Blood Development

Question 1

Stages of blood vessels formation

Answer 1

Vasculogenesis

Angiogenesis

Question 2

What causes blood vessels formation ?

Answer 2

Blood vessels form independently from the heart in response to hypoxia.

Question 3

Define vasculogenesis

Answer 3

Creation of blood vessels

Question 4

Define angiogenesis

Answer 4

Remodelling and pruning of vessels into a recognisable circulatory system

Question 5

Creation of blood vessels

Answer 5

Vasculogenesis

Question 6

Remodelling and pruning of vessels into a recognisable circulatory system

Answer 6

Angiogenesis

Question 7

Explain steps of Vasculogenesis

Answer 7

1. EXTRAEMBRYONIC VASCULOGENESIS
   Condensation of mesenchyme cells in extraembryonic tissues
2. PRIMARY HEART FIELD CREATION
   Creation of blood islands around the embryo.
   Cardiogenic area creates Primary heart field
3. Outer cells become blood vessels, inner cells the primitive/stem blood cells.
4. FORMATION OF UMBILICAL VEINS
   FGF2 stimulates hemangioblast formation. Cords of hemangioblasts join up
   Form early vasculature: in response to VEGF. the umbilical veins

Question 8

How does the Dorsal aorta form?

Answer 8

When primary heart field forms, also get a pair of longitudinal tubes closer to the midline from blood vessels: dorsal aortae.

Posterior sclerotome contributes to endothelial cells and smooth muscle cells for dorsal aorta

Question 9

Endothelial cells and smooth muscle cells migrate to form dorsal aorta in response to what?

Answer 9

To signals from the primary dorsal aorta

Question 10

The aortic sac (top of cardiac tube) develops branches which form?

Answer 10

The 6 AORTIC arches that supply the pharyngeal arches

Branches join on to the dorsal aortae

Question 11

Derivative of branch I?

Answer 11

Disappears: maxillary

Question 12

Derivative of branch II?

Answer 12

Disappears: Hyoid, stapedial

Question 13

Derivative of branch III?

Answer 13

Common carotid

Question 14

Derivative of branch IV ?

Answer 14

L: aorta arch R: R subclavian

Question 15

Derivative of branch V?

Answer 15

Incomplete and regresses

Question 16

Derivative of to branch VI?

Answer 16

Paulmonary arch: Ductus arteriosus +R pulmonary artery

Question 17

Which branch forms the Paulmonary arch: Ductus arteriosus +R pulmonary artery

Answer 17

Branch VI

Question 18

Which branch becomes Incomplete and regresses?

Answer 18

Branch V

Question 19

Which branch becomes on the L: aorta arch, and on the R: R subclavian

Answer 19

Branch IV

Question 20

Which branch develops the common carotid ?

Answer 20

Branch III

Question 21

Which branch Disappears: Hyoid, stapedial?

Answer 21

Branch II

Question 22

Which branch Disappears: maxillary?

Answer 22

Branch I

Question 23

What is Intraembryonic Vasculogenesis?

Answer 23

Intraembryonic blood vessel development

Organ capillaries form within organs from mesoderm

Question 24

What happens during Intraembryonic Vasculogenesis?

Answer 24

Organ capillaries form within organs from mesoderm

Vascular Endothelial Growth Factor (VEGF) stimulates vessel formation and development.

Patterning is variable but not random- vessels grow out in response to signals.

Question 25

Name the process: * Organ capillaries form within organs from mesoderm * Vascular Endothelial Growth Factor (VEGF) stimulates vessel formation and development. * Patterning is variable but not random- vessels grow out in response to signals.

Answer 25

Intraembryonic Vasculogenesis

Question 26

Function of VEGF?

Answer 26

Vascular Endothelial Growth Factor (VEGF) stimulates vessel formation and development.

Question 27

Which factor stimulates vessel formation and development?

Answer 27

VEGF

Question 28

Initial blood cells are formed in ?

Answer 28

EXTRAEMBRYONIC tissues

Question 29

Definitive Hematopoietic stem cells arise from?

Answer 29

Aorta-Gonad-Mesoderm Area (AGM) mesoderm surrounding aorta and will colonise the liver.

Question 30

Liver makes fetal blood cells from?

Answer 30

2-7 months

Question 31

Stem cells colonise bone marrow at ?

Answer 31

7 months

Question 32

What happens during Angiogenesis?

Answer 32

* Existing vessels “sprout” | * Only tip cells though. Induced by VEGF

Question 33

VEGF is induced by ? Why?

Answer 33

Hypoxia Fetal and tissue growth causes cells to need more oxygen, therefore they need that delivery of oxygen - hypoxia - VEGF is stimulated Hypoxia indicated where there is growth and oxygen is needed