Human Anatomy Chapter 6

Freckle

A concentration of melanin in one spot.

Phagocytic cells that occupy the epidermis are called?

Dendritic cells

What cell to cell structures hold the cells of the stratum spinosum?

Desmosomes

Sweat gland involved in temperature control

Eccrine sweat gland

Jaundice

the tissues become yellowed, is almost diagnostic for liver disease.

Stratum Corneum

- Consists of 20 to 30 cell layers. -Often accounts for bulk of epidermal thickness -Cells are flat, dead and scale-like

Sebum

-is the product of sebaceous glands, it is a mixture of oily substances and fragmented cells that acts as a lubricant to keep the skin soft and moist ( a natural skin cream and keeps the hair from becoming brittle.

Medulla

-refers to the middle of something and derives from the Latin word for marrow

Stratum spinosum

-several rows/layers of cells -Called "Spiny" layer because of the resulting artifact of desmosomes holding tight while the cells separate. -Also contain prominent amounts of Langerhans (dendritic) cells; more than basale

Hair

-structure consisting of three parts: medulla, central region,surrounded by the cortex, and protected by the cuticle.

Cortex

-the outermost or superficial layer of an organ

Hair root

-the portion of the hair within the follicle

Hair shaft

-the portion projecting from the scalp surface

Describe two integumentary system mechanisms that help in regulating body temperature:

1. Eccrine sweat gland-cool by evaporation 2. Superficial blood vessels-release heat through conduction

List of sensory receptors found in the dermis of the skin?

1. Free nerve endings (pain receptors) 2. Lamellar corpuscles 3. Hair follicle receptors (hair root plexus)

Fibers in the dermis are produced by:

Fibroblasts.... also responsible for collagen and matrix

dermal papillae or just "Papilla"

Small nipple of dermal tissue in the base of follicle.

With what substance in the bond paper does the iodine painted on the skin react?

Starch

Layer of translucent cells containing dead keratinocytes

Stratum Lucidum

The most superficial layer of the epidermis is?

Stratum corneum

Two layers of dead cells

Stratum corneum

Which layer is present in thick skin, but not in thin skin?

Stratum lucidum

Major skin area that protects derivatives (nails and hair)

epidermis as a whole

The skin has two distinct regions. The superficial layer is the ____, and the underlying connective tissue, the ______.

epidermis; dermis

"sports" a lunule and cuticle

nail

skin/ integument

organ system:complex. Covers external body, has multiple functions.

Dermal layer responsible for fingerprints

papillary layer

Keratin

A protein-based substance secreted by cells of the epiderms as they migrate outward. The keratin makes the cells tougher (better able to withstand abrasion) and helps make the skin waterproof.

epidermis

Composed of epithelial cells, is the outermost protective shield of the body. A keratinized stratified squamous epithelium consisting of 4 distinct cell types and 4 or 5 distinct layers.

______ granules contain glycolipids that prevent water loss from the skin

Lamellated

These cells produce a brown to black pigment that colors the skin and protects DNA from ultraviolet radiation damage. The cells are ______.

Melanocytes

Produces an accumulation of oily material that is known as a blackhead

Sebaceous gland

Root of nail

The part that is embedded in the skin and adheres to an epithelial nail bed

Why can fingerprints be used to identify individuals?

The pattern of your epidermal ridges is unique and does not change during your lifetime. Everyone fingerprint was made different, therefore this is a useful way for people to identify one another.

What substance is manufactured in the skin (but is is not a secretion) to play a role elsewhere in the body?

Vitamin D

hypodermis/ superficial fascia

aka subcutaneous layer; layer of adipose/*fat located under the dermis of the skin. The hypodermis helps to insulate the body and protects underlying muscles and other structures.

Tiny muscle, attached to hair follicles, that pull upright during fright or cold

arrector pili muscle

Specialized nerve ending that respond to temperature, touch, etc.

cutaneous receptors

The portion of hair that you see that projects from the scalp surface is known as the? a. bulb b.matrix c.root d.shaft

d. shaft

All of the following are functions of the skin except: a. excretion of body wastes b. insulation c. protection from mechanical damage d. site of vitamin A synthesis

d. site of vitamin A synthesis

Has abundant elastic and collagenic fibers

dermis as a whole

Vascular region of the skin

dermis as a whole

Primarily dead/keratinized cells

hair and nails

Nail

hornlike derivatives of the epidermis

Found everywhere on the body except the palms of hands and soles of the feet

sebaceous glands

Secretes a lubricant for hair and skin

sebaceous glands

nail folds

skin folds that overlap the borders of the nail

Epidermal layer exhibiting the most rapid cell division

stratum basale

Location of melanocytes and tactile epithelial (MERKLE) cells

stratum basale

Layer including scalelike dead cells, full of keratin, that constantly slough off

stratum corneum

Area where weblike pre-keratin filaments first appear

stratum spinosum

Layer of mitotic filled with intermediate filaments

stratum spinosum

Free edge of nail

the portion of the nail the grows out away from the body

Hyponychium of nail

the region beneath the free edge of the nail

Nail plate of nail

the visible attached portion

Bedsores (decubitus ulcers)

- occur in the bed ridden patients who are not turned regularly enough; the weight of the body exerts pressure on the skin, especially over bony projections (hips, heels, knees, etc) which leads to restriction of the blood supply and tissue death.

Reticular in dermis

-Deepest layer of the skin -Contains many arteries and veins, sweat and sebaceous glands -Contains pressure receptors called Pacinian corpuscles in hairless skin (lamellar corpuscles)

hair follicle

-Epidermal AND Dermal Cells -Thick basement membrane -Small nipple of dermal tissue in the base = dermal papillae or just "Papilla"

Sweat (Sudoriferous) Glands

-Exocrine Glands -Secrete water, salts and urea. (Varies by type) -Outlets called "pores." -Widely distributed throughout body

Eccrine gland (merocrine sweat glands)

-Important for thermoregulation, evaporating water cools skin. -Only secretes water, salts and urea.

Sebaceous Glands

-Nearly all skin except Palms and Soles -Make SEBUM a mix of oil and fragmented cells that lubricates the skin like natural "skin cream" -Particularly active during puberty -Acne; an active infection of the sebaceous glands

Stratum Granulosum

-Only 1-3 Rows/Layers of Cells -Contain lamellated granules; which supply waterproofing glycolipid into extracellular space and keratohyalin granules which help form keratin fibrils -The upper layer is dying or dead cells.

Stratum Lucidum

-Only present in Soles of Feet or Palms of hand! -Very thin; "Clear" (lucid), flattened, dead cells -5th layer of epithelium- responsible for fingerprints

Apocrine

-Predominantly in axilla and genital areas -Along with water, salts and urea secretes a milky protein and fat rich substance. -Maybe analogous to pheromone glands of other animals

Cutaneous glands

-Sebaceous Glands (oil) -Sweat (sudoriferous) Glands: --Eccrine --Apocrine

Stratum basale

-Single row of cells immediately adjacent to the dermis -Constantly undergoing mitotic cell division, millions daily -Alternate name- stratum germinativum -Merkle cells! -10-25% melanocytes

Arrector Pili muscle

-Smooth Muscle Bands -Connect follicle to papillary dermis -Cold, Fright....pulls upright -Also exert pressure on the sebaceous glands to expel sebum

Melanocytes

-Spidery black cells that produce the brown to black pigment called melanin. -Melanin production increases when exposed to sunlight -Melanin provides protective pigment umbrella over the nuclei, shielding the genetic material..DNA.. from the damaging effects of the ultraviolet radiation.

Papillary in dermis

-Superficial layer -Has fingerlike projections -Attaches to epidermis above -Produces finger and palm prints -Contains tactile pain (free nerve ending) and touch receptors called Meissner's corpuscles in hairless skin (tactile corpuscles... MERKLE!)

hair bulb

-a collection of well nourished germinal epithelial cells at the basal end of the follicle

Blackheads

-are accumulations of dried sebum and melanin from epithelial cells in the oil duct.

Acne

-is an active infection of the sebaceous glands.

Cells and Layers from deep (Dermis) to superficial surface of skin:

1. Stratum basale 2. Stratum spinosum 3. Stratum granulosum 4. Stratum corneum

Four protective functions of the skin are?

1. prevents desiccation 2. prevents bacterial invasion 3. protects against thermal damage 4. protects against UV radiation.

The skin of the epidermis contains ___ layers? In stratum lucidum?

4 layers, 5 in stratum lucidum-palms of hands, soles of feet

Keratinocytes

Aka keratin cells. The most abundant epidermal cells. Their chief role is to produce the intermediate filament called keratin. Arise from the deepest layer of epidermis called the stratum basale (basal layer). This layer is very mitotic—as the keratinocytes proceed up through the more superficial layers, start to make more and more keratin.

Dendritic cells

Also called Langerhans cells, these phagocytic cells (macrophages) play a role in immunity.

Circle the correct answer: Eccrine/Apocrine glands are found primarily in the genital and axillary areas.

Apocrine

Glands that respond to rising androgen levels are the _______ glands

Apocrine

Less numerous type of perspiration-prouducing gland; found mainly in the pubic and axillary regions

Apocrine glands

Fingerprints

Arches, loops, and whorls

Cyanosis

Blue tint to skin, means lack of oxygen in the blood

Addison's disease

Bronzing of the skin hints that the person's adrenal cortex is hypo active.

_____ is the yellow-orange pigment found in the stratum corneum and the hypodermis.

Carotene

Sheath formed of both epithelial and connective tissue

Hair follicle

A unique touch receptor formed from a stratum basale cell and a nerve fiber is a?

Merkle cell

Tactile epithelial cells MERKLE CELLS

Occasional spiky hemispheres that, in conjunction with disklike sensory nerve endings, form sensitive touch receptors located at the epidermal-dermal junction.

Layer of areolar connective tissue

Papillary dermis

Circle the correct answer: The ducts of the sebaceous/sweat glands usually empty into a hair follicle but may also open directly onto the skin surface.

Sebaceous

True/False: Nails are hornlike derivatives of the epidermis.

True

Eponychium of nail

the thick proximal nail fold, commonly called the cuticle

dermis

thick layer of connective tissue containing collagenous & elastic fibers; composed of 2 layers (papillary-closest to epidermis & reticular)

The two basic tissues of which the skin is composed are dense connective tissue, which makes up the dermis, and __1__, which forms the epidermis. Most cells of the epidermis are __2__. The protein __3__ makes the dermis tough and leather like. The specialized cells that produce the pigments that contribute to skin color are called __4__.

1. stratified squamous epithelium 2. Keratinocytes 3. Keratin 4. Melanocytes

Layers of the Dermis

1.) Papillary "nipplelike" 1.) Reticular Both: -Highly Vascularized -With many elastic and collagen fibers; relating to "wrinkles" -Like other Connective Tissue: fibroblasts, adipose cells, and macrophages -Dermal vessels play important part in thermoregulation; dilating to dissipate heat and constricting to preserve heat. -Also contains rich supply of lymphatic vessels