Ch 5 - Pt 1: Integumentary System (Skin)

Vocabulary flashcards covering the components, cell types, epidermal layers, dermal structures, and color pigments of the integumentary system based on lecture slides.

Integumentary System

The organ system consisting of the skin, sudoriferous (sweat) glands, sebaceous (oil) glands, hairs, nails, and subcutaneous tissue.

Epidermis

The outermost protective shield of the body, consisting of avascular epithelial tissue.

Dermis

The vascular layer underlying the epidermis that makes up the bulk of the skin, composed mostly of dense connective tissue.

Subcutaneous Tissue

Also called the hypodermis or superficial fascia; tissue composed mostly of adipose and some areolar connective tissue that loosely anchors skin to underlying muscles, absorbs shock, and provides insulation.

Keratinocytes

The major cell type of the epidermis that produces fibrous keratin, providing protective properties; millions slough off daily to renew the epidermis every 25 to 45 days.

Melanocytes

Spider-shaped cells located in the deepest epidermis that produce melanin and package it into melanosomes to protect keratinocyte nuclei from UV damage.

Dendritic Cells

Also known as Langerhans cells; star-shaped macrophages patrolling the deep epidermis that ingest foreign substances and act as key activators of the immune system.

Tactile Epithelial Cells

Also known as Merkel cells; sensory receptors for touch located at the epidermal-dermal junction.

Stratum Basale

The deepest layer of the epidermis, firmly attached to the dermis and consisting of a single row of actively mitotic stem cells; also known as stratum germinativum.

Stratum Spinosum

The prickly layer of the epidermis, several cell layers thick, containing keratinocytes with a web-like system of intermediate pre-keratin filaments attached to desmosomes.

Stratum Granulosum

The granular layer of the epidermis, four to six cells thick, where cells flatten, nuclei and organelles disintegrate, and keratinization begins with keratohyaline and lamellar granules.

Stratum Lucidum

The clear layer of the epidermis found only in thick skin, consisting of a thin translucent band of two to three rows of clear, flat, dead keratinocytes superficial to the stratum granulosum.

Stratum Corneum

The horny outer layer of the epidermis, consisting of 20 to 30 rows of flat, anucleated, keratinized dead cells, accounting for three-quarters of epidermal thickness.

Papillary Dermis

The thin, superficial layer of the dermis made of areolar connective tissue with loose collagen and elastic fibers, blood vessels, and dermal papillae.

Dermal Papillae

Fingerlike projections from the superficial region of the dermis into the epidermis that contain capillary loops, free nerve endings, and tactile corpuscles (Meissner's corpuscles).

Friction Ridges

Epidermal ridges lying on top of dermal ridges formed by dermal papillae in thick skin that enhance gripping ability and amplify touch sensations.

Reticular Dermis

The deeper dermal layer making up approximately 80% of dermal thickness, composed of coarse, dense irregular connective tissue with collagen and elastic fibers.

Dermal Vascular Plexus

A network of blood vessels located between the reticular dermis and the subcutaneous tissue.

Cleavage Lines

Externally invisible tension lines in the reticular dermis caused by collagen fiber bundles running parallel to the skin surface; surgical incisions parallel to these lines heal more readily.

Flexure Lines

Dermal folds located at or near joints where the dermis is tightly secured to deeper structures, creating deep creases visible on hands, wrists, fingers, soles, and toes.

Striae

Silvery white scars, commonly called stretch marks, caused by extreme stretching of the skin that results in dermal tearing.

Blisters

Fluid-filled pockets separating the epidermal and dermal layers caused by acute short-term trauma such as burns or repeated friction.

Melanin

The only pigment synthesized directly in the skin by melanocytes; packaged in melanosomes to shield keratinocyte DNA against UV radiation.

Carotene

A yellow to orange pigment most obvious in the palms and soles that accumulates in the stratum corneum and subcutaneous tissue and can be converted to vitamin A.

Cyanosis

A bluish discoloration of the skin caused by low oxygenation of hemoglobin, indicating potential respiratory or cardiovascular issues.

Erythema

Redness of the skin caused by conditions such as embarrassment, fever, inflammation, or allergies.

Jaundice

A yellowing of the skin that serves as a clinical sign of liver disorders.

Hematomas

Red, purple, green, or yellow skin markings, commonly known as bruises, resulting from blood leaking from damaged blood vessels beneath the skin.

Skin Color Determination

The result of relative amounts and combinations of three pigments: melanin (synthesized in skin by melanocytes), carotene (ingested yellow-orange pigment), and oxygenated hemoglobin (in dermal blood vessels).