Integumentary System Chapter 5 Quiz

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Questions and Answers

What type of secretion do sebaceous glands primarily release?

Apocrine secretion

Endocrine secretion

Holocrine secretion (correct)

Merocrine secretion

Which gland in the integumentary system is responsible for producing cerumen?

Sebaceous glands

Mammary glands

Apocrine glands

Ceruminous glands (correct)

Which component of skin provides a chemical barrier against bacterial growth?

Sebum (correct)

Collagen

Keratin

Glycolipids

What is the primary function of apocrine sweat glands?

Secretion of fatty substances and proteins Signup and view all the answers

Which of the following is NOT a function of the integumentary system?

Movement Signup and view all the answers

At what life stage do apocrine sweat glands begin to function?

At puberty Signup and view all the answers

What is the only pigment produced by the skin?

Melanin Signup and view all the answers

Which factor does NOT influence the differences in skin color?

Presence of hair follicles Signup and view all the answers

What characteristic allows the skin to act as a barrier to water-soluble substances?

Flat, dead cells of the stratum corneum Signup and view all the answers

What process is enhanced during UV exposure that increases melanin production?

Tyrosinase activity Signup and view all the answers

Which of the following protects against UV radiation damage?

Melanin Signup and view all the answers

What occurs to melanin granules to shield DNA from UV radiation?

They accumulate on the apical side of the nucleus Signup and view all the answers

What is the primary function of mammary glands?

Secreting milk Signup and view all the answers

What happens during the tanning process?

Darkening of existing melanin and increased release Signup and view all the answers

Which type of sweat is produced by apocrine sweat glands?

Viscous sweat with proteins Signup and view all the answers

Albinism is characterized by which condition?

Complete absence of melanin synthesis Signup and view all the answers

What structure contains concentric layers of supporting cells around a sensory nerve ending?

Pacinian corpuscle Signup and view all the answers

Which layer of the skin is primarily responsible for the yellow to orange pigment accumulation?

Stratum corneum Signup and view all the answers

Which of the following epidermal derivatives does NOT include hair?

Adipose tissue Signup and view all the answers

Which of the following is NOT true regarding melanocytes?

Their number per area is influenced by race Signup and view all the answers

What is a function of dendritic cells in the epidermis?

To present foreign antigens to white blood cells Signup and view all the answers

Which of the following correctly describes the response to elevated body temperature?

Dilation of dermal blood vessels Signup and view all the answers

What occurs in the skin during exposure to a cold external environment?

Constriction of dermal blood vessels Signup and view all the answers

What is one of the metabolic functions of the skin?

Synthesis of Vitamin D precursor Signup and view all the answers

Which type of receptor is responsible for detecting touch and pressure sensations in the skin?

Exteroceptors Signup and view all the answers

What role do dermal macrophages play in the immune response?

Present foreign antigens to white blood cells Signup and view all the answers

How much fluid is lost per day through insensible perspiration?

500 ml Signup and view all the answers

What is a characteristic of sensible perspiration?

It involves significant heat loss Signup and view all the answers

What is a significant feature of the cutaneous sensory receptors?

They detect temperature and pain sensations Signup and view all the answers

Which statement about the blood reservoir function of the skin is correct?

The skin can hold about 5% of the body’s blood volume Signup and view all the answers

What is the primary function of keratin in the skin?

To form the outer protective layer of skin Signup and view all the answers

Where are melanocytes primarily located within the epidermis?

In the stratum basale Signup and view all the answers

How long does it take for a cell to migrate from the stratum basale to the surface of the skin?

25-45 days Signup and view all the answers

What type of connective tissue predominantly composes the dermis?

Dense irregular connective tissue Signup and view all the answers

What characteristic distinguishes thick skin from thin skin?

Thickness of the epidermal layer Signup and view all the answers

What is the primary function of the stratum corneum?

Water loss prevention Signup and view all the answers

Which layer of the dermis is associated with pain receptors?

Papillary dermis Signup and view all the answers

What type of cells in the epidermis are primarily responsible for cell-mediated immunity?

Dendritic (Langerhans) cells Signup and view all the answers

What do the dermal papillae contain that is critical for skin sensitivity?

Capillary loops and Meissner's corpuscles Signup and view all the answers

What layer of the epidermis is characterized as the 'prickly layer'?

Stratum spinosum Signup and view all the answers

What is the main role of the hypodermis?

Anchor skin to muscles and absorb shock Signup and view all the answers

What is primarily responsible for the waterproof properties of the epidermis?

Glycolipids Signup and view all the answers

Which layer of skin is NOT considered a part of the skin itself?

Hypodermis Signup and view all the answers

What is the function of the fibroblasts found in the dermis?

Secrete collagen and elastin fibers Signup and view all the answers

What is one of the primary functions of hair on the head?

Protects against physical trauma, heat loss, and sunlight Signup and view all the answers

What is the function of nose hairs?

Filter particles from the air Signup and view all the answers

What type of keratin is found in hair, making it tougher and more durable?

Hard keratin Signup and view all the answers

Where does hair growth primarily occur?

In the hair matrix Signup and view all the answers

What type of cells primarily make up the medulla of hair?

Large cells and air spaces Signup and view all the answers

What role do hair follicles play in hair structure?

House the hair bulb and root Signup and view all the answers

What is the arrector pili muscle responsible for?

Causing 'goose bumps' Signup and view all the answers

Which layer of hair contains several flattened cells?

Cortex Signup and view all the answers

What type of sweat gland is most numerous and located on palms and soles?

Eccrine (merocrine) sweat gland Signup and view all the answers

What structure provides blood supply to the hair follicle?

Hair papilla Signup and view all the answers

What layer of hair is the outermost and consists of single overlapping cells?

Cuticle Signup and view all the answers

What is a characteristic of eccrine sweat glands?

Have a simple coiled tubular structure Signup and view all the answers

Which component of hair is absent in fine hairs?

Medulla Signup and view all the answers

What is the primary role of hair receptors found in the hair bulb?

Detect movements or touch Signup and view all the answers

Study Notes

Skin Overview

Skin is the largest organ of the body.
Composed of two main regions: epidermis and dermis.

Epidermis

Made up of epithelial tissue; avascular (lacks blood vessels).

Dermis

Located beneath the epidermis; primarily fibrous connective tissue; vascularized (contains blood vessels).
Nutrients are diffused from the dermis to the epidermis.

Hypodermis (Superficial Fascia)

Not part of the skin; subcutaneous layer composed mostly of adipose tissue.
Functions: absorbs shock, stores fat, insulates, and anchors skin to underlying muscles.

Fascia

A fibrous membrane that covers, supports, and separates muscles.

Cells of the Epidermis

Keratinocytes: The majority of epidermal cells; produce keratin.
Melanocytes: Located in deeper epidermal layers; synthesize melanin to provide UV protection.
Dendritic (Langerhans) Cells: Function as macrophages in the skin.
Tactile (Merkel) Cells: Serve as sensory touch receptors.

Layers of the Epidermis

Thick Skin: Found in areas subjected to abrasion (e.g., palms, fingertips); contains five strata.
Thin Skin: Contains four layers.

Stratum Basale (Basal Layer)

Deepest layer; single layer of actively mitotic cuboidal stem cells.
Melanocytes comprise about 10-25% of this layer; produce melanin for UV protection.

Stratum Spinosum (Prickly Layer)

Several cell layers thick; contains pre-keratin bundles.
Characterized by dendritic cells and abundant melanin granules.

Stratum Granulosum (Granular Layer)

Thin layer (1-5 cell layers); cells begin to flatten and disintegrate.
Accumulation of keratohyaline and lamellar granules, which contain water-resistant glycolipids.

Stratum Lucidum (Clear Layer)

Present only in thick skin; superficial to the stratum granulosum.
Composed of 2-3 rows of flat, dead keratinocytes.

Stratum Corneum

Thickest layer (20-30 rows of dead, flat, keratinized cells).
Provides protective barrier against abrasion, penetration, and water loss through keratin and glycolipids.

Cell Differentiation in Epidermis

Transition from stratum basale to stratum corneum; cells shed about 50,000 per minute as dander and dandruff.

Dermis

Comprised of connective tissue that supports and binds epidermis to hypodermis.
Houses blood vessels, nerves, glands, and hair follicles.

Papillary Dermis

The upper layer of the dermis; contains areolar connective tissue.
Features dermal papillae with capillary loops and Meissner's corpuscles for light touch sensitivity.

Reticular Dermis

Constitutes about 80% of dermal thickness; made of dense irregular connective tissue.
Contains collagen fibers for strength and elastic fibers for stretchability.
Includes cleavage lines (tension lines) and flexure lines near joints.

Skin Color

Determined by pigments: melanin (only skin-produced pigment), carotene (yellow-orange), and hemoglobin (red in blood).

Melanin Synthesis

Tyrosinase enzyme converts tyrosine to melanin; melanin protects against UV damage.
Number of melanocytes does not vary by gender or race; differences arise from pigment type and distribution.

Tanning and Albinism

Tanning results from UV exposure stimulating melanin production.
Albinism: Melanin production is severely reduced or absent.

Epidermal Derivatives

Includes hair and hair follicles, nails, sweat glands, and sebaceous (oil) glands.

Hair (Pili)

Composed of dead keratinized cells; absent from specific areas like palms and soles.
Serves various functions including protection and thermoregulation.### Functions of Hair
Warns of insects crawling on the skin, serving as a sensory function.
Hair on the head acts as a barrier against physical trauma, reduces heat loss, and protects from sunlight.
Eyelashes protect the eyes from debris and small particles.
Nose hairs filter and trap particles, preventing entry into the respiratory system.

Characteristics of Hair

Hard keratin in hair makes it tougher and more resilient compared to soft keratin in the skin.
Hair cells do not flake off like skin cells.
The hair root is embedded within the skin, while the shaft is visible above the surface.

Structure of Hair

Medulla: Central core composed of large cells and air spaces, containing soft keratin; absent in fine hairs.
Cortex: Major component of hair, consists of several layers of flattened cells.
Cuticle: Outermost layer, made of a single layer of overlapping cells.

Hair Follicle Anatomy

Extends from the epidermis surface to the dermis, consisting of a two-layered wall formed by dermis and epidermis.
Hair Bulb: Deep, expanded part containing sensory nerve endings (root hair plexus).
Hair Papilla: Dermal tissue supplying blood to the hair.

Hair Follicle Components

Peripheral Connective Tissue Sheath: Derived from the dermis.
Glassy Membrane: Serves as the basement membrane for the epithelial root sheath.
Epithelial Root Sheath: Contains external root sheath (continuation of epidermis) and internal root sheath (derived from matrix cells).
Hair Matrix: Location of dividing cells adjacent to the hair papilla.
Arrector Pili Muscle: Smooth muscle causing "goose bumps" by contracting.

Nails

Nails are scale-like modifications of the epidermis providing protection over the distal phalanges.
Composed of hard keratin with growth occurring at the nail matrix.

Sweat Glands

Two types: Eccrine (merocrine) and Apocrine glands.
Eccrine Sweat Glands: Most numerous, found on the soles, palms, and forehead; contribute to thermoregulation through merocrine secretion.
Apocrine Sweat Glands: Located in axillary and anogenital regions, secrete viscous sweat that contains fatty substances and proteins, activated at puberty.

Modified Apocrine Sweat Glands

Ceruminous Glands: Found in the external ear canal, secrete cerumen (earwax) to deter insects and block foreign material.
Mammary Glands: Specialized to secrete milk.

Sebaceous Glands

Absent in thick skin (palms, soles); associated with hair follicles.
Simple branched alveolar glands secreting sebum via holocrine secretion that acts as a protective film, preventing drying and keeping the skin soft.

Functions of the Integumentary System

Protection: Skin serves as the body's primary defense against environmental hazards.
Body Temperature Regulation: Thermoregulation through sweat and blood vessel dilation/constriction.
Cutaneous Sensation: Receptors enable touch, pressure, temperature, and pain sensing.
Metabolic Functions: Involves synthesis of vitamin D precursor and collagenase.
Blood Reservoir: Holds up to 5% of the body's blood volume.
Excretion: Eliminates nitrogenous wastes and salts through sweat.

Protection Mechanisms

Chemical Barriers: Skin secretions maintain a low pH, inhibiting bacterial growth; melanin provides UV protection.
Physical Barriers: Stratum corneum's dead, flat cells and lipids block most substances.
Biological Barriers: Dendritic cells and dermal macrophages present foreign antigens to the immune system.

Temperature Regulation

Normal perspiration around 500 ml/day; increased sweating and blood vessel dilation cools the body during heat.
Constriction of dermal blood vessels retains heat in cold environments.

Sensation and Responses

Exteroceptors enable cutaneous sensory perception; motor information leads to reflex actions like sweating and goosebumps.

Other Functions

Metabolically synthesizes essential compounds and facilitates hormone activation.
Acts as a waste excretion system, expelling materials through sweat.

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Description

Test your knowledge on the Integumentary System, focusing specifically on the structure and function of the skin. This quiz covers the epidermis and dermis, highlighting their composition and distinct characteristics. Perfect for students studying anatomy and physiology.