Anatomy and physiology of friction ridge skin lecture 1

Skin

The largest organ of the body composed of three layers.

Temperature regulation

A function of skin that helps maintain body temperature through insulation and cooling.

Epidermis

The outermost layer of skin that prevents water loss via evaporation.

Dermis

The middle layer of skin primarily made of connective tissues that nourish the skin.

Hypodermis

The innermost layer of skin consisting of loose connective tissue and fat, providing energy reserves.

Friction ridge skin

Skin with surface-level ridges rooted in the dermis, important for grip.

Keratinocytes

Primary cells of the epidermis, making up 90-95% of its cells, involved in cell differentiation.

Melanocytes

Cells in the epidermis that produce melanin, protecting genetic material from UV damage.

Langerhans cells

Immune cells in the epidermis that recruit T cells to attack invaders.

Merkel cells

Sensory cells in the epidermis that play a role in the sensation of touch.

Stratum basale

The deepest layer of the epidermis where cell division occurs.

Stratum corneum

The outermost layer of the epidermis, consisting of dead keratinized cells.

Papillary layer

The upper layer of the dermis made of loose connective tissue containing fibrils and dermal cells

Reticular layer

The deeper layer of the dermis made of compact connective tissue containing collagen and elastic fibers.

Dermal papillae

Finger-like projections in the dermis that interlock with the epidermis.

Anastomoses

Tissue sheets formed from the epidermis that cross-link near primary and secondary ridges.

Meissner corpuscles

Sensory receptors in the dermis responsible for the sensation of touch.

Ruffini corpuscles

Sensory receptors in the dermis that detect pressure.

Pacinian corpuscles

Sensory receptors in the dermis that respond to deep pressure and vibration.

Eccrine sweat glands

Glands that produce sweat primarily composed of water, salt, and other substances.

Basement membrane

A fibrous sheet that attaches the basal keratinocytes of the epidermis to the underlying dermis.

Gap junctions

Connections between adjacent cell membranes that allow direct exchange of small molecules and ions.

Cell surface receptors

Modified proteins on the outer membrane that respond to signals from other cells.

Wound healing phases

Inflammation, proliferation, and tissue remodeling are the three phases of skin healing.

Aging of friction ridge skin

Characterized by flattening of ridges and loss of elasticity, leading to wrinkles.