Anatomy Chapter 5: Integumentary System

Questions and Answers

What is the integumentary system?

Bones and joints

Muscles of the body

The comprehensive system of the digestive tract

Skin, hair, and nails that provide an external protective covering (correct)

What is the epidermis?

The superficial layer of the skin composed of keratinized stratified squamous epithelium.

What are the four types of cells populating the epidermis?

Keratinocytes, melanocytes, dendritic cells, and tactile cells.

What do keratinocytes produce?

Keratin, a fibrous protein that helps provide protective properties to the epidermis, hair, and nails. Signup and view all the answers

What do melanocytes synthesize?

The pigment melanin. Signup and view all the answers

What are dendritic cells known for?

They are protective cells that phagocytize antigens and present them to T cells. Signup and view all the answers

What are tactile cells associated with?

Sensory nerve endings. Signup and view all the answers

What are the five layers of the epidermis from deep to superficial?

Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum. Signup and view all the answers

What is the stratum basale?

The deepest layer of the epidermis consisting of a single layer of cuboidal keratinocytes. Signup and view all the answers

What is the stratum spinosum?

The prickly layer that contains several layers of keratinocytes unified by desmosomes. Signup and view all the answers

What happens in the stratum granulosum?

Keratinization begins, and cells accumulate keratohyaline and lamellar granules. Signup and view all the answers

What are keratohyaline granules?

They help to form keratin in the upper layers of the skin. Signup and view all the answers

What do lamellar granules contain?

A water-resistant glycolipid. Signup and view all the answers

What is the stratum lucidum?

A clear layer above the stratum granulosum, found in areas where the skin is thickest. Signup and view all the answers

What characterizes the stratum corneum?

The outermost layer with dead, keratinized cells held together by desmosomes. Signup and view all the answers

What makes up the dermis?

A tough, leathery layer composed mostly of fibrous connective tissue. Signup and view all the answers

What are the two layers of the dermis?

Papillary layer and reticular layer. Signup and view all the answers

What characterizes the papillary layer?

It extends up to the epidermis to supply blood and remove waste. Signup and view all the answers

What characterizes the reticular layer?

A deeper layer with more fibers and a more organized structure. Signup and view all the answers

What are the three pigments that contribute to skin color?

Melanin, carotene, and hemoglobin. Signup and view all the answers

How does skin color vary?

It reflects the amount of melanin made and retained. Signup and view all the answers

Study Notes

Integumentary System Overview

Comprises skin, hair, and nails; serves as the body's external protective covering.

Epidermis

Superficial skin layer primarily made of keratinized stratified squamous epithelium; nutrients diffuse from dermis through tissue fluid.

Epidermal Cells

Four key cell types:
- Keratinocytes: Produce keratin, providing protection and water resistance.
- Melanocytes: Spider-shaped cells in the deepest epidermal layer that synthesize the pigment melanin.
- Dendritic Cells: Star-shaped cells from bone marrow that phagocytize antigens and present them to T cells for immune activation.
- Tactile Cells: Located at the epidermal-dermal junction; associated with sensory nerve endings.

Layers of the Epidermis

Five layers, from deep to superficial:
- Stratum Basale: Deepest layer with cuboidal keratinocytes; cells undergo mitosis about every 20 days.
- Stratum Spinosum: Contains several layers of keratinocytes unified by desmosomes; limited cell division occurs.
- Stratum Granulosum: Comprises 2-5 layers; cells begin keratinization as organelles die and accumulate keratohyaline granules.
- Stratum Lucidum: A clear layer found where skin is thickest; contains keratin; difficult to view under a microscope.
- Stratum Corneum: Outermost layer with 25 layers of dead keratinized cells; provides ultimate protection and flexibility.

Dermis

Forms the bulk of the skin; tough and leathery; composed mainly of fibrous connective tissue, allowing mobility for cells like phagocytes.

Dermal Layers

Two primary layers:
- Papillary Layer: Superficial layer that supplies blood and removes waste; extends toward the epidermis.
- Reticular Layer: Deeper layer with organized, dense fibrous connective tissue, important for cleavage lines used in surgery.

Skin Color Factors

Determined by three pigments:
- Melanin: Produced by melanocytes; levels vary by genetics, hormones, and sun exposure.
- Carotene: Contributes to skin color, especially in areas like palms and soles.
- Hemoglobin: Affects skin color based on oxygenation levels in the blood.

Skin Color Genetics

Variability in skin color reflects melanin production; individuals with darker skin have melanocytes that produce more and denser melanin.

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Description

Explore the key concepts of the integumentary system with this informative quiz. From understanding the layers of skin to the functions of hair and nails, test your knowledge and deepen your comprehension of this essential body system.