anaphy chapter 5

What is the Integumentary System?

The system consisting of the skin and accessory structures such as hair, glands, and nails.

What are the major functions of the Integumentary System?

The major functions of the integumentary system include:

1. Protection
2. Sensation
3. Vitamin D production
4. Temperature regulation
5. Excretion

Describe the Epidermis.

The most superficial layer of skin, composed of stratified squamous epithelium, that prevents water loss and resists abrasion.

What is keratinization?

The process where epidermal cells change shape and chemical composition, becoming filled with the protein keratin.

List the strata (layers) of the epidermis from deepest to most superficial.

The layers of the epidermis are:

1. Stratum basale
2. Stratum spinosum
3. Stratum granulosum
4. Stratum lucidum
5. Stratum corneum

What is the Stratum basale?

The deepest layer of the epidermis where cells undergo mitotic division about every 19 days.

What is the Stratum spinosum?

The epidermal layer where cells take on a flattened appearance and accumulate lipid-filled vesicles called lamellar bodies.

What is the Stratum granulosum?

The epidermal layer consisting of flat, diamond-shaped cells that accumulate more keratin and release the contents of lamellar bodies to the extracellular space.

What is the Stratum lucidum?

A clear zone found between the stratum granulosum and stratum corneum, typical in "thick skin".

What is the Stratum corneum?

The most superficial stratum of the epidermis.

What is "Thick skin"?

Skin found on the palms, soles of the feet, and fingertips, characterized by the presence of stratum lucidum.

Describe the Dermis.

Composed of dense collagenous connective tissue, containing fibroblasts, adipocytes, and macrophages.

What gives the dermis its strength?

The collagen and elastic fibers within the dermis are responsible for its strength.

What are Cleavage lines?

(Tension lines) Areas of the skin that are most resistant to stretch, along which surgical incisions are often made.

What are Stretch marks?

Marks on the skin caused by overstretched dermis, leading to tearing of collagen and elastic fibers.

What are Papillae in the dermis?

Projections in the upper part of the dermis (dermal papillae) that extend into the epidermis.

What are Friction ridges?

Curving ridges that shape the overlying epidermis into patterns, such as fingerprints.

What is an Intradermal injection?

A shallow injection angle into the dermis, exemplified by the tuberculin skin test.

What is a Subcutaneous injection?

An injection method involving pinching the skin to form a tent and inserting the needle into the adipose tissue of the subcutaneous layer, like an insulin injection.

What is an Intramuscular injection?

An injection method that delivers material to the blood faster using a 90-degree angle.

What is Melanin?

A group of pigments primarily responsible for skin, hair, and eye color, produced by melanocytes.

What is Albinism?

A recessive genetic trait that causes a deficiency or complete absence of melanin.

What is Cyanosis?

A bluish discoloration of the skin, often indicating poor oxygenation.

What is Carotene?

A yellow pigment found in plants that can accumulate in the stratum corneum and subcutaneous tissue, giving a yellowish tint to the skin.

Describe the Subcutaneous tissue.

(Hypodermis) The tissue layer under the dermis that is not part of the skin itself, which attaches the skin to bone and muscle.

List the main parts of a hair.

Hair follicle, shaft, root, hair bulb, cortex, cuticle, medulla, hair papilla.

What is the typical growth and rest cycle for scalp hair?

Scalp hair grows for 30 days and rests for 1-2 years.

What are Sebaceous glands?

Hairless glands that produce an oily substance (sebum) to lubricate skin and hair.

Describe Eccrine sweat glands.

Sweat glands that produce a watery secretion (merocrine secretion) for temperature regulation.

Describe Apocrine sweat glands.

Larger sweat glands found in the axillary and genital areas that produce a thicker secretion rich in organic substances.

What are Nails?

Thin, hard plates covering the distal ends of fingers and toes.

List the main parts of a nail.

The parts of a nail typically include the free edge, nail body, lunula, cuticle, nail root, and nail matrix.

What are First-degree burns?

Burns that damage only the epidermis, causing redness, pain, and slight swelling.

What are Second-degree burns?

Burns that damage both the epidermis and dermis, causing redness, pain, swelling, and blistering.

What are Third-degree burns?

Burns that destroy the epidermis, dermis, and underlying tissue, often appearing white, tan, brown, black, or deep cherry red, with little pain.

What are Fourth-degree burns?

Burns that damage tissue deeper than the subcutaneous layer, potentially involving muscle and bone.