1. The Integumentary System
Chapter 5
The Integumentary System
Part A

2. Functions Protection – Barrier against infection and injury
Help regulate body temperature
Removes waste
Protects against UV radiation
Sensation -- touch
Produce vitamin D
Reservoir of blood

3. Skin (Integument)- largest organ
Consists of three major regions
Epidermis – outermost superficial region
Dermis – middle region contains nerves, bloods vessels and glands
Hypodermis – deepest region, contains fat

4. Skin (Integument) Figure 5.3 Figure 5.3
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5. Cells of the Epidermis
Keratinocytes – produce the fibrous protein keratin
Melanocytes – produce the brown pigment melanin
Langerhans’ cells – epidermal macrophages that help activate the immune system
Merkel cells – function as touch receptors in association with sensory nerve endings

6. Sweat Glands
2 types prevent overheating of the body; others secret cerumen and milk
Eccrine sweat glands – found in palms, soles of the feet, and forehead
Apocrine sweat glands – found in axillary and anogenital areas
Ceruminous glands – modified apocrine glands in external ear canal and secrete cerumen
Mammary glands – specialized sweat glands that secret milk
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

7. Skin Color Three pigments contribute to skin color
Melanin – yellow to reddish-brown to black pigment, responsible for dark skin colors
Protects skin from damage by absorbing UV radiation
Freckles and pigmented moles – result from local accumulations of melanin
Carotene – yellow to orange pigment, most obvious in the palms and soles of the feet
Hemoglobin – reddish pigment responsible for the pinkish hue of the skin
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

9. Sebaceous Glands Soften skin Found all over the body
Secrete an oily secretion called sebum
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

10. Hair
Helps maintain warmth, senses insects on the skin, and guards the scalp against physical trauma, heat loss, and sunlight
Filamentous strands of dead keratinized cells produced by hair follicles
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

11. Structure of a Nail
Scale-like modification of the epidermis on the distal, dorsal surface of fingers and toes
Figure 5.7
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

12. Skin Cancer UV damages skin cells and produces cancer
UV intensity is getting higher due to reduction of ozone in atmosphere
Skin protection from UV is vital to body health

13. Dear 16 Year Old Me Video

14. Stop here Wednesday,

15. Immune System

16. General Characteristics:
The germ theory of disease – infectious diseases are caused by microorganisms
The body’s main defense against pathogens
Fights infection by producing cells that inactivate foreign substances or cells

17. Ways to Contract Pathogens:
Physical contact – Coughs, Sneezes, Touching objects, Sexual contact
Contaminated food or water
Animal vectors – Insects, Mammals, Birds

18. Disease:
Autoimmune diseases – immune system makes a mistake & attacks body’s own cells
Body fails to recognize “self” from “nonself” & produces “antiself” antibodies
Diabetes, rheumatoid arthritis, myasthenia gravis, multiple sclerosis

19. Disease (con’t) Human Immunodeficiency Virus
Replicates inside the cells of the immune system (Helper T4 Lymphocyte White blood cell)
Transmitted through exchange of body fluids (blood, semen, vaginal secretions, breast milk)

20. Two General Categories of Body Defense:
Nonspecific defenses
a. First line of defense is the skin
1. Acts as a barrier against infection
2. Oil & sweat glands produce acidic
environment that kills many bacteria

21. Two General Categories of Body Defense:
b. Secretions of body (mucus, saliva, tears) often contain an enzyme that breaks down the cell walls of many bacteria

22. Two General Categories of Body Defense:
c. Second line of defense – inflammatory response
When there is tissue damage, blood vessels near wound expand & white blood cells enter infected tissues (swelling)  lead to fever - immune system chemicals increase body temperature

23. Two General Categories of Body Defense:
Specific defenses
Antigen – foreign protein on a pathogen produces an immune response
Immune response involves two types of white blood cells
B cells – provide immunity against antigens & pathogens in body fluids
T cells – provide defense against abnormal cells & pathogens inside cells

24. How the Immune System Works:
Antigens of pathogen recognized by B cells
B cells grow & divide rapidly, producing plasma cells & memory B cells
a. Plasma cells release antibodies – proteins that recognize & bind to antigens
b. Memory cells remain after plasma cells die out &
help produce secondary response next time this
pathogen is encountered

26. General Characteristics:
T cells divide & differentiate into killer T cells, helper T cells, suppressor T cells, & memory T cells
Killer T cells track down & destroy cells containing pathogens
Helper T cells produce memory T cells
Memory T cells produce secondary response
Suppressor T cells shut down killer T cells as pathogens are brought under control

27. Types of Immunity or treatment:
Passive immunity – antibodies produced by other people or animals
Antibodies produced by mother passed to fetus across placenta or through breast milk

28. Types of Immunity or treatment:
Active immunity - Vaccines stimulate the immune system to create millions of plasma cells ready to produce specific types of antibodies
Antibiotics – kill bacteria without harming cells of host