What do tension lines in the skin follow?
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What do tension lines in the skin follow?
The pattern of collagen fiber bundles in the dermis.
What are the two main plexuses involved in dermal circulation?
The cutaneous and subpapillary plexuses.
What do melanocytes produce?
Melanin.
What are the two types of skin?
Thin skin and thick skin.
What are melanocytes?
Cells that produce melanin, responsible for skin pigmentation.
What is the function of melanocytes?
To produce and store melanin.
What are hair follicles?
Structures in the skin from which hair grows.
Where is thin skin found?
Covers most of the body.
What is the integumentary system also known as?
Integument.
Where are melanocytes located in the skin?
In the stratum basale.
What do hair follicles associate with?
Accessory structures.
What percentage of body weight does the integumentary system account for?
16%.
How many layers does the epidermis have in thin skin?
Four layers.
What does the micrograph show?
The location and orientation of melanocytes in the stratum basale of a dark-skinned person.
What causes loss of skin turgor?
Dehydration.
What is the surface area of the integumentary system?
1.5−2 square meters.
What is the role of epidermal pigmentation?
It contributes to skin color.
Where is thick skin located?
Covers the palms of the hands and soles of the feet.
What is the deep network of vessels in the dermis called?
Cutaneous plexus.
What contributes to the formation of wrinkles in the skin?
Loss of elastic fibers in the dermis due to aging and UV radiation damage.
What are the two main components of the cutaneous membrane?
Epidermis and dermis.
What is the primary structure associated with hair growth?
Hair follicles.
What is carotene?
An orange-yellow pigment found in orange vegetables.
What is the primary focus of the content?
The structure of a nail.
What occurs during the inflammatory phase of skin injury repair?
Bleeding, swelling, and pain occur.
What is the primary function of nerve fibers in the skin?
To transmit information from sensory receptors, control blood flow, and adjust gland secretion rates.
What are first-degree burns?
Partial-thickness burns that damage only the surface of the epidermis, causing inflammation and minor pain.
How many layers does the epidermis have in thick skin?
Five layers.
What is the purpose of a scab during the migration phase of injury repair?
It stabilizes and protects the area.
Where is the cutaneous plexus located?
Along the border of the reticular layer of the dermis and the subcutaneous layer.
What are tension lines in the dermis?
Patterns produced by parallel bundles of collagen and elastic fibers.
What are the primary functions of hair?
To protect, cushion, and insulate.
What can cause stretch marks on the skin?
Excessive distortion of skin from pregnancy or weight gain.
What type of tissue makes up the epidermis?
Superficial epithelium.
What are nails made of?
Dead, keratinized epidermal cells.
Where does carotene accumulate in the body?
In epidermal cells, the dermis, and the subcutaneous layer.
What is the stratum spinosum?
A layer superficial to the stratum basale in the epidermis.
What does the diagrammatic view of a hair follicle typically illustrate?
The base of a hair follicle.
What type of section is mentioned in the content?
A longitudinal section.
What triggers inflammation during the inflammatory phase?
Mast cells.
What is the primary focus of the repair process in the integument?
To restore the integrity and function of the skin after injury.
What is Epidermal Growth Factor (EGF)?
A peptide growth factor that causes epithelial growth.
What does a superficial view of a nail show?
The outer appearance and structure of the nail.
How does aging affect blood supply to the dermis?
It is reduced, decreasing the ability to thermoregulate.
What symptoms are associated with second-degree burns?
Blistering, swelling, and pain.
What type of sensory receptors detect light touch?
Tactile (Meissner) corpuscles.
What is the structure that surrounds the hair root?
Hair follicle.
What do mammary glands produce?
Milk in females.
What role do macrophages play in the migration phase of injury repair?
They clean debris, dead cells, and pathogens.
What is the network of small vessels in the papillary layer of the dermis called?
Subpapillary plexus.
What is hair classified as?
A nonliving, long, cylindrical accessory structure.
What type of tissue is the dermis composed of?
Deep connective tissue.
What does the integumentary system contain?
Blood vessels and sensory receptors.
What is a consequence of aging on the dermis?
Loss of elastic fibers.
What are vellus hairs?
Soft, fine hairs that cover most of the body surface.
What is the function of tension lines?
They allow skin to resist applied forces.
What is the visible portion of the nail called?
Nail body.
What is the stratum corneum's role in water loss from the skin?
It is water resistant but not waterproof.
What can carotene be converted into?
Vitamin A.
How does scar formation vary?
Scar formation varies among individuals.
How does hair protect the body?
By guarding openings from particles and insects.
How many layers of keratinocytes are present in the stratum spinosum?
8 to 10 layers.
What are the main stages involved in the repair of skin injuries?
Hemostasis, inflammation, proliferation, and remodeling.
What is the primary function of the subcutaneous layer?
It stabilizes the position of the skin and connects the dermis to underlying tissues.
Where is EGF produced?
By the salivary glands and glands of the duodenum.
What happens to hair follicles as a person ages?
Their function declines, resulting in hair loss and thin hair.
What are the main components that contribute to dermal strength and elasticity?
Collagen fibers and elastic fibers.
What characterizes third-degree burns?
Full-thickness burns that destroy the epidermis, dermis, and extend into the subcutaneous layer, destroying hair follicles, nerves, and glands.
Where are tactile (Meissner) corpuscles located?
In the dermal papillae.
What is Rickets?
A disease caused by vitamin deficiency that results in weak and flexible bones.
Which cells migrate around the scab to begin epidermis repair?
Cells from the stratum basale.
What causes a contusion (bruise)?
Damage to blood vessels in the dermis.
What does a cross-sectional view of a nail reveal?
The internal structure and layers of the nail.
What is the function of ceruminous glands?
To produce cerumen (earwax) in the ear canal.
What are the two main parts of a hair?
Hair root and hair shaft.
What are some examples of accessory structures in the integumentary system?
Hair, hair follicles, nails, exocrine glands.
What is one function of the integumentary system related to vitamin synthesis?
Synthesis of vitamin D, which is converted to calcitriol, a hormone important for calcium metabolism.
Where does hair originate?
In the dermis.
What does the nail body cover?
The nail bed.
What are tactile (Merkel) cells responsible for?
They are sensory receptors for touch.
Why is vitamin A important?
It is required for the maintenance of epithelia and the synthesis of photoreceptor pigments in the eye.
Why do infants experience less scarring?
Infants have a more efficient healing process.
What is the subcutaneous layer also known as?
Hypodermis.
What are terminal hairs?
Heavy, pigmented hairs found on the head, eyebrows, and eyelashes.
How does a cut made parallel to tension lines heal?
It heals well with minimal scarring.
What is insensible perspiration?
Loss of water that diffuses across the stratum corneum and evaporates, approximately 500 mL per day.
What binds the keratinocytes in the stratum spinosum?
Desmosomes.
What is the dermis?
The deeper layer of skin located under the epidermis.
What role does inflammation play in skin injury repair?
It helps to prevent infection and initiates the healing process.
Is the subcutaneous layer considered part of the skin?
No, it is not part of the skin (the integument).
What is one laboratory use of EGF?
To grow skin grafts in tissue culture.
What role do hair play in sensory perception?
They serve as sensory receptors.
What is required for the repair of third-degree burns?
Skin grafts are needed as they cannot repair themselves.
What causes hair to become gray or white with aging?
Decreased melanocyte activity.
What do lamellar (Pacinian) corpuscles detect?
Deep pressure and vibration.
What types of cells migrate into the scab to repair the dermis and blood supply?
Fibroblasts and endothelial cells.
What is the characteristic of collagen fibers?
They are strong, can bend but do not stretch.
Where do hair follicles originate?
Deep in the dermis.
What causes the bending of bones in Rickets?
Abnormally weak and flexible bones under the weight of the body.
What is the role of cerumen?
It prevents foreign particles from reaching the eardrum.
What borders the nail body?
Lateral nail grooves and lateral nail folds.
Where is the junction located in relation to a hair?
Between the hair root and hair shaft.
What is the primary function of the integumentary system?
To protect the body from external damage and regulate various bodily functions.
What is stored in the dermis and subcutaneous layer?
Lipids.
Through which layer does hair project?
Through the epidermis.
What are sebaceous glands?
Glands in the skin that secrete oil (sebum).
What is a keloid?
A thick raised area of scar tissue covered by shiny smooth epidermis.
Where are tactile cells primarily found?
In hairless skin.
How are keratinocytes produced in the stratum spinosum?
By division of basal cells in the stratum basale, with some continuing to divide.
What type of tissue is the subcutaneous layer made of?
Loose connective tissue.
What structures does the dermis anchor?
Epidermal accessory structures such as hair follicles and sweat glands.
When do terminal hairs appear in the pubic area and armpits?
After puberty.
What happens when a cut is made perpendicular to tension lines?
It pulls open and scars more.
What occurs during the proliferation stage of skin repair?
New tissue forms, including collagen and new blood vessels.
What is the chemical name for Vitamin D?
Cholecalciferol.
What does EGF promote in basal cells?
Division of basal cells.
What is the primary composition of the subcutaneous layer?
Primarily composed of adipose tissue.
What is the primary structure associated with hair growth?
Hair follicles.
Can insensible perspiration be felt or prevented?
No, it cannot be felt or prevented.
What are the two types of melanin?
Pheomelanin (red-yellow) and eumelanin (brown-black).
What structural changes occur in the dermis due to aging?
The dermis thins and the elastic fiber network shrinks, causing sagging and wrinkling.
In which layer of the dermis are lamellar (Pacinian) corpuscles found?
In the reticular layer.
What is granulation tissue?
Tissue formed by the blood clot of the scab, fibroblasts, and the capillary network.
What is the reticular layer of the dermis?
The deeper layer of the dermis, located above the subcutaneous layer.
What is the hyponychium?
The thickened stratum corneum beneath the free edge of the nail.
What do sebaceous glands secrete?
Sebum, an oily substance that lubricates the skin.
How do collagen fibers affect tissue?
They add strength and limit flexibility to prevent tissue damage.
What are sebaceous follicles?
Large sebaceous glands that discharge sebum directly onto the surface of the skin.
What surrounds hair follicles?
A dense connective tissue sheath.
What are the structural changes associated with Rickets?
Changes in bone structure due to weakness and flexibility.
What happens to the epidermis as a person ages?
The epidermis thins and the connections between the dermis and epidermis weaken.
What can cause excessive scar tissue in dark-skinned individuals?
Dark skin can produce an excessive amount of scar tissue, leading to keloids.
What are the main components of the integumentary system?
Skin, hair, nails, and exocrine glands.
What types of stimuli can the integumentary system detect?
Touch, pressure, pain, vibration, and temperature stimuli.
What type of immune cells are found in the stratum spinosum?
Dendritic (Langerhans) cells.
What surrounds the hair root and the deeper portion of the hair shaft?
Internal root sheath.
Where on the body is hair not found?
On the lips, palms of the hands, sides of the fingers, sides and soles of feet, sides of toes, and portions of external genitalia.
What is one of the primary functions of the integumentary system?
Protection of underlying tissues and organs against impact, abrasion, fluid loss, and chemical attack.
What is the function of sebum?
To lubricate and protect the skin and hair.
What does the dermis contain?
A network of blood vessels and nerves.
What is the final stage of skin injury repair?
Remodeling, where the new tissue matures and strengthens.
What does the subcutaneous layer separate the integument from?
The deep fascia around organs such as muscles and bones.
What do tactile cells form together with sensory nerve endings?
Tactile discs.
What is the primary focus of the repair process in the integument?
To restore the integrity and function of the skin after injury.
What are the functions of subcutaneous fat?
Energy storage, insulation, and padding.
What factors determine hair color?
Pigment production by melanocytes, genes, environmental factors, and age.
How does EGF affect keratin production?
It accelerates keratin production.
Where is melanin produced?
By melanocytes.
How is Vitamin D produced in the body?
By epidermal cells in the presence of UV radiation.
What is the purpose of estimating the surface area of a burn?
To assess the severity and treatment needs of the burn.
How does aging affect hormone levels in relation to hair and body fat distribution?
Loss of hormones causes sex-specific hair and body fat distribution to fade.
What does a histological section of hair follicles show?
The longitudinal axis of hair follicles.
What is the stratum lucidum?
A layer of dead keratinocytes superficial to the stratum granulosum, found only in thick skin.
What happens to fluid loss if the stratum corneum is damaged?
Fluid loss increases, especially from burns.
What type of glands are sebaceous glands?
Holocrine glands.
What is the portion of hair that anchors it into the skin called?
Hair root.
What type of tissue makes up the reticular layer?
Dense irregular connective tissue.
Where is the hyponychium located?
Beneath the free edge, continuing past the nail bed.
Where are sebaceous follicles typically located?
In the dermis, associated with hair follicles.
What is the top layer of the dermis called?
Papillary layer.
What is the epidermis?
The top layer of the skin.
Where are sebaceous follicles located?
On the face, back, chest, nipples, and external genitalia.
What is the role of elastic fibers in the dermis?
They provide stretching and recoil, contributing to flexibility.
What is the root hair plexus?
A network of sensory nerves surrounding the base of hair follicles.
How does aging affect the number of dendritic cells in the skin?
The number of dendritic cells decreases, making the skin more prone to infection.
How does the integumentary system contribute to immune response?
It coordinates the immune response to pathogens and cancers in the skin.
What is the function of dendritic (Langerhans) cells in the stratum spinosum?
To defend against microorganisms and skin cancers.
What is a primary source of Vitamin A?
Carrots and other orange or yellow fruits and vegetables.
What are the two layers of the dermis?
The superficial papillary layer and the deeper reticular layer.
What extends from the skin surface to the hair matrix?
External root sheath.
What role do exocrine glands play in the integumentary system?
They secrete substances such as sweat and oil to help regulate temperature and protect the skin.
Where are sebaceous follicles typically located?
In association with hair follicles.
What substances are excreted by the integumentary system?
Salts, water, and organic wastes.
What are the main stages of skin injury repair?
Hemostasis, inflammation, proliferation, and remodeling.
What does the subcutaneous layer contain that is important for blood circulation?
Large arteries and veins, acting as a reservoir for blood.
What pigment do melanocytes synthesize?
Melanin.
Where does hair production begin?
At the hair bulb, at the base of the hair follicle.
What role does EGF play in epidermal development?
It stimulates epidermal development and repair.
What are melanosomes?
Intracellular vesicles that store melanin and transfer it to keratinocytes.
What happens to the repair rate of the skin as one ages?
The repair rate slows.
What does the rule of nines apply to?
Estimation of burn surface area in adults.
What organs convert Vitamin D into calcitriol?
The liver and kidneys.
What is the stratum corneum?
The top layer and exposed surface of the skin, consisting of 15−30 layers of keratinized cells.
What is sensible perspiration?
Water loss by excretion from sweat glands, which allows for cooling the body.
What do sebaceous glands produce?
An oily lipid secretion called sebum.
Where does the hair root begin?
At the base of the hair (hair bulb).
What are the main components found in the reticular layer?
Rich in collagen and elastic fibers.
What is jaundice and what causes it?
Jaundice is a condition where the liver is unable to excrete bile, leading to a buildup of yellow pigment in the body.
What type of tissue makes up the papillary layer of the dermis?
Areolar tissue.
What is the primary function of sebaceous glands?
To keep the skin and hair moisturized and protected.
What type of tissue composes the epidermis?
Stratified squamous epithelium.
What happens to Vitamin D production as we age?
Vitamin D production severely declines.
What do sweat glands produce?
A watery secretion called sweat.
What does skin turgor refer to?
The strength and flexibility of skin due to its water content.
What type of muscle is the arrector pili?
Involuntary smooth muscle.
What type of glands are eccrine sweat glands?
Coiled, tubular glands that secrete sweat directly onto the skin surface.
What is the nail root?
An epidermal fold where nail production occurs.
What is the clear layer wrapped in the connective tissue sheath called?
Glassy membrane.
What role does inflammation play in skin repair?
It helps to prevent infection and initiates the healing process.
How does hair contribute to the integumentary system?
It provides protection, regulates body temperature, and enhances sensory perception.
