Integumentary System

Integumentary

The skin system, which is the largest organ in the body.

Epidermis

The superficial layer of skin composed of stratified squamous epithelial cells.

Melanocytes

Cells that produce pigment.

Tactile/Merkel cells

Cells that pick up touch senses.

Keratinocytes

Major skin cells of the epidermal layer that produce a tough fibrous protein called keratin.

Dendritic cells/Langerhan cells

Cells that help fight against pathogens.

Dermis

The second major region of the skin composed of flexible connective tissue.

Subcutaneous layer/Hypodermis

The bottom layer of the skin that stores fat and connects the skin to muscles and bones.

Thick skin

Found in palms, fingers, and soles of feet, with 5 layers of keratinocytes.

Thin skin

Found everywhere else in the body, with 4 layers of keratinocytes.

Collagen

Elastic fibrous proteins that make up the dermis, giving skin its strength and resilience.

Cleavage lines

Separations between underlying collagen fiber bundles in the reticular dermis that affect healing of surgical incisions.

Reticulum

A network or mesh of fibrils, fibers, or filaments.

Stratum Basale (Stratum Germinativum)

The deepest layer of the epidermis containing rapidly dividing keratinocytes.

Stratum Spinosum

Several layers of flattened and interconnected keratinocytes.

Stratum Granulosum

Contains flattened keratinocytes filled with keratohyalin granules.

Stratum Lucidum

Clear, translucent layer present only in thick skin.

Stratum Corneum

The outermost layer of the epidermis in thick skin composed of many layers of dead, fully keratinized cells.

Papillary

Resembling small, nipple-shaped projections or elevations found in clusters.

Hair

The outgrowth of skin composed of keratin.

Dermal papillae

Nipple-like projections of the dermis that may contain blood capillaries or touch receptors.

Cutaneous plexus

Deep network of arteries along the reticular layer.

Capillary loops

Tiny, thin-walled blood vessels responsible for the exchange of oxygen, nutrients, and waste products.

Adipocytes

Cells that make up adipose tissue, storing energy and providing insulation and cushioning.

Eccrine Gland

Sweat glands distributed throughout the skin that produce watery sweat to regulate body temperature.

Apocrine Gland

Sweat glands found in areas like the armpits and groin that produce thicker sweat containing proteins and can develop an odor.

Sebum

Oily, waxy substance produced by sebaceous glands to lubricate and protect the skin and hair.

Sudoriferous Gland

A general term for sweat glands, including both eccrine and apocrine glands.

Ceruminous Gland

Glands found in the ear canal that produce earwax to protect the ear and trap debris.

Mammary Glands

Specialized glands in the female breast that produce milk.

Melanoma

Aggressive skin cancer arising from melanocytes.

Melanin

Pigment responsible for skin, hair, and eye color, produced by melanocytes.

Melanosomes

Specialized organelles within melanocytes that contain melanin.

Dermcidin

Protein found in sweat with antimicrobial properties.

Subcutaneous Injection

Method of administering medication by injecting it into the subcutaneous tissue.

Holocrine Secretion

Mode of glandular secretion where entire cells, along with their contents, are released as a secretion.

Alveolar Glands

Glands with a structure resembling small sacs found in various parts of the body, including the mammary glands.

Accessory structures

Hair, nails, sweat glands, and sebaceous glands that are part of the skin.