16. Great Vessels Flashcards
What is the difference between splanchnic mesoderm and mesenchyme?
Mesenchyme is embryonic connective tissue which is mainly mesoderm and has some neural crest
Lung is made up of splanchnic mesoderm while heart is made of mesenchyme: splanchnic mesoderm and neural crest which help make bulbar ridges and the aorticopulmonary septum
Undifferentiated mesoderm differentiates into angioblasts/hemangioblasts which give rise to which two cells?
Hematopoetic Stem Cells and endothelial precursor cells (EPC)
Hemangioblasts aggregate and form blood islands which have the EPCs forming the vessels and channels, and inside the EPCs youll find the?
Hematopoietic Stem cells, BLOOD ISLANDS
Where do the blood islands form? (HPCs)
The extraembryonic mesoderm that surrounds the umbilical vessel/ yoke sack and in the region of the aortic gonad mesenephrose (AGM)
Once the blood islands form, they accumulate and form plexuses. Channels within the plexus enlarge to form?
The arteries and the veins
What is the definition of vasculargensis (starts end of 3rd week)?
Formation of new vascular channels by assembly of individual cell precursors called angioblasts (mesoderm)
What is the difference between agiogenesis and arteriogenesis?
Angio: development of blood vessels from preexisting vessels
Arterio: Remodeling of existing arteries in response to changes
Angiomas can form is something went wrong. Capillary hemangioma is excessive growth of small capillary networks. What occurs during cavernous hemangioma/ hemangioma of infancy?
Proliferation of large dilated vascular channels, benign tumor that get bigger betweenbirth and first year of life and then regress, 10% white bbs **endothelial cells by vasculogenesis (EPCs)
Paired dorsal aorta, there are two d/t there being two heart tubes that come together. What is the flow of blood during the fourth week?
Bulbus cordis to trucus arteriosus to aortic sac to pharyngeal arch arteries (1-2-3-4-6) all have own arches, then finishes in dorsal aorta
The paired dorsal aorta fuse in the region of the abdomen, and in the region of the thorax they?
remained paired so they can be remodeled to form blood vessels
What are the three branches off of the fused abdominal aorta?
- Ventral segemental arteries
- Lateral segmental arteries
- Dorsal segmental arteries
Ventral segmental arties supply structures that came from the splanchnic layer of the lateral plate mesoderm and endoderm, such as?
Celiac Trunk, Superior mesenteric artery and inferior mesenteric artery (IMA)
Lateral segmental segmental supply structures that came from the intermediate mesoderm, such as?
Gonads and Kidneys- Renal arteries and gonadal arteies
Dorsal segmental arteries supply derivatives of the somites, such as?
Intersegmental arteries, such as intercostal arteries and lumbar arteries
As aortic arches form during days 26-32, 1 forms first, then second and third, and as third forms, one degrades, and as fourth formss?
second degrades, as 6 forms, third degrades, done by days 32-37 sending branches to the developing head
The 1st aortic arch/ pharyngeal arch gives rise to?
External carotid and maxillary arteries
The 2nd aortic arch gives rise to?
stems of the stapedial arteries in the ear
The Aortic sac gives rise to?
brachiocephalic artery and base of arch of aorta
The 3rd pharygeal arch/aortic arches gives rise to?
common carotid and internal carotid arteries
The 4th pharyngeal arch/aortic arch gives rise to?
Left: medial portion of arch of aorta
right: proximal right subclavian