Lymphatic System

Question 0

Lymphatic capillaries

Answer 0

• network of tiny dead-end tubes throughout tissues
• end of tube is one cell thick & cells are arranged in a slightly overlapping pattern
• pressure from fluid allows fluid to enter but not leave
• one-way valves within lymph capillaries
• keeps flow of lymph away from tissues
• lymph capillaries meld together to form lymph vessels
• lymph vessels merge before flowing into 1 of 2 major ducts in body: r lymphatic duct & thoracic duct

Question 1

Lymphatic vessels

Answer 1

• parallel circulatory system

- have valves & rely on skeletal muscle contractions for flow

Question 2

Right lymphatic duct

Answer 2

Drains upper right body into right subclavian vein

Question 3

Thoracic duct

Answer 3

Drains rest of body into left subclavian vein

Question 4

Lymphoid organs

Answer 4

• lymph nodes
• tonsils
• spleen
• adenoids
• payers patches (groups of lymph tissue in small intestine)
• thymus gland
• red bone marrow

Question 5

Lymph nodes

Answer 5

• small round structures located along lymph vessels
• trap and filter bacteria and cell debris
• contain many WBC’s to fight inflection

Question 6

Removing excess fluid

Answer 6

• 90% of interstitial fluid is retuned to blood at capillary bed
• 10% accumulates in tissue fluid
• lymph capillaries absorb excess fluid
• fluid is processed by lymph nodes then returned to circulatory system
• fluid in lymphatic system = lymph

Question 7

Fatty acid transport

Answer 7

• fats digested in small int are passed from lacteals in villi to lymphatic system, then transported to blood via thoracic duct
• enriched lymph in small int = chyle

Question 8

Immune response - lymph organs

Answer 8

• adenoids & tonsils help fight infection
• spleen produces leukocytes and removes RBC’s
• thymus gland: leukocyte maturation

Question 9

Infection fighting

Answer 9

• some WBC’s phagocytize bacteria
• others form antibodies (proteins that attack based on shape)
• antigen: protein & carbs foreign to the body (ex. Virus, pollen, mold)
• specific lock and key recognition
• spleen fights infection using lymphocytes and WBC’s called macrophages which engulf and destroy bacteria, dead tissue, and foreign matter, then remove them from blood passing through spleen