B. DERMIS
The second, live and deeper, thicker part of the skin is the Dermis. The dermis is composed primarily of collagen and elastin fibres, with some adipocytes, fibroblasts and macrophages within an interstitial ground substance. Its woven network of fibres has great tensile strength (resists pulling and stretching forces). It also contains blood vessels, lymph vessels, nerves, sebaceous & sweat glands and hair follicles. Leather is the dried and treated dermis of other animals.
There are 2 regions of dermal tissue:
a) Papillary region : thin 1/5 th of total layer thickness and is the superficial layer of the dermis adjacent to the epidermis. It consists of areolar CT containing collagen and fine elastic fibres. Dermal Papillae which are small finger like projections insert into the undersurface of the epidermis. Some of these ridges contain Capillary loops while some contain Meissner Corpuscles (tactile receptors – nerve endings sensitive to touch. b) Reticular region : thicker, deep layer of dermis underlying the papillary region and is attached to the subcutaneous layer. It consists of dense irregular CT containing fibroblasts, bundles of collagen arranged in a netlike manner, and some coarse elastic fibres. There are a few adipose cells, hair follicles, nerves, sebaceous glands, and sudoriferous glands in between the fibres. The
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