Skin Structures and Functions

Study Notes

Skin Structures

Skin structures are formed by epithelial cells and are located in the dermis.
Structures include hair, nails, and glands: sweat, sebaceous, and mammary.

Hair

Composed of keratin-filled cells except for the hair bulb.
Found on the scalp, armpits, and groin in humans.
Provides thermal insulation in mammals.
Hair bulb: Contains cells responsible for hair growth and is nourished by blood vessels.

Nails

Composed primarily of keratin.
Protect fingertips and enhance the sense of touch.

Glands

Sebaceous glands: Produce sebum, an oily substance that lubricates and waterproofs the skin and hair.
Sweat glands: Produce sweat, which helps regulate body temperature.
Mammary glands: Produce milk for nourishing offspring in mammals.

Skin Structure

Skin is the largest organ in the human body.
It covers approximately 2 square meters and weighs about 15% of an adult's body mass.
Skin has two layers: the epidermis and the dermis.
Beneath the skin is subcutaneous tissue.

Epidermis and Dermis

The epidermis is the outermost layer of the skin and provides protection from external factors.
It consists of stratified squamous epithelium.
The dermis is the layer underneath the epidermis and contains connective tissue, blood vessels, glands, and hair follicles.
The dermis's connective tissue provides strength and elasticity.
Blood vessels in the dermis supply nutrients and remove waste products from the skin.
Glands in the dermis include sebaceous glands, which secrete oil, and sweat glands, which secrete sweat.

Subcutaneous Tissue

Subcutaneous tissue lies beneath the dermis.
It is composed of adipose tissue, also known as fat, and loose connective tissue.
This layer provides insulation, cushioning, and energy storage.
It also contains blood vessels and nerves that supply the skin.

Epidermis

The epidermis is the outermost layer of skin, composed of stratified squamous epithelium.
Stratified Squamous Layer (Stwardniały): This layer is hardened by keratin deposition, forming a protective barrier against environmental factors and preventing water loss.
Reproductive Layer (Rozrodcza): This layer is responsible for cell division and regeneration, continuously replenishing the Stratified Squamous Layer.
The stratum corneum (Stratified Squamous Layer) continually flakes off.
Melanocytes within the epidermis produce melanin, which protects the skin from harmful ultraviolet radiation.
The amount of melanin determines skin color.

Dermis

The dermis is a thicker layer than the epidermis, primarily composed of fibrous connective tissue containing collagen fibers.
Collagen fibers provide the dermis with mechanical strength, elasticity, and extensibility.
The dermis contains numerous blood vessels that remove metabolic waste and regulate body temperature.
Sensory receptors in the dermis receive external stimuli and transmit information to the nervous system.

Hypodermis

The hypodermis, primarily adipose tissue, performs several functions.
Thermal insulation: Prevents heat loss.
Shock absorption: Cushions against physical impacts.
Energy reserve: Stores energy.
The thickness of the hypodermis and its fat content are influenced by body location, gender, and nutritional status.

Description

Explore the intricate structures of the skin, including hair, nails, and various glands. This quiz delves into the composition, functions, and importance of these skin structures in protecting the body and maintaining temperature regulation. Test your knowledge about how these components interact and contribute to overall skin health.