The Lymphatic System

Question 1

What are the functions of the lymphatic system?

Answer 1

• tissue drainage
• return of plasma and plasma proteins
• absorbed fat transport from gut
• immunity

Question 2

What are the constituents of the lymphatic system?

Answer 2

• lymphatic vessels (differ from blood vessels in that they absorb proteins and other large molecules from tissue fluid)
• lymphatic tissues (thymus, spleen, tonsils, nodules)

Question 3

What volume of proteins and plasma proteins is returned by the lymphatic system each day?

Answer 3

8L

Question 4

What is the composition of the lymphatic system?

Answer 4

• lymph is a fluid containing plasma proteins
• it gains lymphocytes as it flows through lymphatic capillaries/ channels
• it gains fats in the small intestine

Question 5

What does lymphatic flow rely on? (same as blood vessels)

Answer 5

• muscle contraction
• pressure changes
• gravity
• unidirectional because of valves

Question 6

How does flow vary during infection?

Answer 6

• flow into extracellular spaces increases during infection due to protein accumulation and osmosis
• this drive increases lymph flow and therefore immune response in nodes, as more antigens are presented and phagocytosis occurs

Question 7

What are lymph nodes?

Answer 7

• secondary lymphoid tissue periodically traversed by lymphatic vessels
• where the immunological function of lymph are located
• they can be isolated or grouped

Question 8

Are lymph nodes isolated or grouped?

Answer 8

They can be both

Question 9

How many lymph nodes are there in a young adult?

Answer 9

About 450

Question 10

What does efferent lymph contain more off?

Answer 10

It is filtered and therefore contains more antibodies

Question 11

What happens to inert particles in the blood stream?

Answer 11

• they are filtered out in the lymph nodes (ex: carbon particles or tattoo pigments)

Question 12

What routes does the lymphatic system follow?

Answer 12

• follows deep arteries in cavities
• follows superficial veins in superficial parts of limbs
• follows deep arteries and veins in deep parts of limbs

Question 13

Which part of the body has no lymphatic drainage routes?

Answer 13

• eyeball
• CNS
• inner ear
• epidermis
• cartilage
• bone
• majority of spleen and liver

Question 14

Where are the superficial lymph nodes situated?

Answer 14

• in and around the femoral triangle at the base of the lower limb

Question 15

Which localised part of the body contains 50% of the body’s nodes?

Answer 15

• abdomen, pelvis and gut

Question 16

What pathologies affect lymph nodes?

Answer 16

• primary tumours (lymphomas) such as Hodgkins
• secondary tumours as a result of metastasis from other sites
• infection such as tuberculosis and glandular fever (mononucleosis)
• inflammatory hyperplasia

Question 17

What is the lymphatic system’s drainage routes throughout the whole body?

Answer 17

• initial symmetry from limbs, head, neck and trunk
• ultimately all lymph congregates into 2 large lymph ducts
• these empty into the venous system at the jugular/ subclavian junction

Question 18

Where does the fat drained from the small intestine go?

Answer 18

• drained to the superior vena cava and eventually to the liver

Question 19

Where are lymphocytes generated and where do they mature?

Answer 19

• thymus and bone marrow
• spleen
• lymph nodes
• peyer’s patch
• tonsils
• lymphocytes

Question 20

What is the spleen?

Answer 20

• largest lymphatic organ
• upper left quadrant of abdomen (peritonised)
• contains large amount of blood, routinely discharged via smooth muscle action