Questions and Answers
What is the primary function of keratinocytes in the epidermis?
Which layer of the epidermis contains dead, flattened cells filled with keratin?
Which cell type in the epidermis is primarily responsible for UV protection?
What characterizes the dermis compared to the epidermis?
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Which of the following accurately describes the stratum lucidum?
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What is the primary role of Langerhan's cells in the integumentary system?
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What type of tissue primarily composes the hypodermis?
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Which layer of the epidermis is characterized by limited mitotic activity?
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What is the general effect of the integumentary system on an individual's self-image?
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How many layers make up the stratum corneum?
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Which component of hair is responsible for its protective function and sensation?
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What determines the color of hair, particularly black and blond shades?
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What is the function of sebaceous glands in the skin?
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Which type of sweat gland is most densely concentrated in the palms and soles?
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What structure in the hair follicle contracts in response to cold or emotional crisis?
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Which layer of the nail is commonly referred to as the cuticle?
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How does a lack of pigmentation in hair primarily manifest?
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What type of secretion do sebaceous follicles produce directly onto the skin?
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Which type of gland is primarily responsible for evaporative cooling of the body?
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What is the primary function of nails?
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Which type of secretion is produced by apocrine glands?
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What is the primary function of ceruminous glands?
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What characterizes a third-degree burn?
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What occurs during the pathophysiology of burns, leading to dizziness or syncope?
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Which type of connective tissue is characterized by closely packed collagen fibers in a parallel arrangement?
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What type of junctions are intercalated disks primarily composed of?
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Which of the following statements is incorrect regarding mammary glands?
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What is the typical characteristic of apocrine secretions?
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When observing a tissue with blisters and swelling, what degree of burn is likely present?
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What is the primary role of sweat in the human body?
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What is the primary role of melanin in the skin?
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Which condition is characterized by a lack of tyrosinase?
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Which pigment accumulates in the stratum corneum and gives a yellowish hue?
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What is cyanosis associated with?
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Which of the following functions of the skin involves preventing water absorption?
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What does hyperkeratosis involve?
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Which of the following statements about vitamin D synthesis is correct?
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Which sensation is NOT detected by the sensory receptors in the dermis?
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What process allows for transdermal drug delivery?
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What does the stratum basale primarily protect against?
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Study Notes
Integumentary System Overview
- Largest organ system, critical for overall health and self-image.
- Comprises epithelial, muscle, nervous, and connective tissues.
- Can indicate disease presence and host various disorders.
Tissue Layers of Skin
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Epidermis: Outermost layer, primarily made of keratinocytes (90%).
- Keratinocytes produce keratin and are mitotically active in the deepest layers.
- Melanocytes (8%) synthesize melanin to protect against UV radiation.
- Contains Langerhans cells (immune function) and Merkel’s cells (sensory receptors).
- Organized into five strata:
- Stratum Basale: Deepest, cuboidal cells, mitotically active.
- Stratum Spinosum: Spiny appearance, limited mitosis.
- Stratum Granulosum: Granulated cells producing keratin and keratohyalin.
- Stratum Lucidum: Present in palms/soles, filled with keratin.
- Stratum Corneum: 25-30 layers of dead keratinized cells.
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Dermis: Thicker than epidermis, composed of elastic and collagen fibers.
- Rich vascularization, contains glands (sweat, sebaceous), hair follicles, nerves, and sensory receptors.
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Hypodermis: Made up of loose connective and adipose tissues for structural attachment.
Skin Color
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Melanin: Black pigment, its amount dictates skin color variations.
- Protects basal layer from UV rays; synthesis increases with UV exposure.
- Skin conditions include freckles, albinism (tyrosinase deficiency), vitiligo (melanocyte loss), and hyperkeratosis (benign growth).
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Carotene: Yellow pigment from plants, accumulates in stratum corneum.
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Hemoglobin: Oxygen-carrying pigment in blood; cyanosis indicates hypoxia (bluish skin).
Functions of the Skin
- Physical Protection: Barrier to microbes, water, and radiation; thickens due to friction (callus formation).
- Hydroregulation: Virtually waterproof, prevents dehydration.
- Thermoregulation: Manages body temperature through sweating and vasoconstriction.
- Synthesis: Produces melanin and keratin; UV exposure activates Vitamin D.
- Absorption: Allows uptake of certain substances (e.g., medications via transdermal patches).
- Sensory Reception: Contains receptors for temperature, pressure, pain, etc.
- Communication: Facial expressions and skin color changes reflect emotions.
Epidermal Derivatives
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Hair:
- Functions: Protection, sensation, filtering, and sexual attraction.
- Anatomy includes shaft, root, follicle, and arrector pili muscles.
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Nails:
- Protect fingertip ends and assist in manipulation.
- Composed of various parts: nail body, lunula, root, cuticle, and hyponychium.
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Glands:
- Sebaceous Glands: Oil production, associated with hair follicles; secrete sebum containing lipids and antibiotics.
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Sudiferous (Sweat) Glands:
- Merocrine: Common in palms and soles, involved in thermal regulation and excretion.
- Apocrine: Found in axillary and pubic regions, secretes pheromones, activated at puberty.
- Mammary Glands: Specialized glands for milk production; discussed within the reproductive system.
- Ceruminous Glands: Secretes earwax (cerumen) as an insect and water repellent.
Clinical Considerations
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Burn Classification:
- First Degree: Affects only the epidermis, causes redness and pain.
- Second Degree: Involves epidermis and dermis, results in blisters.
- Third Degree: Damages entire skin and underlying tissues; may lead to scarring.
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Common Symptoms: Redness from vasodilation, swelling from capillary filtration, potential dizziness or shock due to dehydration, and risk of systemic infection.
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Description
Test your knowledge on the integumentary system with this quiz based on Lecture #4. Covering MTT, chapter 4, you'll explore the composition, functions, and significance of this largest organ system, alongside relevant clinical implications. Answer i-clicker questions to reinforce your understanding.
