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