1. The Integumentary System
Health Science I

2. INTEGUMENTARY SYSTEM Skin = Integument = Cutaneous Membrane
7 Functions:
Protective covering
2. Regulates body temperature
3. Manufactures Vitamin D
4. Sensory function
5. Temporary storage of fat, glucose, water and salts
6. Screens out harmful ultraviolet radiation
7. Absorbs topical drugs
Skin is called integument. It is a cutaneous membrane. There are two basic layers of the skin and together they are called of our skin is called the integumentary system.
Our integumentary system has seven primary functions: protection, regulation of body temperature, manufacturing of Vitamin D, sensory properties, temporary storage of fat, glucose, water and slats, blocking of UV radiation, and absorption.

3. STRUCTURE OF THE SKIN 2 basic layers Epidermis Dermis
Outermost covering
Epithelial cells
Avascular
Dermis
True skin
Connective tissue
Vascular
As stated before, there are two layers of the skin. The epidermis and dermis. The epidermis is the outer most layer...it is what we see. The epidermis is made up of epithelial cells and is avascular. This means that it does not have a blood supply. Have you ever stuck a pin through a thin layer of your skin so it looks like it is hanging from your finger? You did not bleed because you had only penetrated the epidermis.
If you had pushed the pin a little deeper then you would have bled because you would have penetrated the dermis. Just under the epidermis is the second layer called the dermis. It is also called our “true skin”. There are many things in this layer like blood vessels, connective tissue, nerve endings, muscles, hair follicles, oil and sweat glands and fat cells.

4. EPIDERMIS 5 epidermal layers are: Stratum corneum Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum germinativum
(superficial to deep)
Even though the epidermis is thin it has five distinct layers. From superficial (closest to the outside) to deepest (innermost) they are stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and the stratum germinativum (nicknamed stratum “g”).

5. STRATUM CORNEUM (most superficial)
Outermost layer
In cells, cytoplasm replaced by KERATIN – making them waterproof.
Flat and scale-like cells that flake off
First line of defense against surface bacteria
Thickest on palms of hands, soles of feet

6. STRATUM LUCIDUM
Found only on the palms of hand and soles of feet. Cells here appear clear.

7. Stratum Lucidum

8. STRATUM GRANULOSUM
Keratinization process begins and cells begin to die.
Keratinocytes(predominant cell in epidermis) change their shape, lose their nucleus, lose most of their water, and become mainly hard protein or keratin.

9. Granulating Wound

10. Granulating Wound
Granulation tissue is new connective tissue and tiny blood vessels that form on the surface of a wound during the healing process. Granulation tissue typically grows from the base of a wound and is able to fill wounds of almost any size

11. Stratum Spinosum Melanocytes, keratinocytes and Langerhans cells
These cells look prickly under microscope
One of main functions is keratinization(old cells moving up toward surface and leaving)

12. STRATUM GERMINATIVUM (deepest)
Innermost epidermal layer
Reproductive layer – cells form and push their way up, become keratinized, and replace the top layer
Contains MELANOCYTES – cells that contain a pigment = MELANIN
The stratum g is special because it is the reproductive layer of the epidermis. As cells form in the stratum g they push their way up towards the stratum corneum. During this ascent they become keratinized. Keratin is a structural protein that makes epithelial cells strong, tough, and almost water proof.
The stratum g also contains cells called melanocytes. Melanocytes contain a pigment called melanin. Melanin is what gives color to our skin

13. Melanocytes Make protein melanin
Melanin protects the skin against the ultraviolet rays of the sun

14. MELANIN  Black, brown, or has a yellow tint –
depending on racial origin
 The more melanin, the darker the
skin
 Caucasians don’t have much melanin
in their melanocytes.
 Albinism = no melanin
 Freckles = patches of melanin
Melanin appears as black, brown, or with a yellow tint. The more melanin you have the darker your skin is. Caucasions do not have a lot of melanin while African Americans have a large amount. Someone without any melanin whatsoever has a disorder called albinism.
What is a freckle? A freckle is a cluster of melanin.

15. TANNING Sunlight stimulates melanocytes to make more melanin
“Tanning” produced by UV rays.
Prolonged exposure may lead to skin cancer!
So, how do we get darker? How do we get a tan? Sunlight stimulates melanocytes to create more melanin. UV rays stimulate this creation of melanin. The more exposure to the sun the darker you become. However, you must be aware that prolonged exposure to the sun will cause skin cancer!

16. PAPILLAE Ridges in stratum germinativum that arise from dermis
Create permanent ridges in fingers, palms and soles of feet
These “friction ridges” help with grip
Cause “fingerprints”
What else is in the stratum g? There are ridges in the stratum g that arise from the dermis. The ridges, called papillae, cause ridges in finger tips, on our palms, and on the soles of our feet. These ridges help with grip and are called fingerprints.

17. PAPILLAE

18. DERMIS Connective tissue Blood vessels Nerve endings Muscles
Thicker inner layer that contains:
       Connective tissue
       Blood vessels
       Nerve endings
       Muscles
       Hair follicles
       Oil and sweat glands
Fat cells
The second layer of the skin, the “true skin” contains:
Connective tissue
       Blood vessels
       Nerve endings
       Muscles
       Hair follicles
       Oil and sweat glands
Fat cells

19. DERMIS

20. NERVE RECEPTORS IN DERMIS
·Sensory nerves – heat, cold, touch, pain and pressure
·Touch receptors close to the surface
·Pressure receptors are deeper
The nerves in the dermis include sensory nerves that sense heat, cold, touch, pain, and pressure. Near the surface of the dermis are touch receptors while pressure receptors are deeper in the dermis.

21. SUBCUTANEOUS LAYER ·Innnermost layer
Lies under the dermis (not really part of integumentary system)
·Made up of loose connective tissue
Contains half of the body’s stored fat
Below the dermis is the subcutaneous layer. This layer is not technically part of the integumentary system. It is made up of loose connective tissue and it contains half of the body’s stored fat.

22. Subcutaneous
Attaches the integumentary system to the surface muscles underneath

23. SUBCUTANEOUS LAYER
With age, the subcutaneous layer begins to disappearcausing skin to wrinkle and sag.

24. Functions of the integumentary system
The skin has remarkable ability to heal itself. How does this happen?
3.06: Understand the functions and disorders of the integumentary system

25. APPENDAGES OF THE SKIN Hair Nails Glands Sweat glands
Sebacceous glands

26. APPENDAGES OF THE SKIN HAIR Outer layer = CORTEX Inner layer = MEDULLA
Almost everywhere on the body
Length, thickness, type and color varies
Outer layer = CORTEX
Inner layer = MEDULLA
Part under the skin = ROOT
Part outside the skin = SHAFT
FOLLICLE = pocket through epidermis into dermis, hair inside…originates in dermis
PAPILLA = tuft of tissue at base of root, contains capillaries
An appendage of the skin that is rooted in the dermis is our hair. Our body is almost entirely covered by hair. The outer layer of a strand of hair is called the cortex and the inner layer is called the medulla. The part of the hair that is in the dermis is called the root while the part that we see, the part outside the skin is called the shaft.
Each strand of hair sits in a pocket called a follicle. The follicle goes through the epidermis into the dermis.
At the base of the root is a tuft of tissue which contains capillaries…blood supply for the hair appendage.

27. APPENDAGES OF THE SKIN CONT’D
ARRECTOR PILI MUSCLE = smooth muscle attached to follicle.
How does this muscle cause goose bumps?
NAILS
Nail is formed in the nail bed or MATRIX
Epidermal cells fused together and filled with keratin
Attached to each follicle are muscles called arrector pili muscles. These are smooth muscles the raise the shaft. Have you ever had “goose bumps”? They are caused by the contraction of the arrector pili muscles.
Our nails are also considered appendages of the skin. They are formed in the nail bed or nail matrix. Nails are epidermal cells that are fused together and fill with keratin (structural protein that makes cells strong and nearly water proof).

28. SWEAT GLANDS ·Perspiration is 99% water
·SUDORIFEROUS GLANDS produce sweat
Distributed over the entire skin surface
Large numbers where???
Duct extends to form a pore in the skin, perspiration excreted through the pores
May be activated by heat, pain, fever and nervousness
·Average fluid loss is 500 ml per day
The dermis also contains sudoriferous glands, or sweat glands. All over our body we have sudoriferous glands. There is a large number congregated under the arms, palms of hands, soles of feet, and on our forehead. A duct extends from the dermis through the epidermis to form a pore where sweat is excreted. Creation of perspiration (sweat) is activated by heat, pain, fever, and nervousness.
99% of sweat is water…we loose an average of 500ml a day from sweat….that is approximately 17 ounces or just over 2 cups!

29. SEBACEOUS GLANDS
Secrete oil (SEBUM) that protects and lubricates the skin
Sebaceous glands are similar to sudoriferous glands in that they originate in the dermis and go through the epidermis to form a pore on the surface of the skin to secrete sebum, or oil.
This oil protects and lubricates our skin.

30. SKIN AND MICRORGANISMS
Intact skin = best protection against pathogens, toxins and water loss
Skin generally too dry for microbial growth – usually grow in moist areas 
Most skin bacteria associated with hair follicles or sweat glands
Underarm perspiration odor caused by bacteria and perspiration

31. DISORDERS OF THE SKIN ACNE
Common and chronic disorder of sebaceous glands
Sebum plugs pores area fills with leukocytes
Also – blackheads, cysts, pimples and scarring

32. DISORDERS OF THE SKIN ATHLETE’S FOOT Contagious fungal infection
Usually contracted in public baths and showers…don’t share towels…wear shower shoes
Rx – anti-fungal agents

33. DISORDERS OF THE SKIN DERMATITIS
Non-specific inflammation of skin – contact with allergens
Can be a rash – reaction to soap, plants, etc.
Can be emotional – stress can cause skin blotches

34. DISORDERS OF THE SKIN GENITAL HERPES
Viral - blister in genital area… STD
Spread through sexual contact - Periods of remission and exacerbation
Rx – Acyclovir
Can be passed to newborn during vaginal delivery

35. DISORDERS OF THE SKIN SKIN CANCER
Associated with exposure to sun (UV rays)
Most common type of cancer in people

36. DISORDERS OF THE SKIN MALIGNANT MELANOMA (type of skin cancer)
Occurs in melanocytes
Metastasizes to other areas quickly
Appears as brown or black irregular patch that occurs suddenly
A change in an existing wart or mole may indicate melanoma
Rx – surgical removal of melanoma and surrounding area and chemotherapy

37. Warts Viral Skin lesions Can recur after removal Treatments include:
Topical medication
Oral medication
Surgery

38. Alopecia Normal hair is replaced by a very short, transparent hair.
All regular hair is
lost.

39. BURNS
Caused by radiation, sun, boiling water, chemicals, fire or electricity
RULE OF NINES – Measures percent of body burned. Body divided into 11 area, each is 9% of body surface.

40. FIRST DEGREE BURN Superficial Skin red and dry – no blisters
Involves only epidermis
Rx – cold water
Healing within one week (i.e. sunburn)

41. SECOND DEGREE BURN Epidermis and dermis
Pain, swelling, redness and blistering
Skin may be exposed to infection
Rx – pain medication, dry sterile dressing
Healing within 2 weeks

42. THIRD DEGREE BURN Epidermis, dermis and subcutaneous layers
Symptoms – loss of skin, blackened skin
May be life threatening

43. Decubitus Ulcers/Pressure Sores
Areas of damaged skin and tissue that develop when sustained pressure — usually from a bed or wheelchair
Circulation is cut off to vulnerable parts of your body, especially the skin on your buttocks, hips and heels.
Without adequate blood flow, the affected tissue dies.