General Anatomy and Structure of the Skin

Comprehensive vocabulary flashcards covering the anatomical structure, layers, modifications, and physiological functions of animal skin.

Skin

The external covering of the body that protects against injury, participates in temperature control, and responds to diverse external stimuli through its numerous nerve endings.

Skin folds and creases

Areas where the skin appears redundant rather than closely molded to underlying structures, serving to accommodate changes in posture, increase surface area for heat dissipation, or reflect breeders' whims.

Epidermis

The outer layer of the skin, composed of a stratified squamous epithelium that rapidly adapts its thickness to rough usage and friction.

Calluses

Local epidermal thickenings that develop rapidly in response to rough usage, such as those found on human palms and soles.

Dermis

The inner layer of skin, consisting essentially of felted connective tissue fibers that constitute the raw material of leather, richly supplied with cutaneous nerves and blood vessels.

Subcutis

A layer of looser connective tissue underlying the dermis upon which the skin rests in most situations; also designated as the hypodermis or superficial fascia.

Interlocking papillae

Structural interdigitations securing the dermis to the epidermis, which are most pronounced where normal physical wear risks separation of the two layers.

Sweat glands

Epidermal modifications that function primarily to facilitate heat loss through surface evaporation, while serving a subsidiary role in the excretion of waste.

Sebaceous glands

Epidermal glands that secrete an oily substance that waterproofs the skin surface and imparts a characteristic sheen to relatively hairless regions such as the groin of horses.

Hair coat

An uniquely mammalian epidermal modification that provides mechanical protection and serves as a thermal insulator through the entrapment of air within its pile.

Flaying

The process of stripping skin from a carcass, which is made easier because the skin moves freely over underlying tissues across most of the body.

Synovial bursae

Protective fluid-filled structures that often develop adventitiously over bony prominences where the dermis is subjected to the risk of pressure injury.

Block of skin (Figure 1–4)

A schematic block section depicting: 1. Epidermis, 2. dermis, 3. subcutis, 4. sebaceous gland, 5. arrector pili muscle, 6. sweat gland, 7. hair follicle, and 8. arterial networks.