1. Do Now
Read the article about cellulite and answer the questions.

2. Finish Lab Get with your partner from yesterday to finish your lab.
You will do the fourth activity of the lab.
Follow the directions to experiment with temperature receptors in the skin.

3. DO NOW Hand in your skin sensitivity lab.
What conclusions did you make from this lab?

4. Objectives To explain the function of the integumentary system.
To identify the components of the epidermis.
To list the strata of the epidermis.

5. The Integumentary System: An Overview

6. Functions: Protective covering Helps regulate body temperature
Retards water loss from deeper tissues
Houses sensory receptors
Synthesizes biochemicals
Excretes small quantities of waste

7. Consists of… Cutaneous membrane
Epidermis
Dermis
Accessory structures- hair, sweat glands, sebaceous glands etc.
Subcutaneous layer (hypodermis)

8. Components
Figure 5.1

9. The Epidermis

10. Thin Skin and Thick Skin
The epidermis is composed of layers of keratinocytes- cells that produce keratin
Thin skin = four layers (strata)
Thick skin = five layers
Figure 5.2

11. The Epidermis Composed of stratified squamous epithelium
Lacks blood vessels
Older cells are pushed to the top and harden in a process called keratinization.

12. Layers of the epidermis:
From deep…….
Stratum basale/ germinativum
Stratum spinosum
Stratum granulosum
Stratum lucidum
Stratum corneum
…… to superficial

13. The Structure of the Epidermis
Figure 5.4

14. Epidermis Cell Layers Germinative Spinosum- spiny layer
Basal cells (stem) are reproducing
Spinosum- spiny layer
Granulosum- grainy layer
Stops dividing, start producing keratin
Lucidum
The clear layer found only in thick skin
Corneum
Exposed to surface and shed every 2 wks.

15. Skin color depends on… Blood supply Carotene Melanin
Interrupted blood supply leads to cyanosis- blue!
Carotene
Orange-yellow pigment found in orange vegetables
Melanin
Yellow-brown pigment
Protects us from UV radiation
Produced by melanocytes

16. Melanocytes
Figure 5.5a, b

17. Epidermal cells
Synthesize vitamin D3 (cholecalciferol) when exposed to UV
Aids in absorption of calcium and phosphorus- needed for bone strength
Respond to epidermal growth factor
Growth
Division
Repair
Secretion

18. Skin Cancer

19. Lab
Begin working on the “Integumentary System” lab. Do as much as you can in the rest of the period. The slides will be posted on the powerpoint for clarity.

20. Do Now
Read the article “Whats the skinny on tattoos” on my desk and answer the questions.

21. Objectives The explain the components of the dermis.
To understand why tattoos are permanent.
To identify accessory organs of the integument and explain their function.

22. The Dermis

23. Dermal Organization Located between epidermis and subcutaneous layer
Anchors accessory structures- hair follicles, sweat glands, blood vessels etc.
Two components:
Outer papillary layer
Deep reticular layer

24. Layers of the Dermis Papillary layer Reticular layer Areolar tissue
Contains blood vessels, lymphatics, sensory nerves of epidermis
Reticular layer
Dense irregular connetive tissue
Contains network of collagen and elastic fibers to resist tension

26. Dermal Circulation
Figure 5.8

27. Stretch Marks Caused by excessive stretching of the dermis
Patterns of collagen and elastic fibers form lines of cleavage

28. Lines of Cleavage of the Skin
Figure 5.7

29. Hypodermis Elastic areolar tissue and adipose tissue
Stabilizes skins position against underlying organs and tissues
Shock absorber and insulator
Few capillaries and no vital organs
Subcutaneous injection is useful to administer drugs

30. Hairs
Composed of keratinized dead cells that are produced in hair follicles
Project deep into the dermis and often into the hypodermis

31. Structures Hair papilla Root Shaft
Connective tissue containing capillaries and nerves
Root
Anchors hair into skin
Shaft
Part we see on the surface
Consists of three layers
Cuticle- overlapping shingle layer
Cortex- underlying layer- pigments
Medulla- core of hair

32. Structures Contd. Sebaceous Glands Arrector pili muscle
Discharge oily substance into hair follicles
Inhibits growth of bacteria
Arrector pili muscle
Pulls on follicle, forcing the hair to stand up
Cold or emotional states- goosebumps

33. Anatomy of a Single Hair
Figure 5.9

34. Hair Follicles and Hair

35. Hair Follicles
Figure 5.10a-c

36. Hair Color
Produced by melanocytes at the hair papilla

37. Function of Hair Head Nostrils, ears, and eyes Sensory
Protection from UV light
Cushion a light blow to head
Insulation
Nostrils, ears, and eyes
Prevent entry of particles
Sensory
Sensory nerve fiber at base of every hair

38. Exocrine Glands- Reach Outside
Sebaceous glands (Oil glands)
Associated with hair
Secrete sebum, which lubricates and inhibits bacteria growth
Acne- condition when they are clogged
Sweat glands (Watery Glands)
2 kinds
1- hormonal- armpits, groin, nipples
2- All over body

39. Sebaceous Glands and Hair
Figure 5.11

40. Sweat Glands

41. Figure Sweat Glands
Figure 5.12a, b

42. Nails
Keratinized cells that protects the tips of fingers and toes

43. Structures Nail Body Nail Root Cuticle
Covers an area of the epidermis called the nail bed
Nail Root
Where nail production occurs
Not visible on surface
Cuticle
Portion of stratum corneum

44. Structure Contd. Lunula
Pale crescent area near the root were blood vessels are absent

45. Figure 5.13 The Structure of a Nail

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The Skeletal System
The Skeletal System
provides structural support
The Integumentary System synthesizes vitamin D3, essential for calcium and phosphorus absorption (bone maintenance and growth)
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The Muscular System
The Muscular System’s facial muscles pull against skin of face, producing expressions important in communication
The Integumentary System synthesizes vitamin D3 , essential for normal calcium absorption (calcium ions play an essential role in muscle contraction)
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The Nervous System
The Nervous System controls blood flow and sweat gland activity for thermoregulation; stimulates contraction of arrector pili muscles to elevate hairs
The Intergumentary System’s receptors in dermis and deep epidermis provide sensations of touch, pressure, vibration, temperature, and pain
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The Endocrine System
The Endocrine System includes the sex hormones that stimulate sebaceous and apocrine gland activity, and develop secondary sexual characteristics; suprarenal hormones alter blood flow to skin and mobilize lipids from fat cells
The Integumentary System synthesizes vitamin D3, precursor of calcitriol, a hormone produced by the kidneys
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53. The Cardiovascular System
The Cardiovascular System provides oxygen and nutrients; delivers hormones and cells of immune system; carries away carbon dioxide, waste products, and toxins; provides heat to maintain normal skin temperature
The Integumentary System’s mast cells produce localized changes in blood flow and capillary permeability
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The Lymphatic System
The Lymphoid System assists in defending the integument by providing additional macrophages and mobilizing lymphocytes
The Integumentary System provides physical barriers that prevent pathogen entry; macrophages resist infection; mast cells trigger inflammation and initiate the immune reponse
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55. The Respiratory System
The Respiratory System provides oxygen and eliminates carbon dioxide
The Integumentary System’s hairs guard entrance to nasal cavity
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The Digestive System
The Digestive System Provides nutrients for all cells and lipids for storage by adipocytes
The Integumentary System synthesizes vitamin D3, needed for absorption of calcium and phosphorus
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The Urinary System
The Urinary System excretes waste products, maintains normal body fluid pH and ion composition
The Integumentary System assists in elimination of water and solutes; keratinized epidermis limits fluid loss through skin
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58. The Reproductive System
The Reproductive System’s sex hormones affect hair distribution, adipose tissue distribution in subcutaneous layer, and mammary gland development
The Integumentary System covers external genitalia; provides sensations that stimulate sexual behaviors; mammary gland secretions provide nourishment for newborn infant
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