Anatomy Ch. 5

Hair Shaft

Extends from this halfway point to the exposed tip of the hair.

Apocrine Sweat Glands

Found in the armpits, around the nipples, and in the pubic region. Secrete their products into hair follicles. These coiled, tubular glands produce a sticky, cloudy, and potentially odorous secretion. Relies on merocrine secretion. Begin secreting at puberty. Myoepithelial cells are here.

Thick Skin

Found on the palms of the hands and the soles of the feet.

Mammary Glands

Glands on the breasts, anatomically related to apocrine sweat glands. A complex interaction between sex hormones and pituitary hormones controls their development and secretion.

Hair Follicles

Hairs are nonliving structures produced in organs called ____ _______.

Epidermis

Superficial Epithelium

Myoepithelial Cells

Surrounds the secretory cells in apocrine sweat glands. They contract and squeeze the gland, causing the accumulated sweat to discharge into the hair follicles.

Stratum Granulosum

The "grainy layer". Consists of 3-5 layers of keratinocytes derived from the stratum spinosum. By the time cells are pushed into this layer, most have stopped dividing and have started making large amounts of the proteins keratin and keratohyalin.

Elastic and Collagen

The _____ fibers provide flexibility, and the ______ fibers limit that flexibility to prevent damage to the tissue.

Melanocytes

The brown tones of skin result rom the synthesis of pigment by these cells. Found in stratum basal, with cell processes extending into more superficial layers.

Hair Bulb

The bulging base of a hair follicle, where hair production begins.

Granulation Tissue

The combination of blood clot, fibroblasts, and an extensive capillary network at the base of a wound.

Medulla

The core of the hair, closer to the center of the hair matrix.

Cutaneous Plexus

The deeper network that lies along the border of the hypodermis with the reticular layer of the dermis. Tributaries of these arteries supply both the adipose tissues of the subcutaneous layer and the tissues of the integument.

Stratum Basale

The deepest layer of the epidermis, AKA the stratum germinativum. Hemidesmosomes attach the cells of this layer to the basement membrane that separates the epidermis from the areolar tissue of the dermis. Interlocks with underlying dermis increasing the strength of the bond between the epidermis and dermis.

Free Edge

The distal portion of the nail that continues past the nail bed and extends over the hyponychium.

Carotene and Melanin

The epidermis contains variable quantities of what 2 pigments?

Stratum Corneum

The exposed surface of both thick and thin skin. Normally contains 15-30 layers of keratinized cells. Water resistant, but not water proof.

Vellus Hairs

The fine "peach fuzz" hairs located over much of the body surface.

Hair Papilla

The hair bulb surrounds this, a peg of connective tissue containing capillaries and nerves.

Cortex

The intermediate layer of the hair, farther from the center of the hair matrix.

Calcitriol

The liver converts cholecalciferol into an intermediary product used by the kidneys to synthesize the hormone ______. Essential in the normal absorption of calcium and phosphorus in the small intestine.

Jaundice

The liver is unable to excrete bile, so a yellowish pigment accumulates in body fluids. In advanced stages, the skin and whites of the eyes turn yellow.

Lateral Nail Grooves and Lateral Nail Folds

The nail body is recessed deep to the level of the surrounding epithelium and is bordered on either side by ______ ____ ______ (depressions) and _____ ____ ____.

Eponychium

The portion of the stratum corneum of the nail root that extends over the exposed nail. AKA the cuticle.

Hair Root

The portion that anchors the hair into the skin. It begins at the base of the hair, hair bulb, and extends distally to the point at which the internal organization of the hair is complete, about halfway to the skin surface.

Sebum

The secreted lipid product from a sebaceous gland. A mixture of triglycerides, cholesterol, proteins, and electrolytes.

Epidermal ridges and dermal papillae

The stratum basale forms _______ _____, which extend into the dermis and are adjacent to dermal projections called ____ ______ that project into the epidermis.

Dermis

The underlying area of connective tissues.

Nail Body

The visible portion of the nails, covers the nail bed.

Insesnsible Perspiration

Unable to see or feel the water loss.

Collagen Fibers

Very strong and resist stretching, but they are easily bent or twisted.

The papillary layer and the deeper reticular layer.

What are the 2 major components of the dermis?

The cutaneous membrane and accessory structures.

What are the 2 major parts of the integumentary system?

Hair, exocrine glands, and nails.

What are the accessory structures of the integumentary system?

Apocrine and Merocrine

What are the two types of sudoriforous, or sweat, glands?

Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.

What is the strata in order from the basement membrane toward the free surface?

16%

What percentage of your body weight is made up by the integumentary system?

Cholelcalciferol, Vitamin D

When exposed to ultraviolet radiation, epidermal cells in the stratum spinosum and stratum basal convert a cholesterol-related steroid into ________, or ______ __.

Cyanosis

A bluish coloration of the skin.

Arrector Pili Muscle

A bundle of smooth muscle cells. Extends from the papillary layer of the dermis to the connective tissue sheath surrounding the hair follicle. When stimulated, it contracts, pulling on the follicle and forcing the hair to stand erect.

Rickets

A condition causing abnormal bone development, caused by inadequate amounts of cholecalciferol.

Abrasion

A deep scrape.

Albinism

A deficiency or absence of melanin production leads to this disorder.

Hair Matrix

A layer of epithelial cells at the base of the hair bulb in contact with the hair papilla produces the hair.

Tactile Disc

A merkel cell with a sensory nerve terminal. Sensitive to touch and when compressed release chemicals that stimulate their associated sensory nerve endings.

Epidermal Growth Factor (EGF)

A peptide growth factor. Produced by the salivary glands and glands of the duodenum. Promotes the division of basal cells in the stratum basal and stratum spinosum. Accelerates the production of keratin in differentiating keratinocytes. Stimulates epidermal development and epidermal repair after injury. Stimulates synthetic activity and secretion by epithelial glands.

Melanin

A pigment produced by melanocytes, pigment producing cells. The two types are a red-yellow form (pheomelanin) and a brown-black form (eumelanin).

Hemoglobin

A pigment, which is found in RBC's, that binds and transports oxygen in the bloodstream. When bound to oxygen it is bright red.

Halocrine Secretion

A secretion process that involves the rupture of a cell.

Incision

A slender, straight cut.

Keratinization

AKA cornification, the formation of protective, superficial layers of cells filled with keratin. Takes place on all exposed skin surfaces, except the anterior surfaces of the eyes.

Merocrine Sweat Glands

AKA eccrine sweat glands. Coiled, tubular glands that discharge their secretions directly onto the surface of the skin. More common sweat gland. Cools the surface of the skin to reduce body temperature. Excretes water and electrolytes. Provides protection from environmental hazards.

Basal Cells

AKA germinative cells, dominate the stratum basal. Stem cells that divide to replace the more superficial keratinocytes that are shed at the epithelial surface.

Senile Lentigos

AKA liver spots, are variably pigmented areas that develop on sun-exposed skin in older individuals with pale skin.

Cleavage Lines

AKA tension lines or langer lines. Collagen and elastic fibers arranged in parallel bundles oriented to resist the forces applied to the skin during normal movement. A cut parallel to these will usually remain posed and heal with little scarring.

Hyponychium

An area of thickened stratum corneum.

Nail Root

An epidermal fold not visible from the surface, where nail production takes place.

Carotene

An orange-yellow pigment that normally accumulates in epidermal cells. Most apparent in cells of the stratum corneum of light-skinned people, but it also accumulates in fatty tissues in the deep dermis and subcutaneous layer. Found in orange veggies, such as carrots and squash. Can be converted to Vitamin A.

The cutaneous membrane is made up of the ______ and the _____.

Epidermis and dermis

Melanocyte-Stimulating Hormone (MSH)

Causes a darkening of the skin, as if the individual has an extremely bronze tan. Some tumors affecting the pituitary gland result in the secretion of large amounts of this.

Dendritic Cells

Cells in the stratum spinosum that participate in the immune response. Have branching projections. Also known as langerhans cells. They stimulate defense against microorganisms that manage to penetrate the superficial layers of the epidermis and superficial skin cancers.

Stratum Spinosum

Consists of 8-10 layers of keratinocytes bound together by desmosomes. The "spiny layer" refers to the fact that the cells look like mini pincushions in standard horological sections. Contains dendritic cells.

Papillary Layer

Consists of areolar tissue. It contains the capillaries, lymphatic vessels, and sensory neurons that supply the surface of the skin. Has dermal papillae that project between the epidermal layer.

Thin Skin

Covers most of the body surface.

Hypodermis

Deep to the dermis, a loose connective tissue. AKA the superficial fascia or subcutaneous layer. Separates the integument from bone or muscle.

Reticular Layer

Deeper portion of dermis. It consists of an interwoven meshwork of dense irregular connective tissue containing both collagen and elastic fibers.

Contusion

Dermal blood vessels rupture, blood leaks into the dermis and the area develops the familiar "black and blue" color of a bruise.

Sebaceous Follicles

Discharge sebum directly onto the epidermis. Found on the face, back, chest, nipples, and external genitalia.

Cerumen

Ear wax.

Cuticle

Edge of the hair matrix, the surface of the hair.

Terminal Hairs

Heavy, more deeply pigmented, and sometimes curly.

Stratum Lucidum

In the thick skin of the palms and soles. The glassy, "clear" layer, covers the stratum granulosum. The cells in this ayer are flattened, densely packed, largely without organelles, and filled with keratin.

Vitiligo

Individuals lose their melanocytes, causing white patches on otherwise normal skin. Develops in about 1 % of the population.

Dermatitis

Inflammation of the skin that primarily involves the papillary layer.

Tyrosine and Melanosomes

Melanocytes manufacture both types of melanin from the amino acid _____ and package it into intracellular vesicles called _________.

Ceruminous Glands

Modified sweat glands in the passageway of the external ear. Secretes cerumen.

Keratinocytes

Most abundant epithelial cells, dominate the epidermis. These cells form several layers, or strata, and contain large amounts of the protein keratin.

Lunula

Near the root, blood vessels may be obscured, leaving this pale crescent.

Sebaceous Glands

Oil glands, are halocrine glands that discharge an oily lipid secretion into hair follicles.Produce large quantities of lipids as they mature. Release the lipid product through halocrine secretion.

Subpapillary Plexus

On reaching the papillary layer, the small arteries form this branching network. Provides arterial blood to capillary loops that follow the contours of the epidermis-dermis boundary. Connects to larger veins in the hypodermis.

Elastic fibers

Permit stretching and then recoil to their original length.

Sensible Perspiration

Produced by active sweat glands.

Nails

Protect the exposed dorsal surfaces of the tips of the finger and toes.

Lamellated (Pacinian) Corpuscles

Receptors sensitive to deep pressure and vibration, located in the reticular layer.

Tactile (Meissner's) Corpuscles

Receptors sensitive to light touch and located in the dermal papillae.

Root Hair Plexus

Sensory nerves surrounding the base of each hair follicle.

Lentigos

Similar o freckles but have regular borders and contain abnormal melanocytes.

Cutaneous Membrane

Skin

Merkel cells

Skin surfaces that lack hair also contain specialized epithelial tactile cells that are scattered among the cells of the stratum basal.

Freckles

Small, pigmented areas on relatively pale skin. Typically has an irregular border. They represent the areas serviced by melanocytes that are producing larger-than-average amounts of melanin.