Integumentary System

Epidermis

• The top layer of your skin. This is the part of your skin that you can see and touch.

• It’s made up of three types of cells: melanocytes, keratinocytes and Langerhans.

• It gives your skin its color and provides a waterproof barrier.

Dermis

The middle layer of your skin. This layer is the thickest. It contains sweat and oil glands and hair follicles.

Hypodermis

The bottom layer of your skin. It’s the fatty layer of your skin that helps insulate your body.

Sweat glands

are tubular structures that produce sweat, the secretion of which one of the body's mechanisms to cool itself.

Nails

• serve for the protection of the fingertips and the surrounding soft tissues against accidents or injuries.

• increase the capability of our fingers for precise movements because they provide counter- pressure on the pulp of the fingertips.

Sebaceous glands

microscopic exocrine glands that produce and secrete sebum, an oily substance that lubricates skin and hair, and are typically located in the dermis, often associated with hair follicles. 

Hair follicle

• for producing and sustaining hair growth.

• This structure also contributes to various skin functions and responses.

• are crucial in wound healing and skin regeneration

Dermatitis

a general term for skin inflammation, can manifest as itching, redness, and various skin issues, often stemming from allergies or irritants.

Melanoma

which can develop from previously benign moles or healthy skin

Basal cell carcinoma

which initially appears as a waxy bump or a flat lesion that is flesh- or brown-colored

Squamous cell carcinoma,

which usually occurs on body parts exposed to the sun, such as the hands and face

Kaposi sarcoma

which develops in the blood vessels and affects people with compromised immune systems

Merkel cell carcinoma

seen as firm bumps on or beneath the skin, as well as in hair follicle

1st degree

Affects only the epidermis (the outer layer of skin)

2nd degree

Affects both the epidermis and part of the dermis (the middle layer).

3rd degree

Destroys both the epidermis and dermis, possibly affecting the hypodermis (subcutaneous layer) as well.

4th degree

extends through the skin layers into underlying tissues like muscles, tendons, and bones.

Stratum Corneum

Composed of dead, flattened skin cells (keratinocytes) filled with keratin. This layer forms a tough barrier that protects against physical damage, pathogens, and dehydration.

Stratum lucidum

Provides an extra layer of protection in areas subject to friction, like palms and soles, making the skin tougher and more resilient.

Stratum Granulosum

Cells here start to die and become more flattened. They release lipids (fats) that form a barrier to help keep the skin hydrated and protect from harmful substances.

Stratum spinosum

This layer has living cells that provide strength and flexibility. The cells here contain structures called desmosomes, which hold cells together tightly to prevent them from being pulled apart.

Stratum basale

• The deepest layer, where new skin cells (keratinocytes) are created. These cells continuously divide and move upward to replace the older cells that shed from the surface.

• Contains melanocytes, which produce melanin, the pigment responsible for skin color and UV protection.