L10

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Questions and Answers

What is the primary role of the epidermis in the integumentary system?

To provide sensation through nerve endings

To act as a waterproof barrier with keratinization (correct)

To support and nourish the dermis

To produce sweat and regulate temperature

Which of the following statements about thick and thin skin is accurate?

Thin skin typically lacks hair follicles.

Thin skin is characterized by a higher density of keratinocytes.

Thick skin is predominantly found on the palms and soles. (correct)

Thick skin contains more sebaceous glands than thin skin.

Which function of the skin involves producing a vitamin that is crucial for calcium absorption?

Sensation of touch

Vitamin D synthesis (correct)

Protection against pathogens

Temperature regulation

Which of the following appendages is NOT a component of the integumentary system?

Adipose tissue Signup and view all the answers

What percentage of body weight is primarily attributed to the skin? (review)

16% Signup and view all the answers

What type of glands secrete sweat without loss of other cellular materials?

Merocrine glands Signup and view all the answers

Which sweat glands are primarily involved in emotional sweating?

Eccrine glands Signup and view all the answers

Where are apocrine sweat glands predominantly located?

Armpits and groin Signup and view all the answers

What is the main function of ceruminous glands?

Produce ear wax Signup and view all the answers

Which type of gland releases its secretion along with parts of the cell's cytoplasm?

Apocrine gland Signup and view all the answers

What cellular structure provides the blood supply to the hair follicle?

Dermal papilla Signup and view all the answers

What characteristic is true of the cells that make up hair?

They are keratinized and dead Signup and view all the answers

What type of secretion is associated with sebaceous glands?

Holocrine secretion Signup and view all the answers

Which layer of the epidermis is responsible for cell regeneration?

Stratum basale Signup and view all the answers

What is the main type of cell found in the thick skin of the epidermis?

Keratinocytes Signup and view all the answers

Which type of gland is primarily associated with producing an oily substance to protect hair?

Sebaceous glands Signup and view all the answers

Which of these structures is NOT typically found in thick skin?

Hair follicles Signup and view all the answers

Meissner's corpuscles in the skin are primarily responsible for sensing what type of stimuli?

Light touch Signup and view all the answers

In comparison to thin skin, what characteristic of thick skin is most notable?

Thicker stratum corneum Signup and view all the answers

The dermis is divided into which two layers?

Papillary and reticular layers Signup and view all the answers

Which type of epidermal cell is primarily involved in immune response?

Langerhans cells Signup and view all the answers

Which receptor is responsible for detecting sustained pressure?

Ruffini's end organ Signup and view all the answers

Which feature is characteristic of the superficial papillary layer of the dermis?

Rich in blood capillaries Signup and view all the answers

Which of the following accurately describes the function of skin as part of the integumentary system?

Serves as a barrier to protect underlying tissues Signup and view all the answers

What is the primary structural characteristic that differentiates thick skin from thin skin?

Thickness of the epidermis Signup and view all the answers

In what way do sweat glands play a role in controlling body temperature?

Through the evaporation of sweat from the skin surface Signup and view all the answers

Which layer of skin is chiefly responsible for housing the majority of skin appendages such as glands and hair follicles?

Dermis Signup and view all the answers

Which type of receptor in the skin is primarily involved in detecting fine touch?

Meissner's corpuscles Signup and view all the answers

Which type of sweat gland primarily helps in thermoregulation?

Eccrine sweat glands Signup and view all the answers

What type of gland is responsible for the production of ear wax?

Ceruminous glands Signup and view all the answers

Which statement correctly describes the structure of hair?

Hair is made up of columns of dead keratinized cells. Signup and view all the answers

Which gland is classified as a holocrine gland?

Sebaceous glands Signup and view all the answers

Where do apocrine sweat glands primarily discharge their secretions?

Into hair follicles Signup and view all the answers

What role do myoepithelial cells play in sweat glands?

They contract to expel sweat from glands. Signup and view all the answers

What is the primary function of the arrector pili muscle?

To raise hair follicles during cold or fear Signup and view all the answers

Which of the following correctly describes the secretion method of merocrine glands?

They release secretory granules via exocytosis without cell loss. Signup and view all the answers

Which cell type is most abundant in the thick skin of the epidermis?

Keratinocytes Signup and view all the answers

What differentiates the stratum corneum in thick skin from that in thin skin?

It is significantly thicker in thick skin. Signup and view all the answers

Which layer of the dermis is primarily responsible for tactile sensation?

Papillary layer Signup and view all the answers

What is the primary function of the sebaceous glands?

To secrete an antibacterial substance. Signup and view all the answers

Which feature is characteristic of thin skin compared to thick skin?

Thinner stratum corneum. Signup and view all the answers

Which mechanoreceptor is primarily responsible for detecting deep pressure?

Pacinian corpuscle Signup and view all the answers

What is a notable difference between the papillary and reticular layers of the dermis?

Reticular layer has a denser connective tissue composition. Signup and view all the answers

Which type of epidermal cell is involved in the synthesis of melanin?

Melanocytes Signup and view all the answers

What is a characteristic feature of the dermal papillae?

They increase the surface area for exchange. Signup and view all the answers

Which of the following receptors is NOT classified as a mechanoreceptor?

Thermoreceptor Signup and view all the answers

Study Notes

Integumentary System - Skin and its Appendages

The integumentary system encompasses the skin and its appendages, including hair, sebaceous glands, nails, and sweat glands.
Functions of skin include: covering and protecting the body, regulating internal temperature, producing vitamin D, detecting environmental stimuli, and regulating substances moving into and out of the body.
Skin represents the largest organ, making up 16% of body weight.

Layers of Skin

Epidermis: outermost layer, composed of stratified squamous keratinized epithelium.
- Keratin production creates a waterproof barrier.
- Contains pigments (melanin) for UV protection.
Dermis: living layer below epidermis, mainly dense connective tissue.
- Contains fibers, cells, blood vessels, glands (sweat & sebaceous), and hairs.
Hypodermis: layer beneath dermis, composed of adipose tissue and receptors.

Epidermis and Dermis Details

Epidermis:
- Contains specialized layers like stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (sometimes absent), and stratum corneum.
- Different skin types (thick/thin) exist. Thick skin is found on palms and soles. It has a complete stratum lucidum and is thicker. Thin skin covers other body parts, lacking stratum lucidum, being thinner.
Dermis:
- Two layers - superficial papillary layer (loose connective tissue, blood vessels, nerves, and lymphatics, containing Meissner's corpuscles), and deeper reticular layer (dense fibrous connective tissue, containing Krause end bulbs, Pacinian corpuscles, and Ruffini corpuscles).

Layers of Epidermis

Stratum basale (germinativum)
Stratum spinosum
Stratum granulosum
Stratum lucidum (if present)
Stratum corneum

Types of Epidermal Cells

Keratinocytes (85% of cells)
Melanocytes
Langerhans cells
Merkel cells

Thick Skin

Thickness : 0.8mm in palm to 1.4mm in sole
Contains four cell types: keratinocytes (majority), melanocytes, Langerhans cells, and Merkel cells.
Arranged in five layers.

Thin Skin

Thinner than thick skin, lacking stratum lucidum.
Contains fewer sweat glands.
Has hair follicles, arrector pili muscles, and sebaceous glands.
Most of the body is covered by thin skin except the palms and soles.

Differences Between Thin and Thick Skin

Stratum spinosum and corneum are thicker in thick skin, and stratum lucidum is present.
Epidermal ridges are present in thick skin but absent in thin skin.
Hair follicles, arrector pili muscles, and sebaceous glands are present in thin skin but absent in thick skin.
Sweat glands are more numerous in thick skin.
Sensory receptors tend to be more concentrated in the thick skin.

The Dermis

Papillary layer: forms dermal papillae, containing loose connective tissue, rich in collagen type III, elastic fibers, connective tissue cells, and blood capillaries. Contains Meissner's corpuscles.
Reticular layer: thicker deep layer, dense connective tissue, contains a high proportion of nerve receptors (e.g., Krause end bulbs, Pacinian corpuscles, Ruffini corpuscles, and many nerve endings), and is less vascular.

Receptors of Skin

Sensory receptors of skin include cutaneous mechanoreceptors (like Ruffini corpuscles, Meissner's corpuscles, Pacinian corpuscles, Merkel's discs(for sustained touch & pressure), free nerve endings), thermoreceptors, nociceptors, bulbous corpuscles, and chemoreceptors.

Glands and Appendages of Skin

Sebaceous glands: clumps of epithelial tissue, secreting sebum (oily substance), located all over the body, usually associated with hair follicles.
Sweat glands: microscopic clumps of epithelial tissue in dermis, leading outside through pores; producing sweat.
Eccrine sweat glands: concentrated on hands, feet & forehead; helping cool down the body.
Apocrine sweat glands: concentrated in armpits & groin; producing specific odor, associated with hair follicles.
Ceruminous glands: modified sweat glands in ear canal, producing ear wax.
Mammary glands: modified sweat glands in female breasts, producing milk.

Classification of Glands by Secretion

Merocrine: secretory granules leave the cell by exocytosis. Example, pancreatic glands and eccrine sweat glands.
Apocrine: secretory granules discharge along with portions of the apical cytoplasm. Example, some sweat glands.
Holocrine: secretory granules shed with the entire cell. Example, sebaceous glands.

Hair

Hair follicles are tubular invaginations of the epidermis, composed of dead keratinized cells.
Parts of hair include the medulla, cortex, cuticle, and the hair bulb. The base of the hair follicle, the hair bulb, contains the dermal papilla with blood supply for the hair.
Arrector pili muscles associated with hair follicles contract to elevate the hair, contributing to goosebumps.
Sebaceous glands discharge sebum onto the hair shaft.

Nails

Nails are hard keratin plates covering the dorsal tips of fingers and toes.
Key parts of nails include nail body, nail root, nail matrix, eponychium (cuticle), nail bed, free edge, and lunula

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Description

Explore the integumentary system, focusing on the skin and its appendages. Understand the structure of the skin, its layers including the epidermis and dermis, and key functions such as protection and temperature regulation. This quiz covers essential facts and details about skin anatomy and physiology.

L10

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