The Integumentary System Flashcards

Flashcards related to the integumentary system, covering functional anatomy of the skin, accessory structures, and clinical aspects based on lecture notes.

Integumentary system

The skin and various accessory structures such as hair, nails, and glands.

Epidermis

Composed of stratified squamous epithelium.

Dermis

Composed of Papillary layer (areolar connective tissue) and Reticular layer (dense irregular connective tissue).

Accessory structures of the skin

Hairs, Nails, Exocrine glands (Sebaceous glands and Sweat glands), Sensory receptors and nerve fibers, Arrector pili muscles, Cutaneous plexus (network of blood vessels).

Functions of the Integumentary System

Protects underlying tissues and organs; Excretes salts, water, and organic wastes; Maintains body temperature; Produces melanin, keratin, and vitamin D3; Stores lipids; Detects touch, pressure, pain, and temperature.

Epidermis Composition

Multiple layers of epidermal cells. Primary cell type is keratinocyte, which are arranged in strata (layers).

Thin skin

Covers most of the body surface and contains four strata (layers).

Thick skin

Found on the palms of the hands and soles of the feet and contains five strata (layers).

Fingerprints

Pattern of epidermal ridges on the surface of fingertips; unique pattern used to identify individuals.

Epidermal layers (deep to superficial)

Stratum basale, Stratum spinosum, Stratum granulosum, Stratum lucidum, Stratum corneum.

Carotene

Orange-yellow pigment.

Melanin

Brown, yellow-brown, or black pigment produced by melanocytes in stratum basale.

Basal cell carcinoma

Most common form of skin cancer; originates in stratum basale due to mutations caused by overexposure to UV radiation.

Malignant melanoma

Extremely dangerous; cancerous melanocytes; grow rapidly and metastasize through lymphatic system.

Two types of fibers in the dermis

Collagen fibers and Elastic fibers.

Papillary layer of the dermis

Composed of areolar tissue and contains capillaries, lymphatic vessels, and sensory neurons.

Reticular layer of the dermis

Interwoven meshwork of dense, irregular connective tissue with collagen and elastic fibers; contains blood vessels, lymphatic vessels, nerve fibers, and accessory organs.

Burns

Result from exposure to heat, friction, radiation, electrical shock, or strong chemical agents.

First-degree burn

Only the surface of the epidermis is affected; example: most sunburns.

Second-degree burn

Entire epidermis and maybe some of the dermis are damaged; accessory structures not affected; blistering, pain, and swelling occur.

Third-degree burn

Destroys epidermis, dermis, and damage extends into subcutaneous layer.

Rule of nines

Method of estimating percentage of surface area affected by burns.

Split-thickness graft

Transfer of epidermis and superficial portions of dermis.

Full-thickness graft

Transfer of epidermis and both layers of dermis.

Autograft

Patient’s own undamaged skin.

Allograft

Frozen skin from a cadaver.

Xenograft

Animal skin

Epidermal derivatives

Originate from epidermis during embryological development.

Hair follicles

Produce hairs that protect the skull and provide delicate touch sensations.

Exocrine glands

Sweat glands (assist in thermoregulation and excrete wastes) and Sebaceous glands (lubricate epidermis).

Nails

Protect and support tips of fingers and toes.

Terminal hairs

Large, coarse, darkly pigmented hairs found on the scalp or in the armpit.

Vellus hairs

Smaller, shorter, delicate hairs found on the general body surface.

Hair shaft

Begins deep within hair follicle, but can be seen on the surface.

Hair root

Anchors the hair into the skin; extends from base of follicle to point where hair shaft loses connection with follicle walls.

Root hair plexus

Collection of sensory nerves surrounding the base of the follicle.

Arrector pili

Smooth muscle attached to hair follicle; contraction pulls hair erect.

Hair bulb

Expanded base of hair follicle.

Hair papilla

peg of connective tissue filled with blood vessels and nerves.

Hair matrix

Actively dividing basal cells in contact with hair papilla.

Medulla

Layer of daughter cells formed at the center of the matrix.

Cortex

Intermediate layer deep to the cuticle.

Cuticle

Daughter cells produced at edges of the matrix; forms surface of the hair.

Sebaceous glands

Holocrine glands that discharge an oily lipid secretion.

Sebum

Oily lipid secretion; mixture of triglycerides, cholesterol, proteins, and electrolytes; lubricates hair shaft and is antimicrobial.

Sweat glands

Produce watery secretion by merocrine secretion; function to wash epidermal surface.

Apocrine sweat glands

Found in axillae, around nipples, and in pubic region; produce sticky, cloudy, odorous secretion with complex composition; strongly influenced by hormones.

Eccrine/merocrine sweat glands

Secrete directly onto surface of the skin; most numerous on palms and soles; produce watery secretions with electrolytes; important in thermoregulation and excretion.

Nails

Thick sheets of keratinized epidermal cells; protect exposed dorsal surfaces of tips of fingers and toes; help limit distortion of digits under physical stress.

Nail body

Visible portion of nail.

Nail root

Epidermal fold where nail production occurs.

Eponychium

Portion of stratum corneum of nail root extending over exposed nail; also known as cuticle.

Hyponychium

Area of thickened stratum corneum under free edge.

Inflammation phase of skin regeneration

Initial injury causes bleeding and mast cell activation; produces swelling, redness, heat, and pain.

Migration phase of skin regeneration

Blood clot (scab) forms at surface; cells of stratum basale divide and migrate along wound edges; macrophages remove debris and pathogens; granulation tissue forms if damage into dermis.

Proliferation phase of skin regeneration

Scab undermined by migrating epidermal cells; phagocytic activity almost complete; blood clot disintegrating; fibroblasts have formed collagen fibers and ground substance.

Scarring phase of skin regeneration

Scab is shed; epidermis is complete; shallow depression marks injury site; fibroblasts continue to create scar tissue.