Lymphatic System: Functions, Mechanism, and Lymphedema by Alila Medical Media

Lymphatic System Functions

1Three functions of the Lymphatic System 1. Lymph vessels take up excess tissue fluid and return it to the bloodstream. 2. Lacteals transport lipoproteins from the digestive tract into the bloodstream. 3. Works alongside the immune system to protect the body from disease.

Lymphatic Circulation Overview

2Lymphatic Circulation . A system of lymph vessels that collect excess tissue fluid from capillary beds and deposit that tissue fluid into the blood. · Lymph vessels provide one-way movement only because they have bicuspid valves. · Lymphatic vessels carry lymph to lymph nodes, which filter the lymph for pathogens.

Lymphatic System Mechanism

3Lymphatic System Alila MEDICAL MEDIAHow does it work? Lymph capillaries lie near the blood capillaries in the capillary beds so they can absorb any excess tissue fluid back into the blood capillaries.

Lymph capillaries in the tissue spaces Lymph capillary Tissue cells Collagen fiber Arteriole Interstitial fluid Venule 0 Lymph (interstitial fluid) Tissue fluid Lymphatic vessel Endothelial "flaps" Lymph vessel endothelial cells Backflow prevention valve U

Lymphedema Condition

5Lymphedema When lymph vessels are blocked and tissues swell with fluid. O MAYO FOUNDATION FOR MEDICAL EDUCATION AND RESEARCH. ALL RIGHTS RESERVED.Elephantiasis - severe swelling due to parasitic worms that block lymph notes or ducts.

Lymphatic System Components

• Lymph: The fluid carried within the lymph capillaries.
• Lymphocytes: white blood cells in the lymph nodes which fight pathogens.
• Lymph capillaries merge into larger lymph veins.

Lymphatic Drainage Pathways

8Lymphatic System Right Lymphatic Duct Thoracic Duct Lymphatic Vessels Spleen Lymph to Circulatory System Lymph Node Lymph From Limbs and Organs C. Lynn

• Lymph veins from the upper body drain into the Right Lymphatic Duct, which empties its contents into the Right Subclavian Vein.
• Lymph veins from the lower body drain into the Thoracic Duct, which empties into the Left Subclavian Vein.

Primary Lymphoid Organs

9Primary Lymphoid Organs

Thymus Gland Function

10Thymus Gland · Located over the heart. · T cells (Lymphocytes) mature in this gland and help with cell-mediated immunity. Thyroid Thymus Right lung Left lung

Red Bone Marrow Role

11Red Bone Marrow Contains stem cells that continually divide and differentiate into red and white blood cells and platelets.

12Most bones contain red marrow in children. In adults red marrow is found in: - skull - ribs - clavicle – sternum - pelvis - vertebral column Red Marrow Yellow Marrow Spongy bone Epiphysis Red marrow Yellow marrow Diaphysis Compact bone Epiphysis Infant <1 yr Adult 25+ yrs Left femur posterior view Left femur coronal section

Red and Yellow Marrow Conversion

13Red Marrow 1 Y Yellow Marrow Conversion begins at center Extends axially and peripherally Cartilage INFANT 0-1 years CHILD 1-10 years ADOLESCENT 10-20 years ADULT 20+ years

Secondary Lymphoid Organs

14Secondary Lymphoid Organs

Spleen Organ

15Spleen . An organ located behind the stomach on the left side of the body. . It contains white blood cells (macrophages) that destroy old and defective blood cells. · It acts as a blood reservoir in case blood pressure drops. Spleen Stomach

Lymph Nodes Structure

16Lymph Nodes · Small ovoid masses that are located alongside lymph vessels. . There are about 450 in the human body! · They range in size from 1mm to 2cm in size. · Nodes are clustered in: - groin - neck - armpits - behind the knees Lymph nodes Lymph vessels Lymph nodes Lymph vessels

Lymph Nodes Function

17· Lymph nodes house lymphocytes and also filter the debris, pathogens and damaged cells out of the lymph. · Several vessels bring lymph to the lymph node and one vessel carries it away. Swollen lymph nodes O MAYO FOUNDATION FOR MEDICAL EDUCATION AND RESEARCH. ALL RIGHTS RESERVED.

Lacteals in Small Intestine

18Lacteals · Lymph vessels in the villi of the small intestine through which fatty acids and glycerol are absorbed. Lacteal in Small Intestine Villus Villi Epithelium Lacteal Small intestine Blood capillaries Circulatory system Lymphatic system

Lipid Transport Pathway

19Lipids enter the circulatory system via the lymphatic circulation, so they don't directly go through the Hepatic Portal Vein like amino acids and glucose. Transport of lipids Left subclavian vein Villus (greatly enlarged) Chylomicron Heart Liver Blood capillary Hepatic portal vein K Lacteal Thoracic duct Amino acid Monosaccharide Venule 6 Arteriole Blood 1 Lymphatic vessel Lymph 20 Short chain fatty acidPalatine tonsil Submandibular node Cervical node Right internal jugular vein Right lymphatic duct Left internal jugular vein Thoracic duct Right subclavian vein Left subclavian vein Thymus Axillary node Lymphatic vessel Thoracic duct Spleen Cisterna chyli Small intestine Intestinal node Aggregated lymphatic follicle (Peyer's patch) Large intestine Iliac node Appendix - Inguinal node

Lymphatic System Overview

21LYMPHATIC SYSTEM 44 OVERVIEW OF THE LYMPHATIC SYSTEMInflammation skin Alila MEDICAL ME

Inflammatory Response Details

23Inflammatory Response Injury Inflammation Pain Warmth Swelling Redness Harmful things enter the body AboutKidsHealth ca 24