Dermis: Cells week 14

Adipocytes

The terminally differentiated fat cells of the subcutaneous tissue begin to differentiate from the dermal mesenchymal cells beneath the horizontally oriented dermal vascular plexus beginning in the 14th week of gestation.

Dermal fat

This is a low power light micrograph of 16 week EGA showing a several layer thick epidermis and hair follicles exhibiting keratinization (the round structures with the dark centers). The slender elongated irregular dark structures just below the epidermis are blood vessels.

Fat cells show up as clear spaces since most fixation and dehydration procedures using in tissue handling extract the fat from the specimen. The pale zone at about the mid-level of this image is where the adipocytes are found.