion of the right atrium that receives blood from the venae cavae and is separated from the rest of the atrium by the crista terminalis)

Front 18

Sinus of the vena cava

Back 18

The portion of the cavity of the right atrium that receives the blood from the venae cavae, separated from the rest of the atrium by the crista terminalis

Front 19

Truncus arteriosus
a. what
b. gives rise to

Back 19

a. The common arterial trunk opening out of both ventricles in early fetal life

b. aorta and pulmonary trunk by development of the spiral septum

Front 20

Transverse septum
a. what
b. covered with what
c. becomes

Back 20

a. The mesodermal mass separating the pericardial and peritoneal cavities

b. It is covered with mesothelium except where it is intimately associated with the liver (which develops within in it, this part becomes the bare area of the liver)

c. The central tendon of the diaphragm

Front 21

Back 21

Front 22

Blood islands
a. what
b. when & where

Back 22

a. An aggregation of splanchnic mesoderma cells on the embryonic yolk sac, has the potential to form vascular endothelium and primitive blood cells

b. day 17: forms in extra-embryonic mesoderm, day 18 in intra-embryonic mesoderm, day 19 forms cardiogenic mesoderm (pair that later coalesce)

Front 23

Extraembryonic mesoderm\primary mesoderm

Back 23

a. Cells derived from the epiblast fill the space between the trophoblast and the two cavities (amnion, yolk sac) and forms their own celom - the extraembryonic celom\chorionic cavity)

Front 24

Intraembryonic mesoderm\Secondary mesoderm

Back 24

Mesoderm derived from the primitive streak and lying between ectoderm and endoderm

Front 25

The endocardial heart tube induces the cardiogenic mesoderm to differentiate into four layers

Back 25

Inner->Outer
1. Cardiac jelly
2. Myocardium
3. Epicardium
4. Pericardial cavity

Front 26

The heart tube folds

Back 26

Ventrally, caudally and to the right --> S-shaped tube

Front 27

The heart tube fold at 2 sites

Back 27

1. The bulboventricular sulcus (-> ventricular septum)
2. The atrioventricular groove

Front 28

The 3 partitionings of the heart

Back 28

1. Partitoning of the AV canal
2. Partitoning of the primordial atrium
3. Partitoning of the primordial ventricle

(From mid 4th week-->end of 5th week)

Front 29

Partitioning of AV canal

Back 29

By fusion of ventral and dorsal endocardial\AV canal cushions

(AV canal cushions: a pair of mounds of embryonic CT covered by endothelium. Bulges into the embryonic AV canal, located one dorsally and one ventrally. Grow together and fuse with each other and with the lover edge of the septum primump, thus dividing the originally single canal into right and left atrioventricular orifices

Front 30

AV canal\Endocardial cushions
a. what
b. which
c. do what

Back 30

a. A pair of mounds of embryonic CT covered by endothelium

b. Located one dorsally and one ventrally

c. They bulge into the embryonic AV canal, they grow together and fuse with each other and with the lower edge of the septum primum, dividing the originally single canal into right and left AV orifices

Front 31

Development of partitoning of atrium

Back 31

1. Septum primum grows inferiorly, the increasingly smaller inferior gap is know as ostium primum
2. The septum primum fuse with the endocardial cushion closing the ostium primum, meanwhile perforations in the superior part appear and develop into ostium secundum (->->fossal ovalis)
3. Septum secundum develops to the right of septum primum. It grows by upper limb (anteroinferior) and lower limb (anterosuperior)
4. Foramen ovale appears as canal through upper & lower limb of septum secundum and foramen secundum
4. Superior limb of septum secundum grow further anteroinferior and create a valve between it and the inferior part of foramen secundum
5. Decreased pressure in pulmonary circulation switch the blood flow and functionally occluding the foramen ovale after 1st breath

Front 32

Back 32

Front 33

Ductus arteriosus\Botallo duct
a. Closes how
b. When

Back 33

a. The duct is kept open during fetal life by a continuous production of PGE2 by the ductus. higher pO2 -> lower PGE2 -> smooth muscle constriction. Following the constriction fibrosis occurs. (patent DA can be treated with indomethacin or ibuprofen (NSAIDs)

b. It is substantially closed after 12-24h and completely sealed after 3 weeks

Front 34

Ductus venosus
a. Closes how
b. When

Back 34

a. Uncertain, appear to be a decrease in pressure in the portal sinus (resulting in retraction and narrowing of its origin which thus assumes a slit-like appearance), also probably reinforced by muscular elements in the wall of the portal sinus near the origin of the duct

b. functional: 1st minute parturition, organic closure: within 15-20th day

Front 35

Partitioning of the primordial ventricle

Back 35

1. Primordial interventricular septum (becomes muscular part of the IV septum)(from ventricular wall)
2. Membranous part of IVS (from fused bulbar ridges and fused endocardial cushions)(last to fuse)

Front 36

The bulbar\conotruncal ridge
a. what
b. gives rise to
c. derived from

Back 36

a. one of two spiral subendocardial thickenings in the embryonic bulbus cordis

b. when they fuse, they divide the bulbus into the aorta and pulmonary artery, contribute to formation of semilunar valves, and contribute to formation of membranous IVS

c. derived from ectomesenchyme from cranial neural crest

Front 37

The endocardial\AV canal cushions
a. what
b. give rise to

Back 37

a. a pair of mounds of embryonic CT covered by endothelium

b. part of membranous part of IVS, divide the AV canal, contribute to formation of the AV valves, contribute to septum primum in atrium

Front 38

Partitoning of bulbus cordis and truncus arteriosus
a. By what
b. How

Back 38

a. By bulbar and truncal ridges which form aortico-pulmonary septum\spiral septum
b. perform a 180 degree spiraling and fusing

Front 39

The aorticopulmonary\Spiral septum
a. formed by, induced by

b. Function

Back 39

a. Arise within the truncus arteriosus from downward helical growth and fusion of conotruncal ridges (one on each side), which is induced by invasion of neural crest cells

b. Divide the ventricular outflow between the pulmonary artery and the ascending aorta

Front 40

Eisenmenger's syndrome

Back 40

Occurs as a result of equal division of the truncus arteriosus with an incomplete fusion of bulbar ridges proximally involving the membranous part of the IVS. This results in

1. Persistent truncus arteriosus
2. IVSD
3. Left-to-right shunt -> pulmonary hypertension (capillaries are destroyed and replaced by scar tissue (decrease diffusion surface & cause sclerosis -> increased afterload) -> shunt reversal

Front 41

Which syndrome occurs when the division of the AP septum occurs asymmetrically

Back 41

Tetralogy of Fallot

Front 42

Dorsal folding of heart
a. effect on direction of heart tube
b. mediated by
c. fold at
d. forms what
e. does what to the fibrous skeleton of the heart

Back 42

a. Inflow and outflow trunks are positioned posteriorly

b. Mediated by apoptosis in the dorsal mesocardium

c. The bulboventricular sulcus

d. Forms the two pericardial sinuses

e. Places the fibrous skeleton in a single plane

Front 43

Superior vena cava develops from

Back 43

Right anterior cardinal vein and the right common cardinal vein

Front 44

Critical period for development of the heart and the great vessels

Back 44

3rd-6th week

Front 45

Frequency of anomalies of heart and great vessels

Back 45

6-8\1000 births

Front 46

Aortic arch derivatives - 1st pair

Back 46

1. Maxillary aa
2. External carotid aa

Front 47

Aortic arch derivatives - 2nd pair

Back 47

Stapedial & hyoid aa

Front 48

Aortic arch derivatives - 3rd pair

Back 48

Proximal -> Common carotid aa
Distal -> Internal carotid aa

Front 49

Aortic arch derivatives - 4th pair

Back 49

Left -> part of arch of aorta
Right -> right subclavian artery (distal part forms from the right dorsal aorta

Left subclavian artery is not derived from an aortic arch, its derived from the 7th intersegmental artery

Front 50

Origin of subclavian arteries

Back 50

Right <- right 4th pair of aortic arch, distal part from right dorsal aorta

Left <- 7th intersegmental artery

Front 51

Aortic arches
a. what
b. how many

Back 51

a. A series of arterial channels encircling the embryonic pharynx in the mesenchyme of the branchial arches

b. potentially 6 pairs, but in mammals the 5th is poorly developed or absent

Front 52

Aortic arch derivatives - 6th pair

Back 52

Left
a. proximal -> left pulmonary artery
b. distal -> Ductus arteriosus (Botali)
Right -> right pulmonary artery

Front 53

Back 53

Front 54

The vitelline veins give rise to the aduldt derivatives

Back 54

1. Hepatic veins (from the remains of the right vitelline vein

2. Portal vein (from an anastomotic network around the duodenum)

Front 55

Umbilical veins - fetal development

Back 55

Right and part of the left vein degenerate, the persistent part of the left become the umbilical vein

(the ductus venosus shunt ca 50% the blood it returns through the liver)

Front 56

Changes in the sinus venosus - fate of right horn

Back 56

It enlarges, receives all the blood from the head and neck (SVC) and caudal regions (IVC)

It becomes incorporated into the wall of the right atrium

Front 57

Changes in the sinus venosus - fate of left horn

Back 57

Decrease in size and importance - to become coronary sinus

Front 58

Types of atrial septal defects

Back 58

1. Patent foramen ovale (in 25% of people a probe patent foramen ovale exists)

2. Ostium secundum defects

3. Endocardial cushion defect involving ostium primum (often associated with AV valve defects)

4. Common atrium

Front 59

Patent ductus arteriosus
a. Most common in
b. Who is at risk

Back 59

a. Most common in preterm infants (60% close spontaneously wi 3 days)

b. Preterm, Down's, Maternal Rubella infection during pregnancy, 2x as common in girls

Front 60

Tetralogy of Fallot - 4 components

Back 60

1. Pulmonary stenosis (valvular or infundibular\conus arteriosus(from supraventricular crest to pulmonary trunk, smooth-walled)
2. Right ventricular hypertrophy
3. Dextroposition of aorta (Overriding aorta)
4. Ventricular septal defect

Front 61

Dextrocardia

Back 61

Initial malrotation of the heart tube bending left instead of right.

(Results in heart and greater vessels reversed, can also occur with situs inversus)
(Not symptomatic. Defibrillate on the right side)

Front 62

Coarctation of the aorta
a. types

Back 62

a. preductal (5% of turner syndrome), ductal, postductal (most common)

(Associated with bicuspid aortic valve, defect in which only one ventricle is present, VSD)

Front 63

Long QT syndrome
a. what, effect
b. cause

Back 63

a. Group of rare genetic disorders with prolonged ventricular repolarization and a risk of ventricular tachyarrhythmias.

b. Cause is mutation in genes encoding either cardiac ion channels or channel interacting proteins.

Front 64

Groups of congenital heart diseases

Back 64

Group 1: left->right shunts (acyanotic heart disease, frequent infections, include VSD, ASD, PDA, AV canal)
Group 2: right->left shunts (tetraology of Fallot, overriding aorta, pulmonary stenosis, right ventricular hypertrophy)
Group 3: Obstructive lesions