1. Body Organization

2. Levels of Organization
Section 7- 4
Muscle cells
muscle tissues
Organs
Organ systems
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3. These Organ Systems function together to maintain homeostasis – a stable internal environment

4. Figure 35-2 Human Organ Systems Part I
Section 35-1
Nervous System
Integumentary System
Skeletal System
Muscular System
Circulatory System

5. Figure 35-2 Human Organ Systems Part 2
Section 35-1
Respiratory System
Digestive System
Excretory System
Endocrine System
Reproductive System
Lymphatic System

6. 4 Main Types of Tissues
1. Epithelial Tissue – cells pack tightly together and cover and protect underlying tissue; Lines our organs; Ex: stomach lining & skin

7. 4 Main Types of Tissues
2. Connective Tissue joins, supports, protects, and nourishes organs; Ex: ligaments, tendons, cartilage, bone, blood

8. 4 Main Types of Tissues
3. Muscle Tissue – contracts and relaxes for movement
Skeletal muscle- moves bone; voluntary (works when you want it to)
Cardiac Muscle-Only found in the heart. Involuntary (works all the time)
Smooth Muscle-involuntary (works all the time)

9. 4 Main Types of Tissues
4. Nervous Tissue – sends electrical signals throughout the body. Ex: Brain, Spinal Cord, Nerves

11. Integumentary System

12. Functions of the Skin Covers and protects the body
What does the skin protect us from?
Pathogens
Injury
Ultra-violet radiation
Body’s Museum in Atlanta

13. Functions How does it regulate temperature?
2. Regulate body temperature/reduces water loss
How does it regulate temperature?
Sweating
Dilate/constrict of blood vessels
Goose bumps

14. Functions 3. Excretes Waste like Urea How are wastes excreted?
In sweat
subcutaneous

15. Functions
4. Sensory receptors input information to the brain about the outside environment
Chemo
Mechano
Chemo
Photo
Mechano

16. There are 2 main layers of skin
outer layer
deeper layers

17. Epidermis Outer (surface) layers of skin Two Parts:
Dead
keratinocytes
Lamellar granules
Keratinocyte
Langerhans cell
Melanocyte
Merkel cell
Tactile disc
Sensory neuron
Stratum
corneum
lucidum
granulosum
spinosum
basale
Dermis
Outer (surface) layers of skin
10-30 cells thick
Two Parts:
Inner part composed of living cells
Outer part is of dead cells

18. Dermis Deeper layers of skin 10-20 times thicker than epidermis.
Top layer arranged
In ridges.
Dermis

19. Specialized Cells of the Epidermis
Melanocytes are cells that produce melanin.
Melanin is a pigment that helps to protect the skin from harmful ultraviolet solar radiation from the sun.
Makes your skin darker or lighter

20. Interesting Tidbit NO! Melanocytes Do some people have
more melanocytes
than other people?
NO!

21. Interesting Tidbit Melanocyte
Skin pigmentation is due to the type and amount of melanin produced
Eumelanin produces darker pigments
Phaeomelanin produces lighter pigments and freckles
These often occur together in varying amounts
Melanocyte

22. Interesting Tidbit Ridges help the epidermis bind to the dermis.
The uneven ridges
create fingerprints
Dermis

23. Accessory Organs of the Dermis
1. Hair follicles – tube-like depression where the hair develops

24. Accessory Organs of the Dermis
2. Sebaceous glands – secret oily sebum to soften and waterproof skin

25. Accessory Organs of the Dermis
3. Nails – protective covers of ends of fingers and toes.

26. Accessory Organs of the Dermis
4. Sweat glands:
secrete waste
regulate heat

27. Accessory Organs of the Dermis
5. Blood vessels – to nourish skin cells

28. Accessory Organs of the Dermis
6. Nerves – to send and receive messages
Subcutaneous

29. Accessory Organs of the Dermis
7. Erector pilli muscle
-smooth muscle
-causes
“goosebumps”
hair to
stand erect
subcutaneous

30. Subcutaneous layer Anchors dermis to the body Contains fat cells to
protect
and cushion
Subcutaneous layer

31. Self Quiz
What are the three layers of skin?

32. Self Quiz

33. Self Quiz

34. Self Quiz

35. Self Quiz

36. Self Quiz

37. Self Quiz

38. Self Quiz

39. Self Quiz

40. Self Quiz

41. Self Quiz

42. Self Quiz

43. Interesting Tidbits
A fingernail or toenail takes about 6 months to grow from base to tip
Fingernails grow faster than toenails
An average human scalp has 100,000 hairs
We lose between 40 and 100 hairs per day
Blondes have more hair than brunettes

44. Interesting Tidbits
Friction of the epidermis causes cell division to increase.
This outward thickening is called a callous.
Sometimes growth is inward, creating a corn.
Humans shed about 600,000 particles of skin per hour – about 1.5 pounds per year.
At age 70, you will have lost about 105 lbs of skin.

45. Interesting Tidbits Fingerprints provide traction for grasping objects
Even identical twins have different fingerprints
Every square inch of dermis contains twenty feet of blood vessels
Skin on our hands and feet is thicker. When we bathe, skin takes on water and swells slightly.
In the thicker areas, increased surface area creates crowding. The skin must wrinkle to accommodate the changes

46. Interesting Tidbits
Your body is composed of approximately 100 Trillion cells
About 16% of your body weight is skin
The skin is completely renewed every 27 days
You will make almost 1000 new skins in a lifetime
If all the layers of your skin were laid out on the ground, it would cover about 20 m2 or 2 parking spaces

47. Disorders of the Skin
1. Acne – infection of sebaceous gland

48. Disorders of the Skin
2. Vascular Birthmarks – Blood vessel abnormality affecting .5% of population – darkens skin

49. Disorders of the Skin
3. Dermatitis – dry, sensitive skin

50. Disorders of the Skin
4. Fungal infections
Ring Worm
Athlete’s Foot

51. Disorders of the Skin
5. Impetigo – bacterial infection

52. Disorders of the Skin
6. Psoriasis – chronic inflammation

53. Disorders of the Skin
Melanoma
7. Cancer
Carcinoma

54. Disorders of the Skin
8. Warts- viral infection

55. Disorders of the Skin
9. Burns
First degree
Second degree
Third degree

56. Concept Map Skin Section 36-3 functions as a is made up of the
Barrier to infection
Regulator of body temperature
Remover of waste products
Protector against UV radiation
Epidermis
Dermis
which is the
which is the
Outer layer
Inner layer

57. Albanism: a defect of melanin production that results in little or no color (pigment) in the skin, hair, and eyes.

58. Albanism is a genetic disorder that is carried on the recessive allele.