Chapter 10 Skin Properties and Disorders

Skin Disorders and Conditions

• Acne: Chronic inflammation of sebaceous glands; causes include retained secretions.
• Anhidrosis: A condition marked by a deficiency or complete lack of perspiration.
• Bromhidrosis: Foul-smelling perspiration, often resulting from bacterial breakdown of sweat.
• Eczema: Inflammatory skin condition causing painful itching and lesions that can be dry or moist.
• Ivy dermatitis: Inflammation triggered by contact with poison ivy or related plants.
• Psoriasis: Characterized by red patches covered with silvery-white scales.
• Vitiligo: Acquired leukoderma resulting in milky-white skin spots.

Types of Skin Cancer

• Basal cell carcinoma: The most common and least severe type of skin cancer.
• Squamous cell carcinoma: More serious than basal cell carcinoma but not as severe as malignant melanoma.
• Malignant melanoma: The most severe form of skin cancer, known for its aggressive nature and tendency to spread.

Skin Anatomy

• Adipose tissue: Also known as subcutaneous tissue; serves as a cushion beneath the dermis.
• Dermis: The inner layer of skin, often referred to as corium or true skin, containing important structural components.
• Epidermis: Outermost skin layer, often called the cuticle or scarf skin, providing a protective barrier.
• Sebaceous glands: Oil-producing glands connected to hair follicles.

Skin Structures and Functions

• Collagen: A fibrous protein providing form and strength to the skin.
• Elastin: A protein similar to collagen that contributes to the skin's elasticity.
• Keratoma: Technical term for a callus, often resulting from friction or pressure.
• Cicatrix: Medical term for a scar, indicating the result of tissue healing.

Skin Conditions Related to Pigmentation

• Albinism: Congenital lack of melanin pigment in the body.
• Chloasma: Non-elevated spots caused by increased pigmentation in skin.
• Lentigines: Technical term for freckles, commonly harmless skin discolorations.
• Leukoderm: Abnormal white patches on the skin.

Skin Lesions and Abnormalities

• Bulla: A large blister filled with watery fluid.
• Papule: A small, raised lesion, often referred to as a pimple.
• Pustule: An inflamed pimple containing pus.
• Vesicle: A small blister containing clear fluid, distinct from a bulla.

Skin Disorders Related to Oil and Sweat

• Asteatosis: Condition of dry, scaly skin due to insufficient sebum production.
• Seborrhea: Excessive secretion of sebum, leading to oily skin and potential acne formation.
• Hyperhidrosis: Excessive sweating, impacting body temperature regulation.

Other Skin-Related Terms

• Macule: A flat discoloration on the skin, such as common freckles.
• Scale: Accumulation of dry or greasy flakes on the skin.
• Ulcer: An open skin lesion marked by pus and erosion due to infection or malignancy.
• Wheal: An itchy, swollen lesion often caused by insect bites or plant irritation.

Nerve Fibers in the Skin

• Motor nerve fibers: Distributed to the arrector pili muscles associated with hair follicles, involved in hair movement.
• Sensory nerve fibers: Respond to stimuli such as heat, cold, and pressure, sending signals to the brain.
• Secretory nerve fibers: Regulate perspiration and sebum flow from glands.

General Definitions

• Cyst: A closed sac containing fluid or diseased material located above or below the skin.
• Tumor: Abnormal growth resulting from excessive cell multiplication.
• Crust: Accumulated dead cells forming over a wound, impacting healing.