Unit IX: The Lymphatic System A&P BSN 1

At the completion of this unit, learners will be able to: 1. Define lymph & the lymphatic system 2. Identify the organs of lymphatic system 3. Describe the general functions of the lymphatic system 4. Describe how lymph is formed 5. Describe the lymph vessels & how lymph is returned to the blood vessels 6. Describe the structure and functions of the lymph nodes, nodules, spleen and the thymus glands.

1. Syed yousaf shah

2. By the end of this presentation learners
will be able to:
Define Lymph and Lymphatic System.
Discuss composition of Lymph.
List the organs of Lymphatic System.
Describe the Lymphatic ducts.
Discuss functions of Lymphatic System.

3. 

4. The Lymphatic System consist of :
Lymph
Lymph vessels
Lymph Nodes
Lymph organs e.g. Spleen and Thymus
Diffuse lymphoid tissues e.g. tonsils and
glands.
Bone marrow.

5. Latin lympha"water"
"Means clear water and it is basically the fluid and
protein that has been squeezed out of the blood
(i.e. blood plasma). The lymph is drained from
the tissue in microscopic blind-ended vessels
called lymph capillaries.
These lymph capillaries are very permeable, and
because they are not pressurized the lymph fluid
can drain easily from the tissue into the lymph
capillaries.

6. Lymph (now called chyle) consist of follow
components:
Plasma proteins
Bacteria and cell debris
Lymphocytes
Fats from small intestine.

7. Protein concentration of lymph is lower
than in plasma, 1.5% vs. 6% for plasma.
Specific proteins differ, for example
albumin is a smaller molecular size than
globulins and leaves the capillaries more
readily than globulins, so the albumin :
globulin ratio is 1.8 in plasma, 2.5 in
lymph.

8. Lymph Capillaries:

9. Originates as blind end tube in interstitial
space.
Lymphatic capillaries are slightly larger in
diameter than blood capillaries.
Similarly like blood capillaries i.e., a single
layer of endothelial cells. But their walls
are more permeable to cell proteins and
cell debris.
Join up form larger lymph vessel.
All tissues have network of lymph vessels
except CNS, Bones and most superficial
layer of skin.

10. The main purpose of these vessels is to
drain excess tissue fluids from around the
cell ready to be filtered and returned to the
Venous circulation.

11. Same thickness as small veins and same layers
of tissues:
Inner endothelium
Middle layer of smooth muscles
Fibrous covering
Semi lunar Valves:
Numerous Cup shaped valves
Make the flow of lymph one way towards “Thorax”

12. lymphatic system is a one-way street
draining lymph from the tissue and
returning it to the blood."
Unlike the cardiovascular system, the
lymphatic system is not closed and has
no central pumplike Heart.
Movement is due to muscle layer in walls
of larger lymph vessels.

13. Lymph movement occurs despite low
pressure due to peristalsis:
Larger vessels have intrinsic ability to
contract rhythmically.
Contraction of adjacent muscle and
pulsation of larger arteries.

14. Lymph vessels
Thoracic Ducts Right Lymphatic Duct
Sub clavian Vein

15. Begin at Cisterna Chyli (Dilated Lymph
channel)
Cisterna Chyli is situated in front of bodies
of 1
st
two Lumber vertebrae
Length; Thoracic duct is 40 cm long.
Open in to: Thoracic duct open into Left
Sub clavian vein in the root of neck.

16. Thoracic Duct drains lymph from:
Legs.
Pelvic and abdominal cavities.
Left half of the thorax
Head and Neck.
Left Arm.

17. This dilated lymph vessel about 1 cm long.
It lies in the root of the neck and opens in
to right subclavian vein.
It drains lymph from:
Right half of the Thorax,
Head and Neck.
Right Arm.

19. Lymph Nodes:
The lymph node is a component of the
lymphatic system.
Shape: These are bean-shaped organs.
Size:From a few millimeters to about 1-2
cm(pin head to size of almond) in their
normal state”.

20. The are often in groups, along the length
of lymph vessels.
Their main locations are:
The neck,
under the arms, and
In the groin.
Lymph drain from 8-10 lymph nodes before
entering the venous circulation.

21. Outer capsule(Fibrous Tissues)
This capsule dip down into the Node
substance.
Forming partition or Tuberculae
Substance:
Reticular Tissues
Lymphatic Tissues
Cells: Lymphocytes and Macrophages.
(Types of WBC)

22. 4-5 Afferent Lymph vesselsenters into
Lymph Node
One Efferent vesselscarries lymph away
from the node
Hilum:Concave surface located in the
middle of the Lymph node.
One artery enters, and
One vein and efferent vessel leaves from
the hilum.

24. Large no of Lymph nodes are located
throughout the body in superficial and
deep groups.
Cervical Nodes:Collect lymph from Head
and Neck
Axillary Nodes:Lymph from upper limb
first comes in to elbow region nodes then
in to Axillary Nodes.

25. Nodes close to Mediastinum, Large airway
andesophagus:Collect lymph from organs and
tissues in Thoracic cavity.
Axillary Nodes:Collect lymph from breast.
Lymph Nodes before entering Cisterna Chyli :
Collect lymph from pelvic and abdominal cavities
Nodes are situated mainly in association with
blood vessels supplying the organs & close to
the main arteries i.e. Aorta & External and
internal iliac arteries.

26. Nodes behind the knee & groin (inguinal
Nodes):
Collect the lymph from lower limb.

27. Each lymph node is also an important part
of your immune system.
Filtering and Phagocytosis:
Your lymph node filters fluids, viruses,
bacteria, and other waste materials.

28. Lymph enters in Lymph node
Filtered by Reticular and Lymphoid tissues.
Material Filtered in Lymph Node:
Microbes, Dead & Live phagocytes containing
ingested microbes
Malignant Tumors
Worn out & Damaged tissue cells.
Inhaled Particles.
Organic Material. (Destroyed by Macrophages &
Antibodies)

29. Some Inorganic Material (can not be
destroyed by phagocytosis). These
remains in macrophages either killing or
not damaging the cell.
Material not filtered in one node is filtered
in successive nodes.
As Lymph enter in blood is usually been
cleared of foreign material and cell debris.

30. Proliferation of T and B Lymphocytes:
Activated T and B Lymphocytes multiply in
Lymph Nodes.
Antibodies produced by B Lymphocytes
enter Lymph and Blood draining the node.

31. Processed by Thymus gland (situated
between Heart and Sternum)
Hormone Thymosin is promoting the
processing
Fully differentiated mature T Lymphocyte
recognize only one type of Antigen
React with only particular Ag. (e.g. Chicken
Pox)
Provide Cell Mediated Immunity.

32. Produced and process in Bone Marrow
Produce specific type of Antibody
These antibodies destroy only specific type
of Antigen.
It is called Antibody Mediated Immunity.

33. PRIMARY LYMPHOID ORGANS
Sites of lymphocyte maturation
BONE MARROW
All cells of the blood originate from
pluripotent stem cells in the bone marrow.

34. Tissue Drainage:
3-4 Liter of fluid from tissues is drained away by
the lymphatic vessels, and thus help maintain
fluid balance.
Absorption in Small Intestine
To absorb lipids from the intestine( via lymphatic
vessels in villi) and transport them to the blood."
Immunity:
To defend the body against disease by producing
lymphocytes.

35. Site:
It is located in the left upper quadrant of the
abdomen, just under the rib cage and lies
beneath the 9th to the 12th thoracic ribs.
Size:
11centimeters (4.3in) in length. It usually weighs
200grams (7.1oz)
Shape:
The spleenis a spongy, soft organ about as big
as a person's fist.

36. Red pulp Mechanicalfiltration of red
blood cells.
White Pulp: Active immune response
through humoral and cell-mediated
pathways.
Composed of nodules, called Malpighian
corpuscles. These are composed of:

38. THANK YOU