Chapter 5 Flashcards
Acne
Skin condition due to infected sebaceous glands
Albinism
Genetic disorder that affects the skin, in which there is no melanin production
Anagen
Active phase of the hair growth cycle
Apocrine sweat gland
Type of sweat gland that is associated with hair follicles in the armpits and genital regions
Arrector pili
Smooth muscle that is activated in response to external stimuli that pull on hair follicles and make the hair “stand up”
Basal cell
Type of stem cell found in the stratum basale and in the hair matrix that continually undergoes cell division, producing the kertinocytes of the epidermis
Basal Cell Carcinoma
Cancer that originates from basal cells in the epidermis of the skin
Bedsore
Sore on the skin that develops when regions of the body start necrotizing due to constant pressure and lack of blood supply; also called decubitis ulcers
Callus
Thickened area of skin that arises due to constant abrasion
Catagen
Transitional phase marking the end of the anagen phase of the hair growth cycle
Corn
Type of callus that is named for its shape and the elliptical motion of the abrasive force
Cortex
In hair, the second or middle layer of keratinocytes originating from the hair matrix, as seen in a cross-section of the hair bulb
Cuticle
In hair, the outermost layer of keratinocytes originating from the hair matrix, as seen in a cross-section of the hair bulb
Dermal papilla
(Plural = dermal papillae) extension of the papillary layer of the dermis that increases surface contact between the epidermis and dermis
Dermis
Layer of skin between the epidermis and hypodermis, composed mainly of connective tissue and containing blood vessels, hair follicles, sweat glands, and other structures
Desmosome
Structure that forms an impermeable junction between cells
Eccrine sweat gland
Type of sweat gland that is common throughout the skin surface; it produces a hypotonic sweat for thermoregulation
Eczema
Skin condition due to an allergic reaction, which resembles a rash
Elastin fibers
fibers made of the protein elastin, which resembles a rash
Eleiden
Clear protein-bound lipid found in the stratum lucidum that is derived from keratohyalin and helps to prevent water loss
Epidermis
Outermost tissue layer of the skin
Eponychium
Nail fold that meets the proximal end of the nail body, also called the cuticle
External root sheath
Outer layer of the hair follicle that is an extension of the epidermis, which encloses the hair root
First-degree burn
Superficial burn that injuries only the epidermis
Fourth-degree burn
Burn in which full thickness of the skin and underlying muscle and bone is damaged
Glassy membrane
Layer of connective tissue that surroundings the base of the hair follicle, connecting it to the dermis
Hair
Keratinous filament growing out of the epidermis
Hair bulb
Structure at the base of the hair root that surrounds the dermal papilla
Hair follicle
Cavity or sac from which hair originates
Hair matrix
Layer of basal cells from which a strand of hair grows
Hair papilla
Mass of connective tissue, blood capillaries, and nerve endings at the base of the hair follicle
Hair root
Part of hair that is below the epidermis anchored to the follicle
Hair shaft
Part of the hair that is above the epidermis but is not anchored to the follicle
Hypodermis
Connective tissue connecting the integument to the underlying bone and muscle
Hyponychium
Thickened layer of stratum corneum that lies below the free edge of the nail
Integumentary system
Skin and its accessory organs
Internal root sheath
Innermost layer of keratinocytes in the hair follicle that surround the hair root up to the hair shaft
Keloid
Type of scar that has layers raised above the skin surface
Keratin
Type of structural protein that gives skin, hair, and nails its hard, water-resistant properties
Keratinocytes
Cell that produces keratin and is the most predominant type of cell found in the epidermis
Keratohyalin
Granulated protein found in the stratum granulosum
Langerhans cell
Specialized dendritic cell found in the stratum spinosum that functions as a macrophage
Lunula
Basal part of the nail body that consists of a crescent-shaped layer of thick epithelium
Medulla
In hair, the innermost layer of keratinocytes originating from the hair matrix
Meissner corpuscle
(Also, tactile corpuscle) receptor in the skin that responds to light touch
Melanin
Pigment that determines the color of hair and skin
Melanocyte
Cell found in the stratum basale of the epidermis that produces the pigment melanin
Melanoma
Type of skin cancer that originates from the melanocytes of the skin
Melanosome
Intercellular vesicle that transfers melanin from melanocytes into keratinocytes of the epidermis
Merkel cell
Receptor cell in the stratum basale of the epidermis that responds to the sense of touch
Metastasis
Spread of cancer cells from a source to other parts of the body
Nail bed
Layer of epidermis upon which the nail body forms
Nail body
Main keratinous plate that forms the nail
Nail cuticle
Fold of epithelium that extends over the nail bed, also called the eponychium
Nail fold
Fold of epithelium that extends over the sides of the nail body, holding it in place
Nail root
Part of the nail that is lodged deep into the epidermis from which the nail grows
Pacinian corpuscle
(Also, lamellated corpuscle) receptor in the skin that responds to vibration
Papillary layer
Superficial layer of the dermis, made of loose, areolar connective tissue
Reticular layer
Deeper layer of the dermis; it has a reticulated appearance due to the presence of abundant collagen and elastin fibers
Rickets
Disease in children caused by vitamin D deficiency, which leads to the weakening of bones
Scar
Collagen-rich skin formed after the process of wound healing that is different from normal skin
Sebaceous gland
Type of oil gland found in the dermis all over the body and helps to lubricate and waterproof the skin and hair by secreting sebum
Sebum
Oily substance that is composed of a mixture of lipids that lubricates the skin and hair
Second-degree burn
Partial-thickness burn that injures the epidermis and a portion of the dermis
Squamous cell carcinoma
Type of skin cancer that originates from the stratum spinosum of the epidermis
Stratum basale
Deepest layer of the epidermis, made of epidermal stem cells
Stratum corneum
Most superficial layer of the epidermis
Stratum granulosum
layer of the epidermis superficial to the stratum spinosum
Stratum lucidum
Layer of the epidermis between the stratum granulosum and stratum corneum, found only in thick skin covering the palms, soles of the feet, and digits
Stratum Spinosum
Layer of the epidermis superficial to the stratum basale, characterized by the presence of desmosomes
Stretch mark
Mark formed on the skin due to a sudden growth spurt and expansion of the dermis beyond its elastic limits
Sudoriferous gland
Sweat gland
Telogen
Resting phase of the hair growth cycle initiated with catagen and terminated by the beginning of a new anagen phase of hair growth
Third-degree burn
Burn that penetrates and destroys the full thickness of the skin (epidermis and dermis)
Vitamin D
compound that aids absorption of calcium and phosphates in the intestine to improve bone health
Vitiligo
Skin condition in which melanocytes in certain areas lose the ability to produce melanin, possibly due to an autoimmune reaction that leads to loss of color in patches
What are the two major layers of the skin?
Superficial epidermis Deeper dermis
What are the layers of the epidermis from deep to superficial?
Stratum basale (germinatum) Stratum spinosum Stratum granulosum Stratum lucidum (in thick skin) Stratum corneum
What does the stratum corneum consist of?
Dead cells that shed periodically and is progressively replaced by cells formed from the basal layer
What does the stratum basale layer contain?
Melanocytes
What to melanocytes produce?
Melanin
What is melanin responsible for?
Giving skin its color. It is transferred to keratinocytes in the stratum spinosum to protect cells from UV rays.
What does the dermis do?
Connects the epidermis to the hypodermis. Provides strength and elasticity due to the presence of collagen and elastin fibers.
What are the layers of the dermis?
Papillary layer with papillae that extend into the epidermis and the lower, reticular layer composed of loose connective tissue
What is the hyodermis?
Layer that is deep to the dermis.
What is the hypdermis composed of?
Connective tissue that connects the dermis to underlying structures. Harbors adipose tissue for fat storage and protection.
What are some accessory structures of the skin?
Hair Nails Sweat glands Sebaceous glands
What is hair made of?
Dead keratinized cells
Where does hair get its color?
Melanin pigments
What are nails made of?
Dead keratinized cells
What is the function of nails?
Protect the extremities of our fingers and toes from mechanical damage
What do sweat glands produce?
Sweat
What do sebaceous glands produce?
Sebum
What is the purpose of sweat?
Cooling the body down when overheated. Helps excrete small amounts of metabolic waste.
What is the purpose of sebum?
Natural moisturizer - keeps the dead, flaky, outer keratin layer healthy
What are the roles the skin plays?
- Protection - first layer of defense to prevent dehydration, infection, and injury to the rest of the body .
- Sensing stimuli
- Thermoregulation - sweat glands and dilation or constriction of heat-carrying blood vessels in the skin.
- Vitamin D synthesis
What is the function of immune cells in the skin?
Patrol the areas to keep them free of foreign materials
What is the function of fat stores in the hypdermis?
Aids in thermogreulation and protection
Skin cancer is the result of?
Damage to the DNA of skin cells - often due to excessive exposure to UV radiation.
What two skin cancers are higly curable?
Basal cell carcinoma (from stratum basale) and squamous cell carcinoma (from stratum spinosum).
What is the most dangerous form of skin cancer?
Melanoma - affects melanocytes, which can spread/metastize to other organs
What are burns the result of?
Injury to the skin as a result of exposure to exteme heat, radiation, or chemicals
What types of burns heal quickly?
First- and second-degree burns
What types of burns can be fatal? Why?
Third-degree burns because they penetrate the full thickness of the skin
When do scars occur? How to they form?
Scars occur when there is repair of skin damage.
Fibroblasts generate scar tissue in the form of collagen, which forms a basket-weave pattern that looks different from normal skin.
What are besores from? Caracterized by?
From excessive pressure on the skin and underlying tissue.
Characterized by necrosis of tissue due to immobility.
What are stretch marks from? Characterized by?
Resupt of excessive pressure on the skin and underlying tissue
Result from rapid growth
What is eczema?
Allergic reaction that manifests as a rash.
Usually a long-term skin condition that may be successfully treated in mild cases.
What causes acne?
Clogged sebaceous glands. Usually a long-term skin condition that may be successfully treated in mild cases.
What causes corns and calluses?
Abrasive pressure on the skin.
The skin consists of two layers and a closely associated layer.
What are the basic functions of each layer?
- Epidermis
- Dermis
- Hypodermis
The papillary layer of the dermis is most closely associated with which layer of the epidermis?
a. Stratum spinosum
b. Stratum corneum
c. Stratum granulosum
d. Stratum basale
?????
Langerhans cells are commonly found in the ______.
a. Stratum spinosum
b. Stratum corneum
c. Stratum granulosum
d. Stratum basale
The papillary and reticular layers of the dermis are composed mainly of ____.
a. Melanocytes
b. Keratinocytes
c. Connective tissue
d. Adipose tissue
Collagen lends _____ to the skin.
a. Elasticity
b. Structure
c. Color
d. UV protection
?
Which of the following is not a function of the hypodermis?
a. Protects underlying organs
b. Helps maintain body temperature
c. Source of blood vessels in the epidermis
d. A site to long-term energy storage
?
In response to stimuli from the sympathetic nervous system, the arrector pili _______.
a. Are glands on the skin surface
b. Can lead to excessive sweating
c. Are responsible for goose bumps
d. Secrete sebum
The hair matrix contains _____.
a. The hair follicle
b. The hair shaft
c. The glassy membrane
d. A layer of basal cells
Eccrine sweat glands _____.
a. are present on hair
b. Are present in the skin throughout the body and produce watery sweat.
c. Produce sebum
d. Act as a moisturizer
Sebaceous glands ____.
a. Are a type of sweat gland
b. Are associated with hair follicles
c. May function in response to touch
d. Release a watery solution of salt and metabolic waste
Similar to the hair, nails grow continuously throughout our lives. Which of the following is furthest from the nail growth center?
a. Nail bed
b. Hypochium
c. Nail root
d. Eponychium
In humans, exposure of the skin to sunlight is required for _____.
a. Vitamin D synthesis
b. Arteriole constriction
c. Folate production
d. Thermoregulation
One of the functions of the integumentary system is protection. Which of the following does not directly contribute to that function?
a. Stratum lucidium
b. Desmosomes
c. Folic acid synthesis
d. Merkel cells
An individual using a sharp knife notices a small amount of blood where he just cut himself. Which of the following layers of skin did he have to cut ino order to bleed?
a. Stratum corneum
b. Stratum basale
c. Papillary dermis
d. Stratum granulosum
As you are walking down the beach, you see a dead, dry, shriveled-up fish. Which layer of your epidermis keeps you from drying out?
a. Stratum corneum
b. Stratum basale
c. Stratum spinosum
d. Stratum granulosum
If you cut yourself and bacteria enter the wound, which of the following cells would help get rid of the bacteria?
a. Merkel cells
b. Keratinocytes
c. Langerhans cells
d. Melanocytes
In general, skin cancers _____.
a. Are easily treatable and not a major health concern
b. Occur due to poor hygiene
c. Can be reduced by limiting exposure to the sun
d. Afect only the epidermis
Bedsores _____.
a. Can be treated with topical moisturixers
b. Can result from dep massages
c. Are preventable by eliminating pressure points
d. Are caused by dry skin
An individual has spent too much time sun bathing. Not only is his skin painful to touch, but small blisters have appeared in the affected area. This indicates that he has damaged which layers of his skin?
a. Epidermis only
b. Hypodermis only
c. Epidermis and hypodermis
d. Epidermis and dermis
After a skin injury, the body initiates a wound-healing response. The first step of this response is the foundation of a blood clot to stop bleeding Which of the following would be the next response?
a. Increased production of melanin by melanocytes
b. Increased production of conective tissue
c. An increase in Pacinian corpuscles around the would
d. An increased activity in the stratum lucidum
Squamous cell carcinomas are the second most common of the skin cancers and are capable of metastasizing if not treated. This cancer affects which cells?
a. Basal cells of the stratum basale
b. Melanocytes of the stratum basale
c. Keratinocytes of the stratum spinosum
d. Langerhans cells of the stratum lucidum
What determines the color of skin, and what is the process that darkens the skin when it is exposed to UV light?
Cells of the epidermis derive from stem cells of the stratum basale. Describe how the cells change as they become integrated into the different layers of the epidermis.
Explain the differences between eccrine and apocrine sweat glands.
Describe the structure and composition of nails.
Why do people sweat excessively when exercising outside on a hot day?
Explain your skin’s response to a drop in body core temperature.
Why do teenagers often experience acne?
Why do scars look different from surrounding skin?
