Principles of Anatomy and Physiology: Chapter 5: The Integumentary System Flashcards

Group of tissues that performs a specific function

Group of organs working together toward common goals

The skin and its derivatives, such as:

• Hair
• Nails
• Glands
• Nerve endings

Many interrelated factors affect both appearance and health of skin

Skin

The medical specialty that deals with diagnosing and treating skin disorders

• Epidermis--the outer, thinner portion, composed of epithelium
• Dermis--the inner, thicker portion, composed of connective tissue
• Subcutaneous (hypodermis)--superficial fascia--underlies from dermis

• Regulate body temperature
• Protection (Ex. Burns)
• Sensation (Ex. Pain)
• Excretion (Ex. Sweat)
• Immunity (Ex. Mechanical barrier)
• Blood reservoir (Ex. Blood vessels stored in skin)
• Synthesis of vitamin D (Ex. Sunlight, consumption of milk)

Composed of stratified squamous epithelium

• Keratinocytes
• Melanocytes
• Langerhans cells
• Merkel cells

• Stratum basale (stratum germinativum)
• Stratum spinosum
• Stratum granulosum
• Stratum lucidum (only palms and soles)
• Stratum corneum

Continuous cell division and produces all other layers

Continuously shed and replaced by cells from deeper strata

Replacement of cell contents with the protein keratin, occurs as cells move to the skin surface over 2-4 weeks

Hormone that stimulates growth of epithelial and epidermal cells during tissue development, repair, and renewal

Composed of connective tissue containing collagen and elastic fibers and has two regions

• Papillary layer
• Reticular layer

Areolar connective tissue containing fine elastic fibers, dermal papillae, and corpuscle of touch (Meissner's corpuscles)

Irregular connective tissue containing collagen and elastic fibers, adipose tissue, hair follicles, nerve, sebaceous (oil) glands, and ducts of sudoriferous (sweat) glands

Collagen and elastin fibers

Subcutaneous layer (hypodermis, or superficial fascia)

Indicate the direction of collagen fiber bundles in the dermis and are considered in making surgical incisions

• Melanin
• Carotene
• Hemoglobin (in blood capillaries) - in the dermis

• Cyanosis
• Jaundice
• Erythema

Respiratory and

Yellowing of sclera of eyes and can be cured by UV radioactive light or sunglight

Superficial reddening of the skin, usually in patches, as a result of injury or irritation causing dilation of blood capillaries

Increase friction for better grasping ability and provide the basis for fingerprints and footprints. The ridges typically reflect contours of the underlying dermis

The blood pressure in the capillary beds in the papillae

New skin cannot regenerate without a skin graft

The individual himself or from an identical twin

Autologous skin transplantation

Structures developed from the embryonic epidermis such as:

• Hair
• Skin glands (sebaceous, sudorifous, and ceruminous)
• Nails

• Epidermal growths that function in protection and reduction in heat loss
• Consist of a shaft above the surface, a root that penetrates the dermis and subcutaneous layer, and a hair follicle
• Associate with hairs are sebaceous (oil) glands, arrectores pilorum muscles, and root plexuses
• New hairs develop from cell division of the matrix in the bulb; hair replacement and growth occur in a cyclic pattern
• Color is primarily due to melanin (black, brown, red, blonde)
• Hormones (androgens) can stimulate growth in males and females or somehow inhibit it in genetically predisposed males (male-pattern baldness)--Drug treatment

• Sebacous (oil) glands
• Sudoriferous (sweat) gland
• Ceruminous glands

Usually connected to hair follicles; they are absent in the palms and soles

• Produce sebum, which moisten hairs, waterproofs and softens the skin, and inhibits bacterial growth
• Enlarged glands may produce blackheads, pimples, and boils

Divided into apocrine and eccrine types

• Eccrine sweat glands have an extensive distribution; their ducts terminate at pores at the surface of the epidermis
• Apocrine sweat glands are limited in distribution to the skin of the axilia, pubis, and areolae; their ducts open into hair follicle to drain
• Produce perspiration (sweat), which assists in maintaining body temperature and also carries small amounts of wastes to the surface

Modified sudoriferous glands that produce a waxy substance called cerumen. They are found in the external auditory meatus

• Candle
• Hydrogen peroxide
• Q-tips
• Leave it alone; it falls out within 7-10 days

Hard, keratinized epidermal cells over the dorsal surfaces of the terinal portions of the fingers and toes

• Principal parts of a nail are the body, free edge, root, lunula, eponychium, and matrix
• Cell division of the matrix cells produce new nails
• Help grasping and manipulating small objects in various ways and provide protection against trauma to the ends of the digits

• Abrasions
• First degree or second degree burns

• Central portion of the would usually extends deep down to the dermis, wheras the wound edges usually involve only superficial damage to the epidermal cells
• Repaired by enlargement and migration of basal cells, contact inhibition, and division of migrating and stationary basal cells

• When an injury extends to tissues deep to the epidermis, the repair process is more complex then epidermal healing, and scar formation results
• Inflammatory phase, blood clot unites the wound edges, epithelial cells migrate across the wound, vasodilation and increased permeability of blood vessels deliver phagocytes, and fibroblasts form
• Migratory phase, epithelial cells beneath the scab bridge the wound, fibroblasts begin to synthesize scar tissue, and damaged blood vessels being to grow. During this phase, tissue filling the wound is called granulation tissue
• Proliferative phase, the events of the migratory phase intensify
• Maturation phase, the scab sloughs off, the epidermis is restored to normal thickness, collagen fibers become more organized, fibroblasts begin to disappear, and blood vessels are restored to normal

Homeostasis of body temperature

37oC (98.6oF)

Skin receptors sense the stimulus (heat) and generate impulses (input) that are transmitted to the brain (control center). The brain then sends impulses (output) to sweat glands (effectors) to produce perspiration. As the perspiration evaporates, the skin is cooled and body temperature returns to normal

Negative feedback mechanism

Adjusting blood flow to the skin

Do not occur until and individual reaches the late forties

Wrinkling, slower growth of hair and nails, dryness and cracking due to sebaceous gland atrophy, decrease in number of melanocytes (gray hair, blotching) and Langerhans cells (decreased immune responsiveness) and loss of subcutaneous fat (thinner skin)

Accelerates skin aging and greatly increases skin cancer risk

Ectoderm

Wandering mesenchymal cells

Burn

The local effects

First-degree and second-degree and third-degree burns

Partial thickness

Full-thickness

Determined by its depth, extent, and area involved, as well as the person's age and general health.

Burn area exceeds 70%

• The rule of nines (based on body surface)
• The Lund-Browder (based on age) method

Injury to the skin as a result of acute overexposure to the UV rays in sunlight

Caused by excessive exposure to sunlight

• Basal cell carcinoma (BCC)
• Squamous cell carcinoma (SCC)
• Malignant melanoma

• Skin type
• Sun exposure
• Family history
• Age
• Immunologic status

Inflammation of sebaceous glands that usually begin at puberty under the influence of androgens

Also known as, decubitus ulcers are caused by a constant deficiency of blood tissue overlying a bony projection that has been subjected to prolonged pressure against an object such as a bed, cast, or splint; the deficiency results in tissue ulceration