1. Animal Systems: DEFENSE Integumentary, Immune and
Lymphatic Systems

2. DEFENSE
How do the integumentary, immune and lymphatic systems work together to defend the body?
These systems work to protect the body from pathogens. The integumentary system (skin) is the first barrier against infection, and any invading pathogens are destroyed and removed via the immune and lymphatic systems.

3. Integumentary System
Integument – Latin “to cover”

4. Functions of the Integumentary System
Purpose:
Protection :
Protects deeper tissues (organs)
Blocks UV radiation
Prevents infectious agents from entering the body
Aids in temperature regulation (sweat or shiver)

5. Functions of the Integumentary System cont.
Prevents dehydration
Produces Vitamin D – from sunlight
Vitamin D increases absorption of calcium for healthy bones
Aids in excretion of wastes (salts)
Sensory organ (heat, cold, pressure and pain receptors)

6. Parts of the System: Skin is composed of three layers:
Epidermis – outer layer, site of rapid cell division (mitosis), production of keratin and melanin.
Melanocytes – give skin pigmentation and protect from UV rays
Dermis – inner layer, contains major structures of skin
Collagen, blood vessels, nerve endings, glands, sensory receptors, hair follicles
Subcutaneous fat – adipose tissue, provides insulation for body

7. Evolutionary Trends of Integumentary System
Simple
Complex
Animal
Taxon
Simple Invertebrates
Vertebrates
Adaptations
Simple integumentary system used predominantly for diffusion. Diffusion allows movement of gases, nutrients, fluids, and wastes products in and out of the organism to maintain homeostasis.
More complex integumentary system. Used to maintain internal body temperature, fluid and salt levels. Contains nerve receptors, glands, subcutaneous fat, hair follicles to interpret environmental stimuli.
Picture of Adaptation
Some organisms contain structures such as feathers, scales, and mucous glands for additional protection and support
Examples
Jellyfish, Flat worms, Earthworms, Sponges
Mammals, Reptiles, Amphibians, Fish, Birds

8. Integumentary System Levels of Organization
Epidermis, Dermis
Skin
Integumentary
Epithelial Cells (skin cells)

9. Fun Fact: Believe it or not, the integumentary system is the largest organ system and your skin is the largest organ in your body.

10. Interaction with Other Body Systems
Skin is the first line of defense in the immune system response.
The circulatory system and skin regulate body temperature.
Skin and the excretory system excrete water, urea, salts, and other wastes through sweat.
Receptors of the nervous system are located in skin.

11. THINK-PAIR-SHARE

12. Dear 16-Year-Old Me

13. Lymphatic System Purpose:
Collects fluid lost by the blood during movement of nutrients into body tissues and returns it back to the circulatory system.
Plays a role in the immune system by producing, storing and circulating white blood cells.
Network of vessels and associated organs:
1. lymph – fluid in lymph vessels
2. lymph vessels – move the lymph
throughout the body
3. lymph nodes - densely packed
areas of tissue that filter the lymph;
white blood cells are stored in them

14. 4. Tonsils, thymus and spleen are all composed of lymphoid tissue
tonsils – filter and destroy bacteria
thymus – produces hormones that aid in maturation of T-cells; T-cells
recognize foreign pathogens
spleen – removes worn-out red
blood cells from circulatory system;
contains white blood cells that
engulf and destroy bacteria.

15. To review:
The lymphatic system removes fluid from around cells and returns it to the blood.
When this fluid passes through the lymph nodes white blood cells attack and kill any pathogens.

16. Interactions with other Body Systems
Lymphatic system works with the circulatory system to maintain homeostasis of body fluids.
Lymphatic system plays a role in the immune system by producing white blood cells and destroying pathogens within lymph nodes and spleen.
The excretory system excretes excess fluids.

17. Immune System
Purpose: The immune system protects the body from disease by producing specialized cells that inactivate or destroy pathogens.

18. Parts of the System - consists of specialized cells and organs
Parts of the System - consists of specialized cells and organs that respond to the presence of a pathogen
skin – body’s first line of defense (also part of integumentary system)
white blood cells – recognize disease agents (antigens) and create antibodies to tag and remove these antigens. Macrophages are the white blood cell type that actually eat and destroy these antigens.
Macrophage of a mouse stretching its “arms” (pseudopodia) to engulf 2 pathogens

19. How the Immune System works:
1. First line of defense (pathogen does not enter body)
Skin & other non-specific defenses such as mucous, saliva, and tears trap and destroy pathogens.

20. 2. Second line of defense (pathogen enters body)
If pathogen does enter the body, this triggers the inflammatory response – Tissue becomes swollen and painful due to white blood cell accumulation.

21. Chemicals are released by immune system to cause fever (increased body temperature); increased temperature can kill some bacteria and viruses.
White blood cells called macrophages engulf and destroy pathogens.

22. 3. Third line of defense (pathogen gets past first and second
3. Third line of defense (pathogen gets past first and second line of defense)
Immune response
1. Triggered by an antigen; virus, bacteria or other pathogen.
2. T cells and B cells recognize the
specific pathogen and produce
antibodies that will help destroy
the invader and protect us the next
time it enters the body. This process
is called immunity.
3. The reaction to a second infection by
the same pathogen is much faster.
Antigen
Antibody
Antigen binding sites

23. Lymph & Immune System Levels of Organization
Lymph nodes, bone marrow
Spleen, Liver
Lymph and Immune
White Blood Cells, B-cells, T-cells, macrophages

24. **H.I.V. is the virus that causes AIDS, or acquired immune deficiency syndrome. It attacks a special T cell known as a helper T cell.
**Penicillin and other antibiotics can also be used to
help the immune system, but it is important to remember that antibiotics only kill bacteria!
**Vaccines work by mimicking the body’s natural
immune response. A small amount of the specially
treated virus, bacterium or toxin (vaccine) is injected
into the body. The body then makes antibodies. If a vaccinated person is exposed to the actual virus, bacterium or toxin, they won’t get sick.

25. Interactions with other Body Systems
Skin of the integumentary system is the first line of defense of the immune system.
The circulatory system transports immune cells around the body.
Bones of the skeletal system produce lymphocytes and macrophages.