Integument Structure and Function in Vertebrates

Integument (Skin)

The outer covering of the body, also known as the cutaneous layer.

Epidermis

Superficial layer of skin.

Basement membrane

Separates epithelium from connective tissue.

Dermis

Deep layer of skin.

Hypodermis

Layer of connective tissue under the skin; also called superficial fascia or subcutaneous layer.

Integument Functions

Includes protection, shape maintenance, osmotic control, gas exchange, temperature regulation, and sensory functions.

Chromatophores

Skin pigment cells that provide color to the organism.

Dermal bones

Plates of bone initially positioned in the dermis.

Keratinization

Process by which proteins form keratin with help from keratinocytes.

Stratum corneum

Outer keratinized layer of the epidermis in terrestrial vertebrates.

Callus

A thick protective layer that can form on the skin.

Epidermal cells

Cells in the epidermis that include various types such as club cells and goblet cells.

Cosmoid scales

Scales made from enamel, dentin, and bone found in some fish.

Amphibian skin

Specialized for cutaneous respiration and lacks scales.

Mucus glands

Glands in the dermis of amphibians that produce mucus.

Gastralia

Bones in the abdominal area of some reptiles.

Uropygial gland

Gland at the base of the tail in birds that produces a lipid/protein product.

Salt gland

Gland on the head of some birds that excretes excess salt.

Langerhans cells

Cells in the epidermis that assist in immunity.

Papillary layer

Upper layer of the dermis made from dermal papillae.

Sebaceous glands

Glands that produce oily secretion (sebum) released into hair follicles.

Nail

Plate of tightly compacted, cornified epithelial cells on the surface of fingers and toes.

Horn

Tough, cornified sheath that fits over a bony core and is never branched.

Baleen

Plate that acts as a strainer for whales, made from integument.

Integument

Skin, also known as the cutaneous layer.

Functions of integument

Forms part of exoskeleton, protects entry of microbes, helps hold shape of organism, regulates osmotic control and gas exchange, controls temperature, senses stimuli, and provides color through chromatophores.

Ganoid scales

Reduced scales in teleost fishes, mostly made of lamellar bone.

Cutaneous respiration

Specialized skin function in amphibians for gas exchange.

Ecdysis

Molting process in reptiles.

Merkel cells

Cells associated with nerve endings that detect light touch and pressure.

Eccrine glands

Sweat glands found in humans but not in all mammals.

Mammary glands

Glands that produce milk.

Claw

Curved, laterally compressed keratinized projections from the tips of digits.

Hoof

Enlarged keratinized plate on the tips of ungulate digits.

Antlers

Branched bone; finished antlers have shed their 'velvet', the integument.

5 layers of the epithelium in mammals

stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale