1. Lymphatic System and Body Defense Chapter 16

2. Lymphatic System
Lymphatic system consists of lymphatic vessels, lymphatic organs and associated lymphoid tissue
Functions contribute to homeostasis
Helps defend body against disease
Lymphatic capillaries take up excess tissue fluid and proteins , and return it to bloodstream
Lacteals receive lipoproteins and transport them to bloodstream.

3. Lymphatic Organs
Thymus Lymph nodes Spleen

4. Major Organs of Lymphatic System

5. Lymphatic System

6. Lymphatic Capillaries
Microscopic
Closed-ended tubes with flap like valves
Found in interstitial spaces of most tissues
Attached via proteins to surrounding connective tissue remain open
Closely associated with the circulatory system

7. Lymphatic Vessels One-way system that carry lymph
Valves prevent backflow
Lymphatic capillaries absorb excess fluid

8. Lymph - fluid in lymphatic system
Lymph Function
Lymphatic capillary
Interstitial spaces
Lymph - fluid in lymphatic system
Increasing hydrostatic pressure within interstitial spaces forces tissue fluid into lymphatic capillaries
This process prevents accumulation of excess tissue fluid or edema

9. Lymph Movement respiratory movements
action of skeletal muscles
respiratory movements
smooth muscle in larger lymphatic vessels
valves in lymphatic vessels

10. Lymph Nodes Macrophages and lymphocytes
Filter potentially harmful particles from lymph
Areas of lymphocyte production

12. Obstruction of Lymph Movement
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Conditions that interfere with lymph movement
Fluid to accumulate in interstitial spaces
Results in edema
Lymphatic
vessels
Lymph
node
Muscle
Blood
vessels
© Dr. Kent M. Van De Graaff

13. Spleen Largest lymphatic organ Function Protection from pathogens,
removes aged RBC recycles Fe
Blood , platelets, monocyte reservoir
Fetal blood cell production but not after birth

14. Spleen Contains two tissue types White pulp lymphocytes
Immune functions
Red pulp
Red blood cells
Lymphocytes
Macrophages
Worn out RBC and pathogens are destroyed

15. Thymus Secretes thymosins Site of T lymphocyte maturation
Shrinks with age

16. Mucosa-Associated Lymphoid Tissues (MALT)
Peyer’s Patches
Lymphoid follicles in appendix
Tonsils of the pharynx and oral cavity
Follicles in urogenital and respiratory tract
They prevent pathogens in these passages from penetrating mucous membranes

17. Diseases of the Lymphatic System
Lymphatic filariasis
Facts from WHO
Nearly 1.4 billion people in 73 countries worldwide are threatened by lymphatic filariasis, a parasitic infection that leads to a disease commonly known as elephantiasis.
Over 120 million people are currently infected, with about 40 million disfigured and incapacitated by the disease. .