1. Principles of Human Anatomy and Physiology, 11e

2. The Lymphatic System Lecture Outline Understanding of lymph tissues
Dynamic of lymphoid tissues
Distribution of Lymphoid tissues

3. Skin=2m2 Respiratory= 100m2 Gut =400m Vascular tree= km Velocity of lymphocyte in main vessel=0.5m/second Velocity of lymphocyte in o.vessel=0.5mm/second total lymphoid cell in blood is 1x1011 total lymphoid cell in stationary is 9x1011
Principles of Human Anatomy and Physiology, 11e

4. Introduction The Lymphatic SYSTEM STRUCTURE
Immunophysiology of Lymphatic S
Development of Lymphatic tissues
Principles of Human Anatomy and Physiology, 11e

5. Lymphatic System Organs, vessels and a fluid called lymph
similar to interstitial fluid
Organs involved
red bone marrow
thymus
spleen
lymph nodes
diffuse lymphatic tissue
tonsils, adenoids & peyers patches
Principles of Human Anatomy and Physiology, 11e

6. Skin=2m2 Respiratory= 100m2 Gut =400m Vascular tree= km Velocity of lymphocyte in main vessel=0.5m/second Velocity of lymphocyte in o.vessel=0.5mm/second total lymphoid cell in blood is 1x1011 total lymphoid cell in stationary is 9x1011
Principles of Human Anatomy and Physiology, 11e

7. Principles of Human Anatomy and Physiology, 11e

8. Principles of Human Anatomy and Physiology, 11e

9. Principles of Human Anatomy and Physiology, 11e

10. Principles of Human Anatomy and Physiology, 11e

11. Principles of Human Anatomy and Physiology, 11e

12. Principles of Human Anatomy and Physiology, 11e

13. Thymus Gland Figure 22.5
Large organ in infants (70 g) but atrophied as adult (3 g)
2 lobed organ located in mediastinum
Capsule & trabeculae divide it into lobules
Each lobule has cortex & medulla
Cortex
tightly packed lymphocytes & macrophages
Medulla
reticular epithelial cells produces thymic hormones
Hassall’s corpuscles
Principles of Human Anatomy and Physiology, 11e

14. Thymus Gland
Large organ in infants (70 g) but atrophied as adult (3 g)
2 lobed organ located in mediastinum
Capsule & trabeculae divide it into lobules
Each lobule has cortex & medulla
Cortex
tightly packed lymphocytes & macrophages
Medulla
reticular epithelial cells produces thymic hormones
Hassall’s corpuscles
Principles of Human Anatomy and Physiology, 11e

15. Thymus Gland
Large organ in infants (70 g) but atrophied as adult (3 g)
2 lobed organ located in mediastinum
Capsule & trabeculae divide it into lobules
Each lobule has cortex & medulla
Cortex
tightly packed lymphocytes & macrophages
Medulla
reticular epithelial cells produces thymic hormones
Hassall’s corpuscles
Principles of Human Anatomy and Physiology, 11e

16. Lymphatic Nodules
Concentrations of lymphatic tissue not surrounded by a capsule scattered throughout connective tissue of mucous membranes
mucosa-associated lymphoid tissue (MALT)
Peyer’s patches in the ileum of the small intestine
Appendix
Tonsils form ring at top of throat - Figure 23.2
adenoids (pharyngeal tonsil)
palatine tonsils (on each side wall)
lingual tonsil in the back of the tongue
Principles of Human Anatomy and Physiology, 11e

17. Lymph Nodes - Overview
Lymph nodes are encapsulated oval structures located along lymphatic vessels (Figures 22.1a and 22.6).
They contain T cells, macrophages, follicular dendritic cells, and B cells.
Lymph enters nodes through afferent lymphatic vessels, is filtered to remove damaged cells and microorganisms, and exits through efferent lymphatic vessels.
Foreign substances filtered by the lymph nodes are trapped by nodal reticular fibers.
Macrophages then destroy some foreign substances by phagocytosis and lymphocytes bring about the destruction of others by immune responses.
Lymph nodes are the site of proliferation of plasma cells and T cells.
Knowledge of the location of the lymph nodes and the direction of lymph flow is important in the diagnosis and prognosis of the spread of cancer by metastasis; many cancer cells are spread by way of the lymphatic system, producing clusters of tumor cells where they lodge. (Clinical Application)
Principles of Human Anatomy and Physiology, 11e

18. Lymph Nodes Flow is in one direction afferent vessels lead in
sinuses lead to efferent vessels that exit at hilus
Only nodes filter lymph
Principles of Human Anatomy and Physiology, 11e

19. Principles of Human Anatomy and Physiology, 11e

20. Spleen Figure 22.7 5 inch organ between stomach & diaphragm
Hilus contains blood & lymphatic vessels
Stroma consists of capsule, trabeculae, fibers & fibroblasts
Parenchyma consists of white pulp and red pulp
white is lymphatic tissue (lymphocytes & macrophages) around branches of splenic artery
red pulp is venous sinuses filled with blood & splenic tissue (splenic cords)
Principles of Human Anatomy and Physiology, 11e

21. Circulation of Lymphatic system
Principles of Human Anatomy and Physiology, 11e

22. Functions of the Lymphatic System
Draining excess interstitial fluid & plasma proteins from tissue spaces
Transporting dietary lipids & vitamins from GI tract to the blood
Facilitating immune responses
recognize microbes or abnormal cells & responding by killing them directly or secreting antibodies that cause their destruction
Principles of Human Anatomy and Physiology, 11e

23. Lymphatic Vessels and Lymph Circulation
Lymphatic vessels begin as blind-ended lymph capillaries in tissue spaces between cells (Figure 22.2).
Interstitial fluid drains into lymphatic capillaries, thus forming lymph.
Lymph capillaries merge to form larger vessels, called lymphatic vessels, which convey lymph into and out of structures called lymph nodes (Figure 22.1).
Principles of Human Anatomy and Physiology, 11e

24. Principles of Human Anatomy and Physiology, 11e

25. Lymphatic Vessels & Circulation
Capillaries that begin as closed-ended tubes found in spaces between cells
Combine to form lymphatic vessels
resemble veins with thin walls & more valves
Fluid flows through lymph
nodes towards large veins
above the heart
lymph emptied into bloodstream
Principles of Human Anatomy and Physiology, 11e

26. Lymphatic Capillaries
Lymphatic capillaries have a slightly larger diameter than blood capillaries and have overlapping endothelial cells which work as one-way valves for fluid to enter the lymphatic capillary.
Anchoring filaments attach endothelial cells to surround tissue (Figure 22.2).
A lymphatic capillary in the villus of the small intestine is the lacteal. It functions to transport digested fats from the small intestine into blood.
Principles of Human Anatomy and Physiology, 11e

27. Lymphatic Capillaries
Found throughout the body except in Avascular tissue (cartilage, epidermis & cornea)
Structure is designed to let tissue fluid in but not out
anchoring filaments keep tube from collapsing under outside pressure
overlapping endothelial cells open when tissue pressure is high (one-way valve)
Principles of Human Anatomy and Physiology, 11e

28. Lymph Trunk and Ducts
The principal lymph trunks, formed from the exiting vessels of lymph nodes, are the lumbar, intestinal, bronchomediastinal, subclavian, and jugular trunks (Figure 22.3).
The thoracic duct begins as a dilation called the cisterna chyli (Figure 22.4) and is the main collecting duct of the lymphatic system.
The thoracic duct receives lymph from the left side of the head, neck, and chest, the left upper extremity, and the entire body below the ribs.
It drains lymph into venous blood via the left subclavian vein.
Principles of Human Anatomy and Physiology, 11e

29. Lymph Trunks & Ducts Vessels unite to form trunks & thoracic ducts
Right side head, arm & chest empty into right lymphatic duct and rest of body empties into thoracic duct
Lymph is dumped directly into left & right subclavian veins
Principles of Human Anatomy and Physiology, 11e

30. Principles of Human Anatomy and Physiology, 11e

31. Principles of Human Anatomy and Physiology, 11e

32. Immunophysiology of Lymphatic system Lymphatic System Transport by lymphatic system Lymphatic circulation Mechanism of filtration
Principles of Human Anatomy and Physiology, 11e

33. Lymphatic System Thin wall in all tissues Intersitial fluid Thorasic duct Dynamic of fluid Starling hypothesis Drinker hypothesis Selection hypothesis
Principles of Human Anatomy and Physiology, 11e

34. Principles of Human Anatomy and Physiology, 11e

35. Transport by lymphatic system Fatty acids labelled with radioactive carbon a-short fatty acids—intestine--blood--liver—Metabolize b-long fatty acids– intestine—lymph Hormones from tissues to blood
Principles of Human Anatomy and Physiology, 11e

36. Lymphatic circulation capillary (thin)----Vessel Elastic fiber systerna chylii transport 500cc /hour
Principles of Human Anatomy and Physiology, 11e

37. Mechanism of filtration 1-Pumping action of lymphatic vessels = effect tissues motion = action of terminal lymphatic capillary 4-the pressure of fluid in the tissues space
Principles of Human Anatomy and Physiology, 11e

38. Lymphatic traffic ( In normal condition) 1-Lymph circulate through gut associated lymph tissues---blood---PP----mesenteric lymph node-----Thorasic duct --- heart 2-Skin---peripheral LN----Central LN---thorasic duct---heart 3-Recirculate through lymphoid organ LN---LN Lymphocyte reticulate through spleen blood spleen blood spleen--- miner ---lymph 4-lymphocyte recirculation through to thorasic duct
Principles of Human Anatomy and Physiology, 11e

39. Lymphatic traffic ( In abnormal condition) 1-Lymphocyte circulate through gut associated---lesion-- lymph tissues---blood---PP----mesenteric lymph node-----Thorasic duct --- heart 2-Lymphocyte crculate through Skin---infalammation---peripheral LN----Central LN---thorasic duct---heart 3-Recirculate through lymphoid organ—infammation in organ--- LN---LN
Principles of Human Anatomy and Physiology, 11e

40. Kinetic of flow in L.N
Principles of Human Anatomy and Physiology, 11e

41. Principles of Human Anatomy and Physiology, 11e

42. Principles of Human Anatomy and Physiology, 11e

43. Development Lymphatic tissues Emberyonic adults
Principles of Human Anatomy and Physiology, 11e

44. DEVELOPMENT OF THE LYMPH TISSUES
Lymphatic vessels develop from lymph sacs, which develop from veins. Thus, they are derived from mesoderm.
Lymph nodes develop from lymph sacs that become invaded by mesenchymal cells (Figure 22.8).
Principles of Human Anatomy and Physiology, 11e

45. Developmental Anatomy
Begins to develop by 5th week
Lymphatic vessels develop from lymphatic sacs that arise from veins
Jugular sac & cisterna chyli form thoracic duct
Sacs develop into lymph nodes
Spleen develops in gastric mesentery
Thymus is outgrowth of 3rd pharyngeal pouch
Principles of Human Anatomy and Physiology, 11e