Components and function of the protection system

1. Protection
Roger Watson
Twitter: @rwatson1955

2. Protection
We live in a hostile environment and require protection against:
•Oxygen
•Injury
•Poisoning
•Extremes of heat
•Dehydration
•Infection

3. Oxygen
Oxygen:
•Comprises approximately 20% of the air we breathe

5. Oxygen
Oxygen:
•Comprises approximately 20% of the air we breathe
•Is a highly toxic substance if breathed at higher concentrations

7. Oxygen
Oxygen:
•Comprises approximately 20% of the air we breathe
•Is a highly toxic substance if breathed at higher concentrations
•Produces active oxygen species:
• Superoxide
• Hydrogen peroxide
Mechanism exists to protect the body against the toxic effects of
oxygen at normal levels

9. Oxygen
Oxygen:
•Comprises approximately 20% of the air we breathe
•Is a highly toxic substance if breathed at higher concentrations
•Produces active oxygen species:
• Superoxide
• Hydrogen peroxide
Mechanism exists to protect the body against the toxic effects of
oxygen at normal levels
With ageing we become less able to protect ourselves against the
harmful effects of oxygen

10. ANTI-OXIDANT INDUSTRY

11. Reflexes
“an automatic instinctive unlearned reaction to a stimulus “

13. Vomiting
“the reflex act of ejecting the contents of the stomach through the
mouth “

16. The skin
Protects against:
• Physical damage
• Dehydration
• Extremes of heat
• Infection
The skin is the largest organ in the body

20. Bozeman biology You Tube link
Thermoregulation

21. Thermoregulation
Under control of the temperature regulating centres in the
hypothalamus

23. Thermoregulation
Under control of the temperature regulating centres in the
hypothalamus
Acts to redistribute blood between the core and the periphery of the
body depending on the ambient temperature

24. HOT COLD

25. Thermoregulation
Under control of the temperature regulating centres in the
hypothalamus
Acts to redistribute blood between the core and the periphery of the
body depending on the ambient temperature
Capillaries in skin adjust the amount of blood they carry according to
the ambient temperature

26. COLD
HOT

27. Thermoregulation
Under control of the temperature regulating centres in the
hypothalamus
Acts to redistribute blood between the core and the periphery of the
body depending on the ambient temperature
Capillaries in skin adjust the amount of blood they carry according to
the ambient temperature
Heat is then lost from the body by:
• Evaporation
• Radiation
• Convection
• Conduction

29. Wound healing
The skin is capable of repairing itself when it is broken
Wound healing takes place in three stages:
• Inflammation
• Proliferation
• Maturation

32. Wound healing
The skin is capable of repairing itself when it is broken
Wound healing takes place in three stages:
• Inflammation
• Proliferation
• Maturation
Blood clotting (haemostasis) also takes place to prevent blood loss

33. Bozeman biology You Tube link
Blood clotting

35. Wound healing
The skin is capable of repairing itself when it is broken
Wound healing takes place in three stages:
• Inflammation
• Proliferation
• Maturation
Blood clotting (haemostasis) also takes place to prevent blood loss
The process is a CASCADE whereby a small initial stimulus produces
a big response

38. Wound healing
The skin is capable of repairing itself when it is broken
Wound healing takes place in three stages:
• Inflammation
• Proliferation
• Maturation
Inflammation is a defensive mechanism which brings cells to the site
of injury which help to fight the infection and this also stimulates
wound healing – it is a necessary process.

39. Inflammation
Can be recognised by:
• Redness
• Heat
• Pain
• Swelling
• (loss of function)

40. Bozeman biology You Tube link
The immune system

41. Immunity
Two processes involved:
• Non-specific defences
• Specific defences

42. Immunity
Two processes involved:
Non-specific defences:
• Skin
• Macrophages
Specific defences:
• Cell mediated immunity
• Antigen mediated immunity

45. Macrophages
Literally ‘big eaters’

49. Macrophages
Literally ‘big eaters’
Also know as antigen presenting cells (APCs)
They ‘present’ antigens to the specific immune system

51. Macrophage
T-cell

53. Specific immune system
This is stimulated when the T-cells encounter an APC

55. Specific immune system
This is stimulated when the T-cells encounter an APC
It is also capable of ‘remembering’ previous infections by the
production of antibodies

56. Hinge region

59. Immunisation
We can exploit the immune system to our advantage to protect
against infectious diseases.
Immunisation works by presenting an attenuated form of an antigen to
the immune system
This stimulates the production of antibodies
Usually a second presentation of the antigen is required

62. Protection
We live in a hostile environment and require protection against:
•Oxygen
•Extremes of heat
•Dehydration
•Infection

63. Questions
1. In addition to injury and poisoning what else do we require
protection from?
2. Where are the symptoms of oxygen toxicity manifested?
3. In a reflex arc what is the correct order for: spinal cord; motor
neurone; muscle; sensory neurone?
4. Name four things that can stimulate the vomiting centre.
5. What four things does the skin protect against?
6. How is heat lost from the body?

64. Questions
7. Name the three stages of wound healing and in the correct order.
8. Briefly describe blood clotting.
9. What are the cardinal signs of inflammation?
10. Name the components of non-specific and specific defence
systems.
11. Describe active and passive immunity.

65. r.watson@hull.ac.uk
Four things about…(a simple approach to
anatomy and physiology)
Special Senses
r.watson@hull.ac.uk
Four things about…(a simple approach to
anatomy and physiology)
Protection