Question

1. For adipose development, the number of adipocytes become largely constant after adolescence. The major reason is?

Progenitor density reduces as animals become older.

Adipocyte hyperplasia stops at birth.

Adipocyte hypertrophy occurs mainly during the fetal stage.

Progenitor cells are depleted after birth.
2. Which of the following vessels does NOT have valves?

Artery      
Vein       
Lymph vessels
None of above

3. The blood vessels (Vein and artery) have three layers; the inner layer is composed of endothelial cells, which are originated from?

Ectoderm
Mesoderm
Endoderm      
Extraembryonic membrane

Answer 1

1. Progenitor cells are depleted after birth.

The reason behind is the number of fat cells remain constant the majority of time and only ten percent death occur which is recovered annually. Obesity results in increasing the size of fat cells. In 1970 a term Fatter fat cell terms were used.

2. Arteries lack valves.

The main purpose of valves is to prevent the backflow of blood or lymph opposing their passage routes. Arteries have the pressurized blood pumped by the heart. This pressure is enough to drive blood in its way and prevent its backflow

3. The Inner layer of vein arises from mesoderm.

The veins are composed of three layers- Tunica externa (extrenal layer), Tunica media(middle layer), and tunica intima(inner layer). during the development the mesoderm is differentiated into the layers that form veins and arteries.