Integumentary%20System

1
Integumentary System
2

• Sites used http//www.meddean.luc.edu/lumen/MedEd/
  medicine/dermatology/melton/skinlsn/sknlsn.htm
• http//www.lab.anhb.uwa.edu.au/mb140/CorePages/Int
  egumentary/Integum.htm

3
Skin

• 9 lbs. (4.1 kgs)
• Covers S.A. of 15-20 ft2 (1.4 to 1.9 m2)
• Every square inch contains 15 blood vessels,
  12 nerves, 650 sweat glands, 100 oil glands,
  1500 sensory receptors, 3 million cells
• Thickness varies from 1/32 to 1/8
• Skin cells die replaced continuously
• 3 layers epidermis, dermis hypodermis

4
Skin-Major Functions

• Protects
• Excretion/Secretion
• Helps regulate body temperature
• Sensation (Cutaneous sensation)
• Promotes vitamin D synthesis
• Acts as reservoir for blood

5
Protects

• 3 ways
• Chemically
• Physically
• Biologically

6
Protects-Chemically

• Acidic skin secretions inhibit bacteria from
  multiplying
• Substances in sebum (oil) kill some bacteria
• Melanin-shield skin from UV rays

7
Protects-Physically

• Keratinized cells-ex.epidermis, hair and nails
• Barrier to invading organisms

8
Protects-Biologically

• Dermal macrophages-2ndline of defense against
  bacteria
• Epidermis contains macrophage like Langerhans
  cells immunity

9
Excrete/Secrete

• Sweat-nitrogenous waste, sodium chloride
• Sebum-secreted by sebaceous glands

10
Regulate Body Temp.

• Evaporation of sweat
• Dermal blood vessels dilate and constrict

11
Cutaneous Sensation

• Sensory receptors-Meissners, Pacinian,
  Ruffinis, Krauses, free nerve endings

12
Vitamin D Synthesis.

• Exposed to UV-skin converts cholesteral molecules
  to Vitamin D

13
Reservoir for blood

• Shunted from skin to general circulation ex. To
  working muscles

14
Skin

• 3 layers
• Epidermis
• Dermis
• Hypodermis

15
1. Epidermis

• Most superficial layer of skin
• First barrier of protection
• Principle (main) cell type in epidermis
  keratinocytes
• 4-5 layers
• 4 types of epidermal cells

16
2. Dermis

• Contains sebaceous and sweat glands
• Sensors
• 2-A) Pacinian corpuscle heavy touch
  vibratiions
• 2-B) Meissners corpuscle light touch

17
3. Hypodermis

• Most of the blood flow (arteries veins)
• Contains fat for insulation cushioning

18
4. Hairs

• Protection
• Decrease heat loss
• Errector pilius pulls hair errect during stress

19
Common Disorders

1. Eczema
2. Psoriasis
3. Freckles/Moles
4. Atheletes Foot/Jock Itch
5. Melanoma

1. Calluses/Corns
2. Bruising
3. Impetigo

20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
(No Transcript)
24
(No Transcript)
25
(No Transcript)
26
(No Transcript)
27
(No Transcript)
28
Epidermal Cells

• Keratinocytes compose most of epidermis make
  protein keratin
• Keratin waterproofs and protects skin
• Melanocytessynthesize melanin
• Melanin protects against UV damage
• Merkel cells associated with sensory receptors
  (touch)
• Langerhans cells macrophages used in defense
  against microorganisms

29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
(No Transcript)
43
(No Transcript)
44
(No Transcript)
45
(No Transcript)
46
(No Transcript)
47
(No Transcript)
48
(No Transcript)
49
(No Transcript)
50
(No Transcript)
51
(No Transcript)
52
(No Transcript)
53
(No Transcript)
54
(No Transcript)
55
(No Transcript)
56
(No Transcript)
57
(No Transcript)
58
(No Transcript)