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Human Body Study

Hypodermis

The deepest layer, beneath the dermis — also called the subcutaneous layer. Strictly it sits just below the skin proper, but it works as part of the integument.

The skin and its appendages A cross-section of skin showing its three layers — epidermis, dermis and hypodermis — together with the hair, sebaceous glands and sweat glands that pass through them. A small inset shows a fingertip with its nail. Each label links to the article for that part. Nails Epidermis Hair Sebaceous glands Dermis Sweat glands Hypodermis Cross-section of skin and its appendages — schematic, not to scale.

Structure

Section titled “Structure”

Mostly loose connective tissue and fat (adipose tissue).

What it does

Section titled “What it does”
  • Insulation — fat slows heat loss.
  • Energy storage — the body’s main subcutaneous fat reserve.
  • Cushioning — pads against impact.
  • Anchoring — ties the skin to the muscle and bone beneath while letting it slide.

Key idea

Section titled “Key idea”

The hypodermis is the body’s main subcutaneous fat store; its thickness varies widely by body region, sex, and individual.