The primary lymphoid organs that create lymphocytes are the bone marrow and thymus. The bone marrow produces B cells and some T cells, while the thymus matures T cells. Secondary lymphoid organs where lymphocytes are activated include lymph nodes, the spleen, tonsils, appendix, and Peyer's patches in the intestine. These organs work to filter the lymph and blood, recognize and eliminate pathogens and foreign cells, and support immune system functions.

1. Uzma Bibi 1372
Laiba Suleman 1402
Hamnah Zubair 1365
Tasbiha Mukhtar 1360
SUBMITTED TO: Dr.Sadaf Moeez
BSBT-13 (B)
IMMUNOLOGY

2. IMMUNE
ORGANS
Of the Human Body

3. Lymphatic System
● Contains lymph, lymph vessels,
lymphocytes and lymph nodes.
● Lymph: is a watery fluid that contains
immune cells, and other substances
(lipids, proteins, vitamins, minerals,
waste products and pathogens).
● Lymph vessels: are tubes that carry
this fluid throughout the body.
● The lymphatic system collects this
protein-rich lymph fluid and passes it
through lymph nodes to filter out waste
products and pathogens (toxin, bacteria
and virus-free).

4. Organs

5. 01
Primary lymphoid organs
• Create lymphocytes (B cells and T cells),
the immune system needs to fight against
illness.
Bone Marrow
• The soft, spongy tissue that has many
blood vessels and is found in the center
of most bones.
• It is responsible for the production of
white blood cells, red blood cells and
platelets. Once created, they migrate to
other organs and tissues via blood.
• B cells are produced and matured in the
bone marrow while T cells travel to
thymus for maturation.

6. • B-lymphocytes make proteins called antibodies which
attach onto the surface of infection-causing
microbes to fight against future infection.
• Selection process within the bone marrow
eliminates B cells with self-reactive antibody
receptors.
02 Thymus
• Located above the heart.
• Most active during childhood.
• T cells are matured in the thymus.
• These cells find and destroy pathogens
like bacteria.
• T4 cells: alerts other white cells to
pathogens
• T8 cells: suppresses the activity of other
white blood cells
• Killer T cells: special type of T8 cells
that destroys foreign cells.

7. 03
Secondary lymphoid organs
• Where the Lymphocytes are activated to
defend against pathogens.
Lymph
Nodes
• Lymph nodes are small bean-
shaped organs (the size of a pea).
• Lymph nodes exist throughout your
body.
• For example in the Neck, Armpit,
Chest, Abdomen, and Behind your
ear.
• Your lymph nodes can swell, which
is a sign that your body is fighting
an infection.

8. • A lymph node’s job is to filter substances in your lymph
fluid.
• Destruction and elimination of bacteria and toxins,
carried out by the macrophages in lymph nodes.
• The nodes filter out the damaged cells and cancer cells.
04 Spleen
• Largest lymphatic organ, spleen is a
small organ inside your left rib cage,
just above the stomach.
• Stores blood
• Filters blood by removing cellular
waste and getting rid of old or
damaged blood cells.
• Makes white blood cells and
antibodies that help you fight infection.
• Maintains the levels of fluid in your
body.

9. 05
• are two round, fleshy masses in the
back of your throat (pharynx).
• Protect against foreign substances that
you inhale or ingest through the nose or
mouth.
• Once trapped in the tonsils, bacteria or
viruses are then transported to lymph
nodes, where specialized immune cells
cluster to fight infection.
• Your body’s first protective barrier.
Tonsils

10. 06 Appendix
• Appendix is a thin, roughly 4-inch-long
tube, part of our GI tract.
• Attached to a part of the large intestine
called the cecum.
• And was considered a vestigial organ
(that loses through centuries of evolution )
• Helps in the maturation of B cells, which
produces antibodies that attack the
pathogens.
• Storehouse of beneficial bacteria.
• Strengthens and supports the immune
system.
• the type of antibody produced inside it is
an immunoglobulin (IgA), which plays its
role in mucosal immunity.

11. 07 Peyer’s Patches
• PPs referred to the small masses of
lymphoid tissues.
• found in the lower part of the small
intestine known as the ileum.
• Roughly egg-shaped appearance.
• An adult has 30-40 pairs of Patches
on average.
• Also known as aggregated lymphoid
nodules.
• Analyze and respond to
Pathogenic microbes in ileum.
• Monitor and prevent bacterial
growth.

12. Step 2
Microfold cells
(lining the surface
of Peyer’s patches)
Step 4
B & T
Lymphocytes
Step 5
Immune Response
Step 3
Macrophages
Step 1
Antigen or
microbes
from the gut
Trigger
Endocytosis Absorbed
Transfer
Transfer to lymph
node- alert other
cells

13. Thank
You!