BIO 304 . Human Anatomy & Physiology . American River College
Skin Structure and Layers
Module 4 . Integumentary System
Epidermis, dermis, hypodermis: who lives where and what they do. Watch the video, then complete the retrieval check below to unlock your spaced-recall cards.
How to use this sheet Toggle the toolbar above. Notes prints the full reference for review. Study prints as a fill-in-the-blank worksheet, print it, then write each definition while you watch the video or read your book. Quiz me is on-screen typing practice; type the term, click Reveal to check yourself.
- Name the layers of the epidermis from deepest to most superficial and the cell type that dominates each.
- Distinguish the papillary and reticular layers of the dermis and what each layer contains.
- Place hair follicles, sweat glands, blood vessels, and sensory receptors in the correct skin layer.
Epidermis (top down)
- Stratum corneumAnucleate keratin sheets: dead keratinocytes packed with keratin. Waterproof barrier.
- Stratum lucidumThick skin only: palms and soles. Translucent dead cells.
- Stratum granulosumKeratohyalin granules: keratinocytes start dying here, releasing lipids that seal the barrier.
- Stratum spinosum“Prickly” desmosomes: keratinocyte cohesion plus dendritic cells (immune surveillance).
- Stratum basaleMitotic engine: new keratinocytes born here. Melanocytes (pigment) and Merkel cells (touch) sit at this layer.
Dermis & hypodermis
- Papillary dermis (superficial)Loose areolar tissue: dermal papillae interlock with epidermis. Holds the capillary network that feeds the epidermis (which has no blood vessels of its own). · Meissner corpuscles: light touch receptors.
- Reticular dermis (deep)Dense irregular connective tissue: collagen and elastin web that gives skin its strength and rebound. · Hair follicles, sebaceous glands, sweat glands all live here. · Pacinian corpuscles: deep pressure and vibration receptors.
- Hypodermis (subcutaneous)Adipose + loose connective tissue: anchors skin to underlying fascia. Insulation, energy reserve, shock absorption. · Not technically part of skin but everything in skin attaches to it.
Step 3 . Retrieval check
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