Integumentary System: Exocrine Glands, Dermal Layers, and Epidermal Characteristics

Vocabulary flashcards covering the exocrine glands of the skin, dermal papillary and reticular layers, dermal innervation and thermoregulation, and epidermal stratifications.

Sweat (sudoiferous) glands

Exocrine glands of the skin that produce a watery solution.

Merocrine glands

Sweat glands that secrete sweat to the axillary / perineal region / skin surface, where the opening of the duct is called a sweat pore.

Apocrine glands

Sweat glands that secrete sweat into hair follicles of the axillary + pubic region.

Sebaceous glands

Exocrine glands of the skin that produce oily secretions (oil).

Holocrine glands

Glands that secrete sebum into hair follicles or directly onto the skin surface.

Papillary layer

The superficial layer of the dermis adjacent to the epidermis, composed of areolar CT, containing dermal papillae, sensory receptors, and capillaries that supply nutrients to the epidermis via diffusion.

Dermal papillae

Projections of the dermis toward the epidermis that interlock with epidermal ridges, increasing the surface area between the epidermis + dermis.

Reticular layer

The deeper, thicker layer of the dermis composed of dense irregular CT, including many blood vessels, glands, hair follicles, & nerves.

Innervation

The property of nerve fibers being extensively dispersed in the dermis to monitor sensory receptors, control blood flow, and control glandular secretion.

Vasoconstriction

A response in dermal blood vessels that reduces blood flow to the skin to help conserve heat.

Vasodilation

A response in dermal blood vessels that increases blood flow to the skin to help release heat.

Stratum corneum

The most superficial stratum of the epidermis consisting of $20\text{-}30$ layers of dead, anucleate, and tightly packed cells that protect deeper layers before being shed.

Stratum basale migration

The process where cells from the stratum basale take about $2$ ext{ weeks} to migrate to the stratum corneum, where they spend another $2$ ext{ weeks} serving to protect deeper layers.

Thick skin

Skin type that contains $5$ layers in the epidermis (including stratum lucidum), is found in palms + soles, has an epidermis $4\text{-}.6\text{ mm}$ thick, and lacks hair follicles + sebaceous glands.

Thin skin

Skin type that contains $4$ layers in the epidermis (lacks stratum lucidum), covers most of the body, and has an epidermis $075\text{-}150\text{ mm}$ thick.