1. Skin Hair Nails and associated glands
Integumentary System
Cutaneous = skin
Skin
Hair
Nails
and associated glands

2. Skin is the largest organ of the body 17,000 sq cm –average adult
Function:
Protection -prevent vs dehydration,microbes,UV radiation, physical insult
Regulate Temperature
Vitamin D synthesis
Information about environment – extension of the nervous system

3. Skin has 3 distinct sections
Epidermis = layers of stratified squamous epithelial tissue
Dermis = loose connective tissue
Hypodermis [subcutaneous] - adipose tissue

4. Subcutaneous tissue anchors skin to the underlying tissue/organs
1/2 of the body’s adipose tissue
‘storage adipose’ = energy adipose
also contributes to cushioning and temperature control
aging/maturation = distribution of fat stores changes
“baby fat” over whole body
male - neck, lower back ‘love handles’
female - breast,hips/thighs
abdomen

5. Epidermis
Epidermis – The outer most layer composed of epithelial cells. It is subdivided in to thin layers called strata and contains no blood vessels

6. Epidermis has 5 distinct layers of cells
stratum basale - one layer of cells
stratum spinosum layers of cells
stratum granulosum layers of cells
stratum lucidum - several layers of cells
stratum corneum layers of cells

7. Specialized cells in epidermis
Melanocytes - produce melanin - pigment--- 25% of basal cells
Keratinocytes - produce a protein mixture of keratin
Langerhans cells - phagocyte
Merkel’s cells - specialized cells associated with nerve endings -detect light touch and pressure
melanocyte

8. The stratum corneum is the outer most stratum of the epidermis.
It is comprised of flat, tough, keratin containing cells that provide a protective layer for the skin.
Keratin is a protein that strengthens the cells and is also found in other areas of the body.
The cells in this stratum are either dead or dying, as they have no blood vessels to keep them alive.

9. Stratum lucidum
Stratum granulosum
Stratum corneum

10. Highly pigmented skin
keratinocytes

11. Dermis
Also called the “true skin.”
Is a network of elastic connective tissue that contains blood vessels and nerves, as well as the appendages of the skin.
Extensions of the dermis, known as papillae, extend toward the epidermis and form what we know as fingerprints.

12. Dermis has two distinct regions
Papillary region: top area loose connective tissue with high % of elastin fibers
folds called dermal papillae - ridges for friction/gripping
fingerprints
Reticular region:connective tissue with collagen and elastin fibers stretch -return to original shape
Papillary region

13. Structures in Dermis Blood vessels hair follicles sebaceous glands
sweat glands [sudoriferous glands]
merocrine - help regulate temperature
eccrine - don’t regulate temperature -odor
arrector pili muscle
Nerve endings – pain, temperature, touch, vibration
other glands: ceruminous glands [modified merocrine]

14. Sweat Glands
The technical name for sweat glands is sudoriferous glands.
Sudoriferous glands help regulate body temperature through the evaporation of sweat.
Secretions of the sweat glands in the groin and armpits also contain cellular debris that produce body odor when broken down by bacteria.

15. Sebaceous Glands
Produce sebum, an oily substance that prevents drying of the skin and hair.
Blackheads are blocked sebaceous glands full of dried sebum and keratin.
Pimples are infected blackheads.
Sebaceous cysts may form over time if the glands stays blocked and will continue to increase in size. (until they’re dealt with)

16. Hair is composed primarily of keratin and covers most of the body.
The hair grows from the follicle, a sheath in the dermis.
Most follicles have a small muscle associated with it, which allows it to raise forming “goose bumps.”
Factoid: eye lashes protect eyes, but also sense when something is coming towards the eye. Grow new eyelashes every 5 weeks.

17. HAIR
shaft : part above skin surface
root: part below skin surface

19. Nails – extensions of the epidermis Protective & functional
The larger the digit, the faster the nail grows

20. Nails
Nails are made of hard, keratinized cells and provide protection to the fingers and toes.
New cells form continuously in the nail root at the proximal end of the nail.

22. Pigment
The color of the skin is controlled by the amount of melanin in the skin.
As melanin helps protect the skin from UV rays, the amount of melanin increases with sun exposure.
Discolorations
Pallor – often decreased blood flow or anemia.
Flushing – increased blood flow, often related to exercise,fever, or infection.
Cyanosis – blueing of the skin due to decreased oxygenation of the blood.

23. Jaundice – yellowing of the skin from increased bilirubin in the blood often associated with liver disease and hemolytic disease.
Carotenemia – excessive intake of carotene containing vegetables, like carrots, leading to an orange cast to the skin.
Bronzing/ gray/ brown discolorations – Addison’s disease, chronic poisonings

24. Lesions are essentially any damage to tissue.
Size, shape, height, and/or depth of the lesion are all important aspects in evaluating a skin lesion.
Surface Lesions
Rash – an area of erythema (redness) of the skin.
Eruption – a raised rash, often erythematous.
Macules – flat spots, such as in measles and freckles.

25. Papules – firm, raised areas, such as in chickenpox or pimples
Surface Lesions
Papules – firm, raised areas, such as in chickenpox or pimples
Nodules – Large papules
Vesicles – blisters full of fluid, such as in poison ivy
Pustules – infected vesicles filled with pus, such as in folliculitis
Papules from scabies

26. Nodule from Basal Cell Carcinoma of Scalp

27. Herpes simplex induced vesicles

28. Pustules induced by a Group A beta-hemolytic streptococcal infection

29. Laceration – a rough, jagged wound from tearing, more than cutting
Deeper Lesions
Excoriation – scratches, often associated with intense itching or a psychological disturbance
Laceration – a rough, jagged wound from tearing, more than cutting
Ulcer – from death of tissue, such as with diabetic and tropical ulcers
Fissure – a crack in the skin, such as in athlete’s foot.
Excoriations from Swimmer’s Itch

30. Fissure

31. Effects of Aging on the Integumentary System
Thinning of the dermis
Decreased elasticity
Wrinkling due to decreased collagen and fat
Thinning, drying, whitening of the hair – by 50 yrs of age, most people will start ‘graying’
Decreased perspiration
Nail growth slows
Decreased blood flow will upset temperature regulation

32. Common Terms to be familiar with
Dermatosis and Dermatitis
Dermatosis is any skin disorder.
Dermatitis is an inflammation of the skin which can have a large variety of causes.

33. Contact Dermatitis from metal

34. Contact Dermatitis from Adhesive

35. Alopecia is the technical term for baldness
Aside from hereditary male pattern baldness, alopecia can be caused by:
Malnutrition
Chemotherapy
Systemic disease
It can also be idiopathic
Approx. 50%of male population will have some degree of balding with increased age

36. B D Tyagi of Bhopal in India The hair growing from the middle of his ears measures an astonishing 10.2cm at its longest point, which is probably long enough for small pony tails.