BIOL2401 Exam 2 Study Guide: The Integumentary System

Flashcards covering key vocabulary terms from Chapter 5: The Integumentary System, including skin structure, functions, accessory organs, and common conditions.

Integumentary System

Organ system made up of the skin and its accessory organs (hair, nails, glands).

Functions of the Skin

Protection, sensation, temperature regulation, excretion, Vitamin D synthesis, immunity, water barrier (HIPEE RV).

Layers of the Skin

Epidermis (outermost), Dermis (middle), and Subcutaneous layer (Hypodermis - innermost, not technically part of the skin but closely associated).

Layers of Epidermis

Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (in thick skin), and stratum corneum. Cells flatten, keratinize, and die as they move from basale to corneum.

Melanocytes

Cells found in the stratum basale that produce melanin to protect against UV radiation.

Melanin

Pigment produced by melanocytes that determines skin color and offers UV protection.

Lines of Tension (Cleavage Lines)

Bundles of collagen and elastic fibers in the dermis; plastic surgeons make incisions parallel to these lines to promote faster healing and less scarring.

Decubitus Ulcers (Bedsores)

Skin lesions caused by sustained pressure on the skin, restricting blood flow; preventable by frequent repositioning, good hygiene, and proper nutrition.

Hair Structure

Composed of a shaft, root, and bulb, growing from a hair follicle; its color is determined by the type and amount of melanin produced.

Arrector Pili Muscle

Small muscle attached to the hair follicle; its contraction causes hair to stand upright, resulting in 'goose bumps'.

Eccrine Sweat Glands

Widely distributed sweat glands that produce watery sweat for thermoregulation via evaporation.

Apocrine Sweat Glands

Sweat glands found in axillary and anogenital regions, producing a thicker, viscous sweat that, when broken down by bacteria, causes body odor.

Nail Structure

Hard plate made of keratin, covering the distal phalanges; includes nail plate, nail bed, lunula, and cuticle (eponychium). Formed in the nail matrix.

First-Degree Burn

Damages only the epidermis; characterized by redness and pain, no blisters; superficial.

Second-Degree Burn

Damages the epidermis and part of the dermis; characterized by blisters, redness, and significant pain; accessory organs can assist in healing.

Third-Degree Burn

Damages the epidermis, dermis, and extends into the subcutaneous layer; nerve endings are destroyed so it may be painless; requires skin grafting.

Accessory Organs in Burn Healing

Hair follicles, sebaceous glands, and sweat glands (extending into the dermis) provide epithelial cells for regeneration, especially crucial in second-degree burns.

Cutaneous Carcinomas

Skin cancers including basal cell carcinoma and squamous cell carcinoma, originating from keratinocytes; generally less severe than melanoma, linked to sun exposure.

Basal Cell Carcinoma

Most common and least malignant type of skin cancer, originating from stratum basale cells; slow-growing, rarely metastasizes.

Squamous Cell Carcinoma

Second most common skin cancer, originating from keratinocytes of the stratum spinosum; grows faster than basal cell, can metastasize if untreated.

Cutaneous Melanoma (Malignant Melanoma)

Most dangerous type of skin cancer, originating from melanocytes; highly metastatic and resistant to chemotherapy; often linked to severe sunburns.

Alopecia

Hair loss.

Pruritus

Itching.

Pustule

Small, elevated lesion containing pus.

Vesicle

Small, fluid-filled blister.

Boil (Furuncle)

Painful, pus-filled bump under the skin caused by an infected hair follicle.

Cyst

Sac-like pocket of tissue containing fluid or other material.

Wart

Small, hard, benign growth on the skin, typically caused by a virus.

Ulcer

An open sore on an external or internal surface of the body, caused by a break in the skin or mucous membrane that fails to heal.

Urticaria (Hives)

A skin rash with itchy, red, raised bumps or welts.