The Lymphatic System Flashcards
What does the Lymphatic System Consist of?
- Lymph Fluid
- Lymphatic Vessels
- Lymphatic Organs
What are the Lymphatic Organs?
- Red Bone Marrow
- Thymus
- Lymph Nodes (L.N.)
- Tonsils
- Spleen
What are the main functions of the Lymphatic System?
- Drains Excess Interstitial Fluid
- Transports Dietary Lipids
- Filters Lymph and Blood
- Carries Out Immunological Responses
Describe the look of the Lymph in the Lymphatic System?
- Clear
- Transparent
- Slightly Yellowish Fluid
What is the Structure of the Lymph?
- Resembles Blood Plasma but more dilute
How is Lymph Formed?
- Starts in the blood capillary network
- Plasma and nutrients diffuse into the interstitial tissue from the arterial capillaries to supply the target organ
- 85% of that interstitial fluid after exchanging nutrients goes back into venous capillaries
- 15% of the interstitial fluid enter the lymphatic vessels
What do the Lymphatic Capillaries do?
- Collect the remnants of the interstitial fluid
- Remove cell debrides and waste metabolic by-products from different tissues except the nervous system.
- Removes pathogens
- Receives dietary lipids from GI system and lymphocytes from blood
Describe the formation of Lymph Ducts?
- Lymphatic Vessels join to form the Lymph Trunks
- Lymph Trunks unite to form Lymph Ducts
Where do the Lymph Ducts drain?
- Into the Venous System
What are the Junctions between the Lymph Ducts and Venous System?
- Subclavian
- Internal Jugular Veins
What is the structure of the Lymph Nodes?
- Small Kidney shape, around 2 inches
What are the Lymph Nodes?
- The Site of the lymph filtration
- Site of B Lymphocytes Proliferation
How are Lymph Nodes Named? What are the main ones?
Named - The region they are found Main Ones - Cervical LN - Axillary LN - Lumbar LN - Inguinal LN
What do the Cervical Lymph Nodes accompany?
- Larger Venous System
Where are the Axillary Lymph Nodes?
- Around the Axillary Vein
Where are the Lumbar Lymph Nodes?
- Close to the post abdominal wall and vertebrae
What is the difference between the Afferent and Efferent Lymphatic Vessels?
- Afferent: they enter the lymph nodes
- Efferent: they leave the lymph nodes
What happens to the Lymph that is circulating in the Lymph Nodes?
- Monitored and Filtered
What is the structure of the Thymus?
- Anterior and Superior Mediastina, in front of the Fibrous Pericardium
- Two Lobes: Right and Left, 30-40 grams
What is the Function of the Thymus?
- Maturation of the T-Cells that are born in the bone marrow
What happens to the immature T-Cells?
- 2% turn into mature active ones
- 98% are digested by macrophages