6. Vascular Dev- Exam 2

Question 1

vascular dev occurs by what 2 mechanisms

Answer 1

vasculogenesis

angiogenesis

Question 2

vasculogenesis=

Answer 2

coalescence of angioblasts

-major vessels such as the dorsal aorta and cardinal veins

Question 3

angiogenesis=

Answer 3

vessels sprout from existing vessels

-remainder of vascular system

Question 4

The early embryonic vascular system is a complex network. Preferential flow is related to what?

Answer 4

the development of organs which leads to enlargement of some vessels while other vessels are obliterated

Question 5

The enlargement of vessels is by way of fusion with smaller vessels and partly by what?

Answer 5

the enlargement of individual capillary bed

Question 6

The major arterial conduits in the early embryo are what? this is a continuation of what that arises from what?

Answer 6

dorsal aortas

-simply in continuation of the endocardial tubes- arise from aortic sac (distal most part of the trunctus arteriosus)

Question 7

because of the changing position of the developing heart tube and pericardium, the cranial portions of the dorsal aortas come to describe what? what does this establish?

Answer 7

describe an arc on both sides of the foregut, establishing the first pair of aortic arches

Question 8

how many pairs of aortic arches are present at some point during development? which one is only transient?

Answer 8

six pairs

5th aortic arch is transient

Question 9

which aortic arch never forms or forms incompletely and regresses

Answer 9

5th aortic arch

Question 10

how are the arches numbered and what do they do as they develop?

Answer 10

1, 2, 3, 4, 6

some become modified and some regress

Question 11

all aortic arches come off of what

Answer 11

aortic sac

Question 12

3 mm embryo:

• first pair of arches is _____
• second pair is just ______
• All other arches develop from the region of the _____
• Distally, the dorsal aortas fuse to form a ______

Answer 12

large
forming
aortic sac
single vessel

Question 13

4 mm embryo (day 27):

• aortic arch is largely ____. Part of it remains and becomes the ______
• Arch 2 is ______. Remnants become the _____
• Arch 3 is _____ and well ______
• Arch 4 and 6 are being formed as ___ and ____ sprouts
• Arch 6 already has a sprouting branch of the ______

Answer 13

disappeared / Maxillary artery
regressing / Stapedial Artery
large / developed
ventral / dorsal
primitive pulmonary artery

Question 14

10 mm embryo (day 29):

• Arch 1 and 2 have _____
• Arches 3, 4, 6 are quite ______
• The _______ has been divided so that arch 6 is now continuous with the _______
• Start to lose _____
• The intersegmental arteries will be important in the formation of the ________

Answer 14

disappeared
large
trunctoaortic sac / pulmonary trunk
symmetry
subclavian arteries

Question 15

14 mm Embryo:

• symmetrical pattern is largely ____
• Further division of the ___ and ____
• Arch 3 forms ____ and ____
• Arch 4 stays on each side but becomes different strucutres: Left=, Right=?
• The dorsal portion of the right arch 6 has _____ and the left arch 6 will become the ______

Answer 15

• gone
• aorta / pulmonary artery
• common carotid artery / first part internal carotid artery
• Left Arch 4= part of aortic arch btwn LCC and left subclavian. Right Arch 4= Proximal righ subclavian
• disappeared / ductus arteriosus

Question 16

14 mm Embryo continued:

• Intersegmental arteries have migrates upward to become the _____
• Arch 6 (Pulmonary Arch) gives off branches that grow toward the developing lung buds. The dorsal portion of the right arch 6 has disappeared and the left arch 6 will become the ______

Answer 16

subclavian arteries

ductus arteriosus

Question 17

17 mm Embryo:

• a portion of the vessel that was the right dorsal aorta _____
• proximal portion persists and becomes the ____

Answer 17

disappears

right subclavian artery

Question 18

At Birth:

• the distal part of the left 6th arch (ductus arteriosus) normally obliterates and becomes the ____
• the adult _____ system is now established

Answer 18

ligamentum arteriosum

aortic arch

Question 19

aortic sac becomes what?

Answer 19

ascending aorta
aortic arch
brachiocephalic artery

Question 20

first arches becomes what?

Answer 20

maxillary artery (portion)

Question 21

second arches becomes what?

Answer 21

stapedial artery (portion)

Question 22

third arches becomes what?

Answer 22

carotid arteries

Question 23

fourth arches becomes what? (right and left)

Answer 23

Right= proximal right subclavian artery
Left= aortic arch segment btwn left carotid and left subclavian artery

Question 24

fifth arches becomes what?

Answer 24

transient and never well-developed

Question 25

sixth arch (RIGHT) becomes what?

Answer 25

Proximal=Proximal right pulmonary artery | Distal=distal portion disappears

Question 26

sixth arch (LEFT) becomes what?

Answer 26

Proximal=Proximal left pulmonary artery | Distal=Ductus Arteriosus

Question 27

right dorsal aorta becomes what?

Answer 27

Portion becomes the right subclavian

Question 28

left dorsal aorta becomes what?

Answer 28

Distal aortic arch and descending aorta

Question 29

right intersegmental artery becomes what?

Answer 29

Part of right subclavian artery

Question 30

left intersegmental artery becomes what?

Answer 30

Left subclavian artery

Question 31

what is the is the major point of entry into the common atria.

Answer 31

sinus venosus

Question 32

the sinus venosus remains paired until the embryo is how long

Answer 32

4 mm | •Even after the endocardial tubes fuse

Question 33

(Sinus Venosus) In a 4 mm embryo, there what is distinguishable

Answer 33

Central (unpaired) portion, Transverse portion Right and left sinus horns

Question 34

Mid 4th week the sinus venosus receives blood from?

Answer 34

the right and left sinus horns.

Question 35

Mid 4th week the sinus venosus receives blood from the right and left sinus horns. Each horn receives blood from what 3 veins?

Answer 35

Vitelline vein Umbilical vein Common Cardinal vein

Question 36

Mid 4th week: Communication between sinus and atrium is wide open. Communication will eventually shift to the? what is this caused by? when does this occur?

Answer 36

shift to the right •Caused by shift in blood in venous system •Occurs at about 4-5 weeks.

Question 37

Obliteration of the right umbilical vein and left vitelline vein occurs when? what looses importance?

Answer 37

Occurs 5th week | Left sinus horn loses importance

Question 38

At week 10 the left common cardinal vein becomes obliterated. What remains?

Answer 38

All that remains of the left sinus horn is the oblique vein of the left atrium and the coronary sinus

Question 39

what enlarges the right sinus horn

Answer 39

Shunt of blood left to right enlarges right sinus horn

Question 40

Right horn and vein are the only communication between what?

Answer 40

the original sinus venosus and the atrium

Question 41

what forms the smooth walled part of the right atrium

Answer 41

Right Sinus horn

Question 42

Sinuatrial orifice (entrance to the common atrium) is flanked on each side by what?

Answer 42

valvular folds

Question 43

Sinuatrial orifice (entrance to the common atrium) is flanked on each side by valvular folds. What happens to the right and left venous valves

Answer 43

* Superior part of the right venous valve disappears * Inferior part of the right venous valve becomes the valve of the inferior vena cava and the valve of the coronary sinus. * Left venous valve fuses with the atrial septum

Question 44

The sinus venosus at this point receives what three pairs of veins: name and describe

Answer 44

1. Vitelline veins=Carry blood from the yolk sac to the sinus venosus 2. Umbilical veins=Originate in the chorionic villi and carry oxygenated blood to the embryo 3. Common cardinal veins=Drain the body of the embryo

Question 45

Vitelline venous system=

Answer 45

* Enters the sinus venosus | * Gives rise to the hepatic veins

Question 46

Umbilical venous system=

Answer 46

* Enter the sinus venosus lateral to the vitelline veins. | * Persists as the umbilical vein in the term fetus

Question 47

Cardinal venous system=

Answer 47

* Enters the sinus venosus lateral/superior to the umbilical veins * Forms a large complex network of veins throughout the body.

Question 48

In the primitive heart (tube), the left and right sinus horns drain into what?

Answer 48

a central sinoatrial orifice

Question 49

10mm Embryo: what happens to the Left vitelline vein

Answer 49

disappeared

Question 50

10mm Embryo: what happens to the Right Vitelline vein

Answer 50

transforming into a structure that will eventually be the hepatic veins and all of the veins of the hepatic portal system

Question 51

10mm Embryo: what happens to the left umbilical vein

Answer 51

has joined the hepatic system. | • The left umbilical vein will persist in the fetus as the umbilical vein

Question 52

10mm Embryo: what happens to the Inferior portion of the cardinal venous system

Answer 52

gaining complexity. | •The left side and right side are migrating inward and joining

Question 53

10mm Embryo: the newly developed subcardinohepatic anastomosis was once the?

Answer 53

right umbilical vein.

Question 54

14mm Embryo: what happens to the left sinus horn

Answer 54

has separated from the right | •Will eventually become the coronary sinus.

Question 55

14mm Embryo: what happens to the right side of the subcardinal venous system

Answer 55

developing into the principle venous channels to the heart from the lower body

Question 56

17mm Embryo: The upper limbs are now drained by?

Answer 56

veins which empty into the anterior cardinal veins

Question 57

17mm Embryo: what happens to the major portions of the posterior cardinal veins

Answer 57

disappeared | •There is even greater demand on the right subcardinal vein

Question 58

24mm Embryo: what happens to the anterior cardinal veins

Answer 58

now have a channel between them (the left brachiocephalic vein).

Question 59

24mm Embryo: what will the cardinal veins do

Answer 59

will drain the entire head and upper extremities.

Question 60

24mm Embryo: what happens to the subcardinal veins

Answer 60

completely fused | •Make up a large portion of what will become the inferior vena cava

Question 61

24mm Embryo: There are now clear venous channels to what organ/gland?

Answer 61

the kidneys and adrenal glands.

Question 62

at term embryo does the the umbilical vein still persist and enter the portal vein?

Answer 62

yes