Integumentary System Flashcards

A set of vocabulary flashcards defining key structures, layers, cellular components, conditions, and glands of the integumentary system based on the lecture notes.

Integumentary System

A body system whose name comes from 'integumentum' (meaning a covering) that encloses internal structures, protects from external hazards and microbes, prevents dehydration, maintains electrolyte balance, synthesizes vitamin D, contains sensory receptors, and regulates temperature.

Epidermis

The most superficial layer of the skin, consisting of $4$ layers in thin skin and $5$ layers in thick skin.

Dermis

The middle layer of skin containing nerves, blood and lymph vessels, glands, and hair, composed of a papillary layer and a reticular layer.

Hypodermis

Also known as the subcutaneous layer; composed of adipose connective tissue for energy storage, which acts as a shock absorber for organs, reduces friction between skin and muscle/bone, and regulates body temperature.

Stratum basale

Layer $4$ (base layer) of the epidermis that attaches to the dermis via dermal papillae, serves as the site where new cells divide, and contains tactile cells and melanocytes.

Stratum spinosum

Layer $3$ of the epidermis, characterized by a spiny appearance due to desmosomes; it marks the start of keratinization and waterproofing, and contains keratinocytes, water-repelling glycolipids, and resident macrophages.

Stratum granulosum

Layer $2$ of the epidermis, characterized by a grainy appearance, where cells produce keratohyalin protein marking the start of keratinization.

Stratum lucidum

Layer $1.5$ of the epidermis, transparent in appearance and found in the palms of hands and soles of feet to reduce friction between the stratum corneum and stratum granulosum.

Stratum corneum

Layer $1$ (superficial layer) of the epidermis, composed of fully dead, keratinized cells (cornification) that protect the body from bacteria and dehydration.

Melanoma

A type of skin cancer characterized by Asymmetry, irregular Borders, varied Color shades, a Diameter larger than $0.24\text{ inch}$, and Evolving features.

Papillary layer

A layer of the dermis that provides structural and nutritional support to the epidermis and attaches to it via dermal papillae.

Reticular layer

A layer of the dermis made of dense, irregular connective tissue.

Hair

Filaments of keratinized cells composed of a follicle (bulb, root, and shaft) and connected to the arrector pili muscle.

Arrector pili

A smooth muscle attached to the hair follicle that causes goosebumps.

Nails

Structures covering the tips of fingers and toes that protect from mechanical stress, enhance sensitivity, and assist in picking up small objects.

Eccrine sweat glands

Skin glands that produce watery secretions.

Apocrine sweat glands

Skin glands that produce thick, oily secretions.

Sebaceous gland

A skin gland that secretes sebum (oil).

Ceruminous gland

A specialized gland in the skin that produces ear wax.

Mammary glands

Specialized glands in the integumentary system that produce milk.