types of circulatory system, function of lymphatic system, components of lymphatic system, and explaination of these components, formation of lymph and factors contributing ti n the drainage of lymph, types of lymphoid organ, blood supply of lymphoid organ clinical aspect

1. LYMPHATIC
SYSTEM
By:
Dr SANA YASEEN
LECTURER ANATOMY DEPARTMENT
JMDC

2. INTRODUCTION
 Second Circulatory system of body
 Also referred as Drainage system of coarse type
 Venous system is called as Drainage system of
fine type

3. CIRCULATORY
SYSTEM

4. FUNCTIONS
1. Drains excess tissue fluid to venous system
2. Absorbs fat and fat soluble vitamins, A,D, E, K
from intestine & transport it to blood
3. Helps to provide immunological defense
against disease causing agents (particular
microbes)

5.  LYMPH
 LYMPHCAPILLARIES
 LYMPH VESSELS
 LYMPH TRUNKS & DUCTS
 LYMPH ORGAN
a. Lymph nodes
b. Spleen
c. Thymus
d. Bone marrow
 Epithelio-lymphoid system
COMPONENTS

6. LYMPH
 Is the tissue fluid that enters the lymph
capillaries
 It is clear watery fluid similar in
composition to plasma with exception of
plasma protein.

7. Composition of lymph
 Lyphocytes – 1000-2000/mm3
 Plasma cells
 Electrolytes same as plasma
 Urea, aminoacis, creatinine same as plasma
 Protein, calcium phosphorus lower than plasma
 Chloride and glucose more than plasma
 Clottin factors, plasma enzumes and antibodies

9.  Lymph
capillaries in
intestine is
called
LACTEALS.
 Lymph from
small
intestine is
milky white
called CHYLE
as it contains
fat droplets.

10. LYMPH CAPILLARIES
 Are microscopic blind ended sacs of smallest
lymph vessels which begin in inter cellular space.
 Walls of lymph capillaries are similar to blood
capillaries, but are more permeable.
 Abundant: skin, glands, mucous, serous
membrane.
 Absent: epidermis, hari, nail, cornea, articular
cartilage, brain & spinal cord, bone marrow,
splenic pulp.

12. FLOW OF LYMMPH INTO THE LYMPHATICS
CAPILLARIES

14. FACTORS INFLUENCE FORMATION
OF LYMPH
Increase hydrostatic pressure
Increase capillary surface
Increase capillary permeability
(hypoxia, bradykinin, histamin)
Increase functional activity

16. Difference between blood and lymph
capillaries
LYMPH CAPILLARIES BLOOD CAPILLARIES
Colorless, difficult to observe Reddish, easy to observe
Blind ends Joins arterioles & venules
Wider lumen Narrower lumen
Wall consist of thin
endothelium & poorly
developed basement
membrane
Wall consist of normal
endothelium & well
developed basement
membrane
Lymph-colorless Blood-red
Low pressure Relatively high pressure
Absorbs tissue fluid from
inter cellular space
Add and absorbs tissue fluid

17. LYMPH VESSELS
 Union of lymph capillaries
 Thin walled vessels, Dia 0.5-1mm
 They posses numerous valves within them- beaded
appearance
 The flow of lymph is in uni-direction towards large veins.
 Types of lymph vessels:
 Superficial: in superficial fascia, drains into deep lymph
vassels
 Deep : in deep fascia & accompany the blood vessels

18.  Before lymph is drained
into venous system it
passes through number
of filter stations/ barriers
called LYMPH NODES.
 These nodes purify the
lymph

19.  As lymph vessels exist lymph nodes in particular
region of body they unite to form lymph trunks. The
principal trunks are:
 Lumbar, intestinal, bronchomediastinal, subclavian
and jugular trunks.

20. LYMPHATIC DUCTS
There are principally two large lymphatic trunks
draining the lymph from whole body:
1. THORACIC DUCT
2. RIGHT- LYMPHATIC DUCT

21. THORACIC DUCT
 Is largest lymphatic duct (45cm long) in the body
 Origin: sac like dilated lymph channel called CYSTERNA
CHYLI.
 Terminate: angle between L-internal jugular vein & left
subclavian vein
 Area drains:
 Abdomen
 L-thoracic region
 L- upper limb
 L side of head and neck

23. RIGHT- LYMPHATIC DUCT
 Is dilated vessel of 1 cm long
 Lies in root of neck on right side & is formed by
union of 3 vessels:
1. R- jugular trunk
2. R- subclavian trunk
3. R – broncho-mediastinal trunk
 Terminates: open into angle between Right
brachicephalic vein & Right sbclavian vein
 Area drain:
 right upper limb
 Right side of head and neck
 Right thoracic region

25. FACTORS CONTRIBUTING IN DRAINAGE
OF LYMPH
 Muscle tissues in the walls of large lymph vessels has intrinsic ability
to contract rhythmically & so called “lymphatic pump”
 Pulsation of arteries lying near lymph vessels
 Massing action from contraction of surrounding muscles
 Filteration pressure in tissue spaces generated by filteration of fluid
from blood capillaries
 Respiratory movement
 Negative pressure in brachio-cephalic trunk
 Valves within the lumen of vessels

26. LYMPHOID ORGANS
 Are composed of specialised connective tissue
cells called Lymphatic tissue:
Composed of :
 Reticular framework
 Lymphocytes, plasma cells, macrophages

27. TYPES OF LYMPHOID ORGANS
PRIMARY/ CENTRAL:
 Eg, bone marrow, thymus
 Involve in the production of lymphocytes
SECONDARY/ PERIPHERAL:
 Eg , lymphnodes, spleen, epithelio lymphoid
tissue.
 Activation of lymphocytes

28. LYMPH NODE
 Oval shaped
 1-25mm long
 Along course of lymph vessels
 Occur in cluster/groups in specific region.
Ex. Cervical LN – neck
Axillary LN- upper limb
Mediastinal – thorax
Aortic & mesenteric LN- abdomen
Iliac LN – pelvis
Popliteal & inguinal LN- lower limb

29. INTERNAL STRUCTURE OF LYMPH NODE
 Has depression on one side called hilum
Composed of
 Outer fibrous capsule
 Inner ground substance (parenchyma)
 Outer cortex
 Inner medulla

31. CAPSULE:
 Is fibrous structure
 From its deep surface a number of trabeculae
extend into ground substance
 Trabeculae are accompanied by para trabecular
spaces which are continuous with sub capsular
sinus.
SUBCAPSULAR SINUS:
 Is subcapsular space that separates the capsule
from gland substance
 Surrounds node except the hilum

33. CORTEX:
 On basis of distribution of B & T lymphocytes it is
divided into:
 Outer cortex: immature B-lymphocytes
 B-lymphocytes forms variable number of densely
packed lymphoid follicles/nodules
 Many of these nodules shows less denser area called
GERMINAL CENTRES. Are areas of rapid lymphocytes
division & occupied by lymphoblasts & plasmoblasts
 INNER PARACORTEX: contain T-lymphocytes (thymic
dependent zone)

35.  PRIMARY LYMPHOID NODULE: follicles without
germinal centre
 SECONDARY LYMPHOID NODULE: follicles with
germinal centre
MEDDULA:
 Central part of lymphnode
 Contain network of anastomosing cords of cells
called Medullary cords
 Cells present are: B-lymphocytes (mature)
plasma cells
macrophages

37. CIRCULATION OF LYMPH

39. BLOOD FLOW THROUGH LYMPHNODES

40. CLINICAL ASPECTS
 LYMPHADINITIS:inflammation of lymphnodes
 LYMPHANGITIS: inflammation of lymph vessels

41. ELEPHANTIASIS
CAUSATIVE ORGANISM: filarial parasite
Mechanism: lives in lymphatics which may become
blocked leading to solid edema in peripheral area
of drainage

43. LYMPHOMA
 Blood tumor
occuring in
lymphatic system
Types:
 Hodgkin’s
lymphoma
 Non hodgkin’s
lymphoma

44. BURKITTS LYMPHOMA