The Integumentary System CH8

How do Apocrine sweat glands work?

Apocrine sweat glands Found in groin, nipples, and axillae. these glands secrete a thick sweat into ducts associated with hair follicles. Bacteria on the hair metabolize the sweat and produce the characteristic body oder of, for example, axillary sweat.

Thick-skinned areas, such as the plasm of the hands and oles of the feet, have_ ___ layers; thin-skinned areas have only _____

Five Four

The Dermis is divided in two layers: ________ and________.

papillary and reticular.

What are the characteristics of keratinocytes?

Keratinocytes are produced deep in the epidermis and pushed superficially toward the surface of the skin.

Which are 2 types of sweat glands?

- Merocrine Sweat glands - Apocrine sweat glands

Moving superficially from the basal lamina, which are the five layers of the epidermis?

- Stratum Basale (aka Stratum germinativum) - Stratum spinosum - Stratum Granulosum - Stratum lucidum - Stratum corneum

What is the papillary layer?

Although there is no distinct boundary between these layers, the superficial portion of the dermis is designated the papillary layer.

What is the function of the Arrestor Pili, in animals and in humans?

A smooth muscle called the arrestor pili muscle is attached to each hair follicle. When fur-covered animals are cold, this muscle contracts to raise the hair and trap a layer of warm air next to the skin. in humans the muscle has no known thermoregulatory use because humans do not have enough hair to gain an insulation benefit. we do have arrestor pili muscles though , and their contracting when we are cold is what produces "gooseflesh."

What causes the hair cell to harden and die?

Above the matrix, keratinizaton of the hair cells cause them to harden and die. The resulting hair shaft contains an outer cortex and an inner medulla.

Where is the reticular layer of the dermis located?

Deep to the papillary layer is he reticular layer of the dermis.

Which are the characteristics of nails?

Nails Protect the dorsal surface and tips of the fingers and toes, consists of tightly packed keratinized cells.

What is the result of prolonged of prolonged uv light exposure?

Prolonged exposure to UV light causes an increase in melanin synthesis resulting in a darkening , or tanning, of the integument.

Which are the characteristics of sebaceous follicles?

Sebaceous follicles Secrete sebum onto the surface of the skin to lubricate the skin and provide limited antibacterial action. these follicles are not associated with hair and are distributed on the face, most of the trunk, and the male reproductive organs.

Which are the characteristics of sebaceous glands?

Sebaceous glands Associated with hair follicles and secrete ht emily substance sebum, which coats the hair shafts and the epidermal surface to reduce brittleness and prevent excessive drying of the integument.

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Skin cancer// clinical application

Which are the characteristics is stratum lucidum?

Stratum lucidum In thick skin, a thin, transparent layer of cells. Lies superficial to the stratum granulosum. Only the thick skin of the palms and the soles of the feet have the stratum lucidum; the rest of the skin is considered thin and lacks this layer.

Which are the characteristics of the Stratum Spinosum? (in terms of Histology)

Stratum spinosum (Histology) When a slide of epidermal tissue is being prepared, cells in this layer often shrink, but the desmosome bridges between cells remain intact. This results in cells with a spiny outline; hence the name "spinousum."

Why is the skin classified as an organ?

The integument, or skin, is classified as an organ system because it is composed of many different types of tissues and organs.

What is the integumentary system?

The integumentary system is the most visible organ system of the human body.

Which are the characteristics of the nail root?

The nail root is at the base of the nail and is where new growth occurs. The lunula (luna- moon) is a whitish portion of the proximal nail body where blood vessels do not show through the layer of keratinized cells.

Which are the characteristics of the nail body?

The visible part of the nail, called the nail body, protects the underlying nail bed f the integument. Blood vessels underneath the nail body give the nail its pinkish color. The free edge of the nail body extends past the end of the digit.

Which are the two principal tissues in the integument?

There are two principal tissue layers in the integument: - a superficial layer of epithelium called the epidermis - a deeper layer of connective tissue, the dermis.

Which are the three major layers of hair?

Three major layers of hair are found in humans: - Terminal Hair - Vellus Hair - Intermediate Hair

What is the hyponychium?

Under the free edge of the nail is the hyponychium, a thicker region of the epidermis.

Sweat can be a _____ or a ____ substance.

thick or thin

What causes the hair to elongate?

Cells in the matrix undergo mitotic divisions that cause the hair to elongate.

What is the dermis and where is it located?

Dermis Location: Deep to the epidermis, second of the two layers of the integument. Thick layer of irregularly arranged connective tissue that supports and nourishes the epidermis and secures the integument to the underlying structures.

How is the skin formed?

Organs of the skin include oil-, wax- sweat-producing glands, sensory organs for touch; muscles attached to hair follicles; and blood and lymphatic vessels.

Which are the characteristics of vellus hair?

Vellus hair lightly pigmented and distributed over much of the skin as fine "peach fuzz."

Each hair has a_____ embedded deep in a hair follicle.

hair root

Where is the hair papilla located and which are its characteristics?

At the root tip is a hair papilla containing nerves, blood vessels, and their hair matrix, which is the living, proliferative part of the hair.

What are epidermal derivatives and when do they occur?

During embryonic development, the epidermis produces accessory integumentary structures called epidermal derivatives, which include oil and seat glands, hair, and nails.

What happens during the migration of keratinocytes?

During this migration the keratinocytes synthesize and accumulate the protein keratin, the internal organization of the cell is disrupted, and the cells die. These dry scalelike keratinized cells of the surface of the stratified squamous epidermis are resistant to dehydration and friction. Because of thee characteristics the integument is also called the cutaneous membrane.

What are some examples of epidermal derivatives?

Epidermal derivatives are exposed on the surface of the skin and project deep into the dermis. - Sebaceous glands - Sweat glands - Hair - Nails

Where are the dermal papillae located and what is their function?

Folds in the (dermis) tissue are called dermal papillae and project into the epidermis as the swirls of fingerprints. Within the dermal papillae are small sensory receptors for light touch, movement, and vibration, termed tactile corpuscles (aka Meissner's corpuscles)

How long does it take for a cell to migrate from the basal region to the surface of the epidermis.

From 15 to 30 days

Which are the characteristics of hair?

Hair Covers most of the skin, with only the lips, nipples, portions of the external genitalia, soles, palms, fingers, and toes being without hair.

Which are the characteristics of the hypodermis?

Hypodermis (aka Subcutaneous layer) Composed primarily of adipose tissue and areolar tissue. The hypodermic is NOT part of the integumentary system.

What is the function of keratohyalin?

Increases durability and reduces water loss form the integument surface.

Where are the intermediate hair located?

Intermediate Hair Hairs on the arms and legs.

What is the function of the papillary layer?

It consists o areolar tissue containing numbers collagen and elastic fibers.

What is the function of hair?

Serves a protective function. - It cushions the scalp and prevents foreign objects from entering the eyes, ears, and nose. - Hair also serves as a sensory receptor: wrapped around the base of each hair is a root hair plexus, a sensory neuron sensitive to moment of the hair .

What are the characteristics of the stratum basale?

Stratum Basale (aka Stratum germinativum) Layer just one cell thick that joins the basal lamina of the epidermis to the upper surface of the dermis. The cells in this stratum are stem cells and so are in a constant state of mitosis, replacing cells that have rubber off the epidermis surface. Other cells in this layer, the melanocytes, produce the pigment melanin, which protects deeper cells from the harmful effect of ultraviolet radiation form the sun.

What are the characteristics of stratum granulosum?

Stratum Granulosum As cells from the stratum germinative are pushed superficially, they sent he size the protein keratohyalin, which increases durability and reduces water loss form the integument surface. Keratohyalin granules stain dark and give this layer its color (darker).

What are the characteristics of stratum spinosum?

Stratum Spinosum Consists of five o seven layers of cells, interconnected by strong protein molecules between cell membranes, forming cell attachments called desmosomes.

Which are the characteristics of stratum corneum?

Stratum corneum (corneum - horn) Most superficial layer of the epidermis and contains many layers of flattened, dead cells. As cells from the stratum granulosum migrate superficially, keratohyalin granules are converted to the fibrous protein keratin. Cells in the stratum cornem also accumulate the yellow-orange pigment carotene, which is common in light-skinned individuals.

Which are the characteristics of sweat glands?

Sweat Glands (aka sudoriferous glands) Scattered throughout the derma of most of the integument. they are exocrine glands that secrete their liquid either into wear ducts leading to the skin surface or into sweat ducts leading to hair follicles.

What is the function of sweat glands?

Sweat glands in the skin cool the body to regulate the body temperature.

Which are some examples of terminal hair ?

Terminal Hair thick, heavy hairs on the scalp, eyebrows, and eyelashes.

What is the cuticle?

The epidermis around the nail is the eponychium (epi - over, onyx - nail), what is commonly called the cuticle. At the cuticle the epidermis seals the nail with the nail groove and the raid nail fold.

The epidermis consists of. ...?

The epidermis consists of a stratified squamous epithelium organized into many distinct layers, or strata of cells.

Which are the characteristics of the reticular layer of the dermis?

This layer is distinguished by a meshwork of thick bands of collagen fibers in dense irregular connective tissue. Hair follicles and glands form the epidermis penetrate deep into the reticular layer. sensory receptors in the layer, called lamellated corpuscles (Pacinian corpuscles), detect deep pressure.

How do merocrine sweat glands work?

To cool the body, merocrine sweat glands secrete onto the body surface a thin sweat containing electrolytes, proteins, urea, and other compounds. The sweat absorbs body heat and evaporates from the skin, cooling the body. It also contributes to body odor because of the presence of urea and other wastes. Merocrine glands, also called eccrine glands, are not associated with hair follicles and are distributed throughout most of the skin.

Where is vitamin D3 manufacture and which is its function?

When exposed to sunlight, the integument manufactures vitamin D3, a vitamin essential in calcium and phosphorus balance.