Integumentary System (Skin) - San Dieguito Union High...
Transcript of Integumentary System (Skin) - San Dieguito Union High...
Learning Objectives
• Identify the major components
(anatomy) of skin
• Differentiate between the two types of
skin glands
• Explain the six functions (physiology) of skin
• Correctly name three abnormal skin colors and
identify causes
• Describe most common skin eruptions
• Describe the main diseases of the integumentary
system (pathophysiology)2
Skin Anatomy
• Largest Organ
• Three Main Layers
• Epidermis
– Outermost layer
– Cells constantly shed/replaced
• Dermis
– “true skin”
– framework of elastic connective tissue
– contains blood vessels, nerves, glands, hair follicles
• Hypodermis (subcutaneous fascia)
– connects to underlying muscles
– elastic and connective, fatty tissue3
Two Types of Glands
• Sudoriferous Glands
– sweat glands
– coiled tubes in dermis
– open on surface of skin at pores
• Sebaceous Glands
– oil glands that open onto hair follicles
– produce sebum (oil that keeps skin and hair from
becoming dry and brittle)
– sebum is antibacterial and antifungal
– when an oil gland becomes plugged, accumulation
of dirt and oil result in pimple4
Hair and Nails
• Hair
– consists of a root that grows in a
hollow tube called a follicle
– helps protect the body
– covers all body surfaces except for
palms and soles
– alopecia (baldness/genetic hair loss)
• Nails
– protect fingers and toes from injury
– made of dead, keratinized epidermal epithelial cells
– cells are packed closely together to form thick surface
– if lost, nails will regrow if the nail bed is not damaged5
Skin Physiology (Functions)
• Protection
– barrier to UV rays
– protects against invasion of pathogens/germs
– holds moisture in
– prevents deeper tissues from drying out
• Sensory Perception
– nerves in skin help body respond to pain, pressure,
temperature, and touch sensations
• Body Temperature Regulation
– blood vessels help body keep/lose heat
– glands also help cool body through perspiration 7
Skin Physiology Continued
• Storage
– skin tissues store fat, sugar, water, vitamins, & salts
– adipose (fatty) tissue is a source of energy
• Absorption
– certain substances can be absorbed through skin
– transdermal medications for motion sickness, nicotine
• Excretion
– skin helps body eliminate salt &small amounts of
waste
– excess water and heat through perspiration
• Production
– vitamin D production (matures in liver)
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Pigmentation (Skin Color)• Basic skin color is determined by pigments in epidermis
• Melanin
– Brownish/black pigment
– Varying amounts lead to black, brown, or yellow skin tint
– absorbs UV light and tans the skin
– small, concentrated areas of melanin form freckles
• Carotene
– yellowish-red pigment
– also determines skin color
• Albino
– person missing color pigments
– skin has pinkish tint
– hair is pale yellow or white
– eyes lack pigment and are red in color9
Abnormal Skin Colors
• Erythema
– reddish color that can be caused by burns
– also caused by congestion of blood in vessels
• Jaundice
– yellow discoloration of skin
– can indicate bile in blood as result of liver or gallbladder
disease
– occurs along with diseases involving destruction of red blood
cells
• Cyanosis
– bluish discoloration of skin
– caused by insufficient oxygen
– can be associated with heart, lung, and circulatory problems
• Gray/Brown Discoloration
– can be caused by chronic poisoning 10
Skin Eruptions• Macules
– flat spots on skin, such as freckles
• Papules
– firm, raised area such as pimples
– also seen in some stages of chickenpox and syphilis
• Vesicles
– blisters (fluid-filled sacs) such as those seen in chickenpox
• Pustules
– pus-filled sacs such as those seen in acne
• Crusts
– areas of dried pub and blood
– commonly called “scabs”
• Wheals
– itchy, elevated areas with an irregular shape
– hives and insect bites
• Ulcer
– deep loss of skin surface that may extend into dermis (scars)11
Pathophysiology (Diseases)• Acne Vulgaris
– inflammation of sebaceous (oil) glands
• Athlete’s Foot
– contagious fungal infection usually affecting feet
• Skin Cancer
– basal cell carcinoma, squamous cell
carcinoma, and malignant melanoma
• Dermatitis
– inflammation of skin in response to irritating substance
• Eczema
– noncontagious, inflammatory reaction irritant
• Impetigo
– highly contagious skin infection caused by bacteria
• Psoriasis
– chronic, noncontagious, inherited disease; scaly
• Ringworm
– highly contagious fungal infection of skin/scalp 12