AP 103: Chapter 5 The Integumentary System

Scar Tissue

The formation of this rather inflexible, fibrous, non-cellular _______ ______ can be considered a practical limit to the repair process.

Basal Cell Carcinoma

The most common form of skin cancer, which often looks like a waxy bump. This cancer originates in the stratum basale layer.

Cortex

The underlying layer beneath the cuticle (hair)

Keloid

Thickened area of scar tissue.

Lunula

Underlying blood vessels give nail its pink appearance, but near the root these vessels may be obscured, leaving a pale crescent known as the ________.

Nail Root

Where nail production occurs. Not visible from the surface

Stratum Spinosum

layer above stratum basale

Stratum Lucidum (clear layer)

Covers the stratum granulosum. The cells in this layer are flattened, densely packed, and filled with keratin.

Dermal Papillae

Dermal projections called ________ ________ extend upward between the adjacent epidermal ridges. The combination of ridges and papillae increases the surface area for diffusion between the dermis and epidermis.

sebaceous glands (oil glands)

Discharge an oily lipid secretion into hair follicles or, in some cases, onto the skin. The gland cells produce large quantities of lipids as they mature. The lipid is released through holocrine secretion, a process that involves the rupture and death of the cells.

Malignant Melanomas

Extremely dangerous form of cancer. Usually begins from a mole but may appear anywhere in the body. In this condition, cancerous melanocytes grow rapidly and metastasize through the lymphatic system.

alopecia

Hair loss

Hair Growth Cycle

Hairs grow and are shed according to a _______ _______ ________ based on the activity level of hair follicles.

Keratinized (Cornified)

15-30 layers of flattened and dead epithelial cells that have accumulated large amounts of keratin, such cells are said to be __________.

Arrector Pili

A bundle of smooth muscle cells forms the _________ _______ muscle, which extends from the papillary dermis to the connective tissue sheath that surrounds each hair follicle. When stimulated, the arrector pili pulls on the follicle, forcing the hair to stand up. Contraction may be caused by emotional states (such as fear or rage) or a response to cold, producing "goose bumps."

Hair Papilla

A peg of connective tissue containing capillaries and nerves.

Cuticle

A portion of the stratum corneum of the fold extends over the exposed nail nearest the root, forming the __________.

Cutaneous Membrane

AKA skin, is an organ composed of the superficial epithelium, or epidermis, and the underlying connective tissues of the dermis.

Stratum Corneum

At the exposed surface of the skin is the __________ __________.

Cyanosis

Bluish discoloration of the skin, most apparent in areas with thin skin such as the lips, ears, or beneath the nails. It can be a response to extreme cold or a result of circulatory or respiratory disorders, such as heart failure or severe asthma.

Melanin

Brown, yellow-brown, or black pigment produced by melanocytes. Helps prevent skin damage by absorbing UV radiation before it reaches the deep layers of the epidermis and dermis.

Merocrine Sweat Glands

Coiled tubular glands that discharge their secretions directly onto the surface of the skin. They are far more numerous and widely distributed than apocrine glands. The primary function of _______ _______ ________ is to cool the surface of the skin and lower body temperature.

Accessory Structures

Include hair, nails, and a variety of exocrine glands.

Albinism

Individual has a normal amount of melanocytes, but no melanin is produced.

acne

Individuals with large sebaceous glands may be especially prone to develop _______ during adolescence. In ______, sebaceous ducts become blocked and secretions accumulate, causing inflammation and a raised "pimple."

Third Degree Burn

Killed: all epidermal and dermal cells Injured: hypodermis and deeper tissues and organs

Second Degree Burn

Killed: superficial and deeper cells of epidermis; dermis may be affected Injured: damage may extend into reticular layer of the dermis, but many accessory structures (hair follicles and glands) are unaffected

First Degree Burn

Killed: superficial cells of the epidermis Injured: Deeper layers of epidermis, papillary dermis

Sebaceous Follicles

Large sebaceous glands that discharge sebum directly onto the skin. They are located on the face, back, chest, nipples, and external genitalia.

Sebum

Lubricates the hair and skin and inhibits the growth of bacteria.

Cutaneous Plexus

Network of blood vessels in the hypodermis that supplies blood to the skin. Its branches within the dermis provides nutrients and oxygen and removes carbon dioxide and waste products.

Carotene

Orange-yellow pigment that normally accumulates in epidermal cells. ________ pigments are present in a variety of orange-colored vegetables, such as carrots and squashes. _________ can be converted to vitamin A, which is required for the normal maintenance of epithelial tissues and the synthesis of photoreceptor pigments in the eye.

Hair

Projects above the surface of the skin almost everywhere except the sides and soles of the feet, the palms of the hands, sides of the fingers and toes, the lips, and portions of the external genital organs.

Nails

Protect the dorsal surfaces of the tips of the fingers and toes. They also help limit distortion of the digits when they are subjected to mechanical stress. For example, when you run or grasp objects.

Apocrine Sweat Glands

Secrete their products into hair follicles in the armpits, around the nipples, and in the pubic region.

Hirsutism

Women that have excessive hair

Freckles

Small pigmented spots that appear on the skin of pale-skinned individuals. _________ represent areas of greater-than-average melanin production. They tend to be most abundant on surfaces exposed to the sun, such as the face.

Hair Follicles

Structures that produce hair.

Melanocytes

Synthesizes melanin, a brown, yellow-brown, or black pigment that colors the epidermis. Found in the stratum basale.

Nail Bed

The body of the nail covers an area of epidermis called the ______ ______.

Granulation Tissue

The combination of blood clot, fibroblasts, and an extensive capillary network is called ___________ ____________.

Stratum Germinativum (Stratum Basale)

The deepest epidermal layer. The cells of this layer are firmly attached to the basement membrane by hemidesmosomes. The basement membrane separates the epidermis from the loose connective tissue of the adjacent dermis

Five Functions of the Integument

1. Protection: the skin covers and protects underlying tissues and organs from impacts, chemicals, and infections, and it prevents the loss of body fluids. 2. Temperature Maintenance: The skin maintains normal body temperature by regulating heat exchange with the environment. 3. Synthesis and Storage of Nutrients: The epidermis synthesizes vitamin D3, a steroid building block for a hormone that aids calcium uptake. The dermis stores large reserves of lipids in adipose tissue. 4. Sensory Reception: Receptors in the integument detect touch, pressure, pain, and temperature stimuli and relay that information to the nervous system. 5. Excretion and Secretion: Integumentary glands excrete salts, water, and organic wastes. Additionally, specialized integumentary glands of the breasts secrete milk.

Nail body

Consists of a dense mass of dead keratinized cells. The _______ ______ is recessed beneath the level of the surrounding epithelium.

Papillary Layer

Consists of areolar tissue that supports and nourishes the epidermis. This region contains the capillaries and nerves supplying the surface of the skin.

Keratin

Extremely durable and water-resistant. In humans, ________ not only coats the surface of the skin but also forms the basic structure of hair, calluses, and nails.

Ultraviolet Radiation

Found in sunlight. A small amount is beneficial because it stimulates the synthesis of vitamin D3 in the epidermis. Too much produces immediate effects of mild or even serious burns.

Cuticle

Found in the hair, made up of an overlapping shingle-like layer of cells.

Epidermal Ridges

Found in the stratum basale. Extends into the dermis, increasing the area of contact between the two regions.

Basal Cells (germinative cells)

Found in the stratum basale. The continuous division of these cells replaces cells that are lost or shed at the epithelial surface.

Hair Matrix

Hair is formed by the repeated divisions of epithelial stem cells in the ________ ________ surrounding the hair papilla.

Stratum Granulosum

Layer above stratum spinosum. Once daughter cells reach this layer they stop dividing and begin making large amounts of the protein keratin.

Reticular Layer

Layer deep to the papillary layer, consists of an interwoven meshwork of dense, irregular connective tissue. Both elastic fibers and collagen fibers are present. The elastic fibers provide flexibility, and the collagen fibers limit that flexibility to prevent damage to the tissue.

Squamous Cell Carcinoma

Less common form of skin cancer that involves more superficial layers of epidermal cells.

Medulla

Makes up the core of the hair. Contains a flexible soft keratin; the cortex and cuticle contain thick layers of hard keratin, which give the hair its stiffness.