Heart Development - Blood Vessels

Question 1

What are the most common life-threatening congenital defects?

Answer 1

Heart defects

Question 2

Vasculogenesis

Answer 2

Process of making blood vessels directly from mesenchyme

Question 3

When and where does extraembryonic vasculogenesis and early hematopoeisis begin?

Answer 3

Begins at day 17 in the mesoderm of the yolk sac wall

Question 4

In the mesoderm of the yolk sac wall, hemangioblasts give rise to what 2 cell populations?

Answer 4

1. Hematopoietic Progenitor Cells

2. Endothelial Precursor Cells (EPCs)

Question 5

Where do blood islands form?

Answer 5

Yolk sac wall mesoderm

Question 6

What cells organize to form the blood islands?

Answer 6

1. Hematopoietic Progenitor Cells

2. Endothelial Precursor Cells (EPCs)

Question 7

What cells make up the Primitive Hematopoietic Stem Cells (HSCs)?

Answer 7

1. Hematopoietic Progenitor Cells

2. Endothelial Precursor Cells (EPCs)

Question 8

At what day to the primitive HSCs populate the primordial liver?

Answer 8

Day 23

Question 9

What do the primitive HSCs create?

Answer 9

Embryonic erythrocytes and macrophages

Question 10

What creates the definitive HSCs?

Answer 10

Hemogenic endothelial cells

Question 11

Where are hemogenic endothelial cells located and what do they give rise to?

Answer 11

Located: aortic-gonadal-mesonephric region of dorsal aorta (AGM)
Give rise to: Definitive HSCs

Question 12

Between what days are the hemogenic endothelial cells of the AGM region of the dorsal aorta activated?

Answer 12

Day 27-40

Question 13

Once the Definitive HSCs are in the liver, they can then generate?

Answer 13

Full spectrum of myeloid and lymphoid cell lineages

Question 14

Where will the Definitive HSCs eventually populate?

Answer 14

Lymph organs and bone marrow

Question 15

Source of early RBCs and macrophages from primitive HSCs

Answer 15

Yolk sac wall mesoderm

Question 16

Colonized by primitive HSCs by day 23

Answer 16

Liver primordia

Question 17

Hemogenic endothelial cells activated here between days 27-40

Answer 17

AGM dorsal aorta

Question 18

Site of production of definitive HSCs from 5th week to birth

Answer 18

Liver

Question 19

Eventual major hematopoietic organ

Answer 19

Bone marrow

Question 20

Blood vessel formation NOT coupled with hematopoiesis

Answer 20

Intraembryonic vasculogenesis

Question 21

At what day does intraembryonic vasculogenesis begin?

Answer 21

Day 18

Question 22

For intraembryonic vasculogenesis, splanchnic mesoderm creates what cells?

Answer 22

Endothelial Precursor Cells (EPCs)

Question 23

Angiogenesis

Answer 23

Sprouting of new vessels from existing ones

Question 24

Intussusception

Answer 24

Splitting of 1 vessel into 2

Question 25

For intraembryonic vasculogenesis, EPCs go on to form endothelial cells that form?

Answer 25

Vasculogenic cords and tubes - blood vessels

Question 26

What are 2 ways that intraembryonic vasculogenesis continues to grow its network?

Answer 26

Angiogenesis

Intussusception

Question 27

Angioma

Answer 27

Abnormal blood vessel and lymphatic capillary growth via vasculogenesis

Question 28

Excessive formation of capillaries?

Answer 28

Capillary hemangioma

Question 29

Excessive formation of venous sinuses?

Answer 29

Cavernous hemangioma

Question 30

Hemangiomas of infancy are usually _____ tumors that _____

Answer 30

Benign tumors that regress

Question 31

Abnormal blood vessel and capillary growth

Answer 31

Angioma

Question 32

What process can cause an angioma?

Answer 32

Vasculogenesis