Immune System

1
Immune System

• Chapter 21

2
Stress

• Stress ? secrete lots of steroids ? suppress the
  immune system ? get sick more often or more
  easily

3
Introduction

• Immunity
• The human bodys defense system

4
First Line of Defense

• Mechanical Barriers
• Intact skin
• Mucous membranes

5
First Line of Defense

• Chemical Barriers wash away microorganisms
• Tears
• Saliva
• Perspiration

6
First Line of Defense

• Reflexes
• Sneezing
• Coughing
• Vomiting
• Diarrhea

7
Second Line of Defense

• Phagocytosis
• Destruction of pathogens by ingestion from WBCs

8
Second Line of Defense

• Inflammation (bodys response to an irritant)
• Redness
• Heat
• Swelling
• Pain

9
Second Line of Defense

• Severe infections have pus
• Dead leukocytes
• Pathogens
• Injured cells
• Tissue fluid

10
Second Line of Defense

• Fever (pyrexia)
• Beneficial to the body
• Stimulates phagocytosis
• Decreases ability of pathogens to multiply

11
Second Line of Defense

• Reducing a fever may prolong an infection!!

?
12
Third Line of Defense

• Specific immunity provides protection against one
  specific substance
• Measles (one example)

13
Third Line of Defense

• Antigens
• Stimulate formation of antibodies
• Found on surfaces of many substances
• Most are proteins

14
Third Line of Defense

• Autoimmune diseases
• Occur when the immune system attacks its own
  cells

15
Third Line of Defense

• Primary Response
• Initial response to an antigen
• Slow development
• Secondary Response
• Quick response
• Produces larger number of antibodies
• Now immune to the disease (wont get it)

16
Types of Immunity

• Genetic immunity
• Born with it
• Your species protects you
• Cant get what dogs get!

17
Types of Immunity

• Acquired Immunity
• Received during a persons lifetime
• Comes naturally or artificially

?
18
Naturally Acquired Immunity

• Obtained one of two ways
• By getting the disease
• By receiving antibodies from your mom

19
Naturally Acquired Immunity

• Active Immunity
• Obtained by getting the disease
• Lasts a lifetime
• Body produces antibodies

20

• Passive Immunity
• Obtained by receiving antibodies from your mom
• Lasts a short time
• Antibodies received from mom through
• Placenta
• Breast milk

21
Artificially Acquired Immunity

• Get it one of two ways
• Vaccine
• Injection of immune globulin

22
Artificially Acquired Immunity

• Vaccine
• An antigen-bearing substance, such as a pathogen,
  injected into a person in an attempt to stimulate
  antibody production
• This cannot cause the disease
• Purpose is to make memory cells
• Purpose of a booster shot is to stimulate the
  secondary response
• A form of active immunity

23
Artificially Acquired Immunity

• Immune Globulin
• Obtained from a donor
• Contains antibodies (immune globulins)
• A form of passive immunity
• Can provide immediate protection

Hepatitis B
24
Allergic Reactions

• When the body forms antibodies to substances not
  usually recognized as foreign
• Allergens (antigens) are substances that induce
  an allergic response

Insect venom
Penicillin
Pollen
25
Allergic Reactions

• When the body releases large amounts of
  histamine, systemic effects occur.
• Hypotension
• Wheezing
• Difficulty breathing
• Death can occur!!

Anaphylactic Shock
26
Autoimmune Disease

• Two body systems affect your immune system
• Endocrine system
• Nervous system