Integumentary System Review

Scar

Variable area of scar tissue formed during tissue repair

Keloid

Thickened area of scar tissue covered by a shiny, smooth epidermal surface

Sagittal

Parallel to the long axis

Midsagittal

Divides the body into equal left and right halves

Integumentary System

Consists of the cutaneous membrane and accessory structures

Cutaneous membrane

The skin, made up of the epidermis and dermis

Accessory structures

Nails, hair, and exocrine glands

Functions of the integumentary

Protection, temperature maintenance, nutrient synthesis and storage, sensory reception, excretion and secretion

Epidermis

Outermost layer of the skin, consisting of 5 strata: basale, spinosum, granulosum, lucidum, and corneum

Dermal blood cells

Provide nutrients to epidermal cells through dermal papillae

Carotene

Orange-yellow pigment accumulated in epidermal cells, can be converted into vitamin A

Melanin

Brown, yellow-brown, or black pigment produced by melanocytes, protects against UV radiation

Freckles

Small pigmented spots caused by greater-than-average melanin production, not cancerous

Dilation of blood cells

Causes skin to become flushed and red when body temperature rises

Cyanosis

Bluish coloration of the skin due to extreme cold or circulatory/respiratory disorders

Basal cell carcinoma

Most common skin cancer, looks like a waxy bump, originates from stratum basale

Squamous cell carcinoma

Less common skin cancer, involves superficial layers of epidermal cells

Malignant melanoma

Extremely dangerous skin cancer, begins from a mole, grows rapidly and metastasizes

Papillary layer

Consists of areolar tissue that supports and nourishes the epidermis

Reticular layer

Consists of dense, irregular connective tissue, provides flexibility and limits damage to the tissue

Hypodermis

Connective tissue layer that attaches the dermis to underlying tissues, stabilizes the skin

Hair follicle

Contains dead keratinized cells

Arrector pili muscles

Muscles that pull on the hair follicle, causing the hair to stand up

Hair loss

Caused by drugs, dietary factors, radiation, fever, stress, hormonal factors

Hair color

Determined by type and amount of pigment produced by melanocytes at the hair papilla

Sebaceous glands

Exocrine glands that produce sebum, lubricates hair and skin, inhibits bacterial growth

Apocrine sweat glands

Secrete products into hair follicles in armpits, around nipples, and in pubic regions

Merocrine sweat glands

Discharge secretions directly onto the surface of the skin

Nail

Consists of nail plate, nail bed, nail root, and nail matrix

Stages of skin repair

1) Blood clot forms, 2) Fibrin network forms, 3) Epidermal cells migrate and debris is cleared, 4) Scar tissue forms

Scab

Temporarily restores integrity of the epidermis and restricts entry of microorganisms

Abrasion

Superficial skin injury that heals longer and involves a larger area

Granulation tissue

Combination of blood clots, fibroblasts, and capillaries, involved in tissue repair

Collagen

Principal protein of skin, ligaments, cartilage, bone, and connective tissue

Age-related changes in the integumentary system

Skin injuries and infections become more common, immune system sensitivity decreases, muscles weaken, bone strength decreases, sensitivity to sun exposure increases, skin becomes dry and wrinkled, hair thins and changes color, ability to lose heat decreases, skin repairs proceed more slowly

Ventral

Belly side of the body

Dorsal

Back side of the body

Inferior

Below; at a lower level

Distal

Away from an attached base

Superficial

At, near, or relatively close to the body surface

Keratin

Protein produced in the stratum granulosum, provides structure to skin, hair, calluses, and nails

Constriction of blood cells

Causes skin to become pale

1st-degree burn

Superficial burn that affects only the epidermis

2nd-degree burn

Burn that affects the epidermis and may extend into the dermis

3rd-degree burn

Burn that affects all layers of the skin and underlying tissues

Transverse

Perpendicular to the long axis

Frontal

Divides the body into anterior and posterior portions

Anterior

Front side of the body

Posterior

Back side of the body

Cranial

Relating to the head

Superior

Above; at a higher level

Caudal

Relating to the tail

Medial

Toward the body's longitudinal axis

Lateral

Away from the body's longitudinal axis

Proximal

Toward an attached base

Deep

Farther from the body surface