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Questions and Answers
What is the primary function of melanocytes?
What is the primary function of melanocytes?
The epidermis is avascular, meaning it does not contain any blood vessels.
The epidermis is avascular, meaning it does not contain any blood vessels.
True
Name the largest organ of the human body.
Name the largest organ of the human body.
skin
The ________ layer anchors skin structures to the fascia and contains pressure receptors.
The ________ layer anchors skin structures to the fascia and contains pressure receptors.
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Match the following cell types to their functions in the epidermis:
Match the following cell types to their functions in the epidermis:
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What is the primary function of hair in the integumentary system?
What is the primary function of hair in the integumentary system?
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Basal cell carcinomas are the most common type of skin cancer.
Basal cell carcinomas are the most common type of skin cancer.
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What are the three layers that make up a hair shaft?
What are the three layers that make up a hair shaft?
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Hair protects the scalp from UV radiation and the eyes and nasal cavity from __________.
Hair protects the scalp from UV radiation and the eyes and nasal cavity from __________.
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Which type of skin cancer represents 20% of skin cancers?
Which type of skin cancer represents 20% of skin cancers?
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The hair follicle is composed only of connective tissue.
The hair follicle is composed only of connective tissue.
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What is the role of the arrector pili muscle?
What is the role of the arrector pili muscle?
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Match the type of skin cancer with its associated layer of the skin:
Match the type of skin cancer with its associated layer of the skin:
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What type of cells are involved in sensing touch?
What type of cells are involved in sensing touch?
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The epidermis is composed of three strata.
The epidermis is composed of three strata.
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What is the deepest layer of the epidermis called?
What is the deepest layer of the epidermis called?
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The stratum granulosum seals the epidermis and contains dying cells undergoing __________.
The stratum granulosum seals the epidermis and contains dying cells undergoing __________.
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Match the layers of the epidermis with their characteristics:
Match the layers of the epidermis with their characteristics:
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Which of the following describes the papillary region of the dermis?
Which of the following describes the papillary region of the dermis?
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The stratum corneum is made up of living cells.
The stratum corneum is made up of living cells.
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How long does it take for new cells at the stratum basale to reach the stratum corneum?
How long does it take for new cells at the stratum basale to reach the stratum corneum?
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The ___________ region of the dermis helps to anchor it to the subcutaneous layer.
The ___________ region of the dermis helps to anchor it to the subcutaneous layer.
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What is the primary reason for differences in human skin color?
What is the primary reason for differences in human skin color?
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Fingerprints are unique to each individual due to their epidermal ridges.
Fingerprints are unique to each individual due to their epidermal ridges.
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What enzyme is responsible for melanin synthesis?
What enzyme is responsible for melanin synthesis?
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Match the skin conditions with their descriptions:
Match the skin conditions with their descriptions:
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Tattoos require ink to be deposited into the __________ of the skin for permanence.
Tattoos require ink to be deposited into the __________ of the skin for permanence.
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Study Notes
Integumentary System Overview
- Comprises skin, hair, nails, oil glands, sweat glands, and sensory receptors.
- Skin is the largest organ, representing about 7% of body weight.
- Thickness varies: 0.5 mm on eyelids; up to 4 mm on heels.
Skin Structure
- Epidermis: Surface layer, avascular (lacks blood vessels).
- Dermis: Deep layer made of connective tissue, vascularized.
- Subcutaneous Layer (Hypodermis): Anchors skin structures to underlying fascia; contains pressure receptors.
Functions of the Integumentary System
- Regulates body temperature.
- Provides protection from external harm.
- Sensory signal detection.
- Facilitates chemical excretion and absorption.
- Stores blood and energy.
- Synthesizes vitamin D.
Epidermis Composition
- Made of keratinized stratified squamous epithelium.
- Primary cell types include:
- Keratinocytes: Produce keratin and waterproofing lamellar granules.
- Melanocytes: Produce melanin, providing UV protection.
- Langerhans cells: Immune cells (UV-sensitive macrophages) that perform phagocytosis.
- Tactile epithelial cells: Responsible for touch sensation.
Epidermal Stratification
- Typically four strata in most skin; five strata in high-abrasion areas (palms, soles).
- Strata include:
- Stratum basale: Deepest layer; contains stem cells; high in keratin filaments.
- Stratum spinosum: Provides strength; 8-10 layers of keratinocytes with desmosomes.
- Stratum granulosum: Contains dying cells that produce keratin and lipids for waterproofing.
- Stratum corneum: Outermost layer; composed of dead, flattened keratinized cells.
- Stratum lucidum: Present only in thick skin; consists of clear, dead keratinocytes for added support.
Dermis Structure
- Composed of dense connective tissue with two main regions:
- Papillary Region: Areolar connective tissue; contains dermal papillae with capillaries and sensory neurons (20% of dermis).
- Reticular Region: Dense irregular connective tissue; contains collagen fibers, resists stretching and shear (80% of dermis).
Fingerprints
- Formed by interlocking epidermal ridges, unique to each individual.
- Increases friction for grip and enhances touch sensitivity.
Skin Color Variation
- Differences in skin color arise from varying amounts of melanin produced by melanocytes.
- Everyone has a similar number of melanocytes; factors influencing melanin levels include UV exposure.
- A tan occurs due to increased tyrosinase activity in melanocytes, enhancing melanin synthesis.
Hair Structure and Function
- Hair provides insulation and protects against UV radiation; contains touch receptors.
- Composed of:
- Hair Root: Embedded in dermis/subcutaneous layer.
- Hair Shaft: Visible part; consists of medulla, cortex, and cuticle.
- Hair follicles contain epithelial tissue and a hair matrix for growth.
Skin Cancer Types
- Basal Cell Carcinoma: Originates from stratum basale; most common skin cancer (78%).
- Squamous Cell Carcinoma: Arises from stratum spinosum; accounts for 20% of skin cancers.
- Malignant Melanoma: Cancer of melanocytes; can be aggressive.
Summary of Integumentary Functions
- Protects from abrasion, dehydration, UV irradiation, and invasion by pathogens.
- Skin colors result from differential melanin secretion.
- Wound healing is crucial for homeostasis.
- Burns can lead to serious complications like edema and sepsis.
- Excessive UV exposure may lead to skin cancer and uncontrolled cell proliferation.
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Description
Explore the structure and functions of the integumentary system, including skin, hair, and nails. This quiz covers the layers of skin and their roles in protection, sensation, and temperature regulation. Test your knowledge about the components and significance of this essential system.
