BIO Identify skin strcures and strata dermis layer

Epidermis

Thin, outermost layer; appears as the top surface of the skin.

dermis

 Thick layer directly underneath the epidermis; contains most of the skin structures.

Hypodermis

 Deep layer underneath the dermis; appears loose and often contains large clusters of fat.

Adipose Tissue

 Large, round/empty-looking cells; often appears like bubbles or honeycomb.

melanocytes

 Small dendrite-looking cells located near the bottom of the epidermis (stratum basale); often difficult to see individually.

dermal papillae

Small, finger-like projections along the epidermis–dermis boundary.

Merkel cells

Small cells in the stratum basale; sensory nerve

Pacinian corpuscles = lamellated corpuscles

 Large, round or oval structures with concentric layers, giving an onion-like appearance; usually deep in the dermis/hypodermis.

Sweat glands = sudoriferous glands

Coiled/twisted tubular structures, usually found in the dermis.

sebaceous glands

 Small clusters of sac-like cells attached to or near a hair follicle.

hair follicles

 Long, tube-like structures surrounding the base/root of a hair.

arrector pili

Thin bands of smooth muscle running from a hair follicle toward the upper dermis

papillary layer of dermis

Thin, upper portion of the dermis, directly beneath the epidermis.

reticular layer of derm

Thicker, deeper portion of the dermis; contains many glands, follicles, vessels, and connective tissue fibers

blood vessels.

Thin, tube-like structures within the dermis; often seen as small branching vessels.

stratum germinativum (stratum basale)

• Deepest epidermal layer.

• Single layer of cells next to the dermis.

• Cells are usually small and dark.

• Contains basal cells, melanocytes, and Merkel cells.

stratum spinosum

stratum granulosum,

• Located above the stratum basale.

• Several layers of cells.

• Cells appear spiky or prickly under a microscope.

stratum lucidum

• Thin, clear-looking layer.

• Found only in thick skin.

• Located between the granulosum and corneum.

stratum corneum.

• Outermost layer.

• Thick layer of flattened, dead cells.

• Appears as many thin, flat layers at the surface.