what is innate immunity, its mechanism, principal, diagrams, features of innate immunity, factors affecting innate immunity, mechanism described by the help of diagrams and also the different barriers of innate immunity.

1. Presented by
SWATI SUMAN
B.Sc BT (2018-2021)5th sem
A35204418013

2. INTRODUCTION
•Innate immunity is an evolutionary old defense
system that generates a fast inflammatory response
that is generic to all types of pathogens or tissue
damages and does not confer immune memory to
the host.
• The innate immune system is essentially made up
of barriers that aim to keep viruses, bacteria,
parasites, and other foreign particles out of your
body or limit their ability to spread and move
throughout the body.

3. FEATURES OF INATE
IMMUNITY
1. Phylogenetically older
2. Non specific
3. Immediate and rapid
4. Needs not prior exposure
5. Not associated with memory

4. LEVELS OF INATE IMMUNITY

5. FACTORS AFFECTING INNATE
IMMUNITY

6. • AGE :-
1. Extreme age attracts infection, diseases very fast as our
immunity system gets weak.
2. New born are more susceptible to infection due to
immature immune system.
• HORMONES
1. Diabetes melatus
2. Hypothyroidism
3. Pregnancy (high steroid state)
4. Stress
• NUTRITION
1. Complex mechanism
2. Reduced cell mediated and humoral immunity.

7. The innate immune system includes:
Physical barriers ( physical barriers)
• Such as skin, the gastrointestinal tract, the respiratory tract, the
nasopharynx, cilia, eyelashes and other body hair.
Defense mechanisms
• Such as secretions, mucous, bile, gastric acid, saliva, tears, and sweat.
General immune responses
• Such as inflammation, complement, and non-specific cellular responses.
The inflammatory response actively brings immune cells to the site of an
infection by increasing blood flow to the area.

8. Physical barriers
Physical barriers (First line of defense)
• The body's most important nonspecific defense
is the skin, which acts as a physical barrier to
keep pathogens out. Even openings in the skin
(such as the mouth and eyes) are protected by
saliva, mucus, and tears, which contain an
enzyme that breaks down bacterial cell walls.

10. • Skin
• The skin is the largest organ of your body. It acts as a barrier
between invaders (pathogens) and your body. Skin forms a
waterproof mechanical barrier. Microorganisms that live all over
your skin can’t get through your skin unless it’s broken.
• Tears, mucus and saliva
• tears, mucus and saliva contain an enzyme that breaks down the cell
wall of many bacteria. Those that are not killed immediately are
trapped in mucus and swallowed. Special cells line and protect the
nose, throat and other passages within your body.
• Cilia
Very fine hairs (cilia) lining your windpipe move mucus and trapped
particles away from your lungs. Particles can be bacteria or material
such as dust or smoke.

11. • Stomach acid
Stomach acid kills bacteria and parasites that have
been swallowed.
• Urine flow
Our urine flow flushes out pathogens from the bladder
area.
• ‘Friendly’ (beneficial) bacteria
We have beneficial bacteria growing on your skin, and
other body parts that stop other harmful bacteria from
taking over.
• Neutrophils
These are white blood cells that can find, kill
and ingest pathogens seeking an entrance into the
body.

12. Second line of defense
• If a pathogen does make it into the body, there are secondary
nonspecific defenses that take place.
• An inflammatory response begins when a pathogen stimulates an
increase in blood flow to the infected area. Blood vessels in that area
expand, and white blood cells leak from the vessels to invade the
infected tissue. These white blood cells, called phagocytes engulf and
destroy bacteria. The area often becomes red, swollen, and painful
during an inflammatory response.
• When a pathogen has invaded, the immune system may also release
chemicals that increase body temperature, producing a fever.
Increased body temperature may slow or stop pathogens from growing
and helps speed up the immune response.

14. THANKYOU