Post on 11-Jul-2020
The Integumentary System
Chapter 6
What is the integumentary system?
• skin
• hair
• nails
• glands
• blood vessels
• sensory receptors
What is your skin made of?
• 3 layers
• epidermis (outside)
• dermis (middle)
• subcutaneous layer (inside)
What is the epidermis?• outer layer of the skin, composed of 5 strata
(layers)
• stratum corneum - contains cells hardened with keratin for protection
• stratum lucidum - additional layer found only on palms of hands and soles of feet, provides additional thickness
• stratum granulosum - contains cells that secrete keratin
• stratum spinosum - contains cells that produce keratin
• stratum basale (basal cell layer) - contains epidermal stem cells that divide and migrate to the upper layers
What is in the dermis?
• middle layer of the skin
• made of loose connective tissue
• contains many small structures that help the skin function
• What structures are in the dermis?
• hair follicles - helps with sensing touch, insulation and protection
• arrector pili muscles - make the hairs stand up
• sweat glands - 2 types
• apocrine glands - secrete sweat into hair follicles, responsible for body odor
• eccrine glands - secrete sweat onto surface of skin, help to cool you down
• sebaceous gland - produce oil to keep hair flexible
• sensory receptors - nerves that sense touch, temperature and pain
• blood vessels - provide oxygen to skin cells
What is the subcutaneous layer?
• connects the dermis to muscle
• contains connective tissue, fat, nerves and blood vessels
What does your integumentary system do for you?
• Hair
• approximately 2.5 million hairs on the body
• found everywhere except palms of hands, soles of feet and lips
• develops from old, dead cells
• muscle and nerve connected to each hair
• hair provides sense, protection and insulation
• Nails
• protects the tips of fingers and toes
• contain keratin, which provides strength
• Can reflect health problems:
• bluish nails: circulatory problems
• white nails: anemia
• ridges or grooves: malnutrition
• red streaks: rheumatoid arthritis, high blood pressure
• clubbing: heart, lung, liver problems
• temperature regulation
• body heat is produced by muscle and liver cells
• skin helps keep the heat in
• body temperature is controlled by a part of the brain called the hypothalamus
• if body temperature gets too low, develop hypothermia
• cause mental confusion, loss of reflexes, shutting down of organs
• If body temperature gets too high, develop hyperthermia
• cause light headedness, dizziness, fatigue, nausea
How does your skin repair itself?
• laceration - a cut
• a cut into the epidermis will heal quickly
• a cut into the dermis will bleed, clot and take longer to heal
• a cut into the subcutaneous layer may require stitches or gluing
• 3 categories of burns
• first degree - only the epidermis is affected
• second degree - epidermis and part of the dermis is affected
• fluid develops between the two layers and blisters form
• third degree - damages all layers of the skin
• new cell growth is not possible
• requires a skin substitute to cover the skin and help with healing
What are common skin problems?
• Acne
• pimples for when glands become clogged
• can be hereditary
• most common cause is hormones
• Eczema
• severely dry skin
• can be hereditary or caused by allergic reaction
• requires moisturizing the skin and corticosteroids
• Sebhorreic dermatitis
• causes waxy, oily patches on the scalp
• common in infants, known as cradle cap
• can also appear in teens
• Skin cancer
• most common type of cancer in the US
• 3 types
• basal cell carcinoma
• squamous cell carcinoma
• melanoma - most deadly
• Psoriasis
• chronic disease that leads to the build up of excess skin tissue
• causes skin to appear red and be covered in silvery scales
What is a tattoo?
• permanent marking on the skin
• involves injecting ink into the dermis
• originated over 5000 years ago
• purpose varies with culture
What are the risks?
• allergic reactions to dyes
• skin infections (bacterial)
• bloodborne disorders (HIV, hepatitis, syphilis)
How are tattoos removed?
• excision - the tattoo is cut out and skin sewn back together
• skin graft - large tattoo is cut out and replace with skin from somewhere else
• laser - breaks tattoo ink into small particles, immune system removes them