Lymphatic System

Question 1

What is the lymphatic system

Answer 1

• It’s a second circulatory system
• It’s a one way system
• Lymph- vessels collect any fluid surrounding the body’s cells and returns it to the blood

Question 2

What is the structure of the lymphatic system

Answer 2

Consists of lymph nodes, lymph vessels, tonsils, spleen and thymus gland

Question 3

Organs located in the lymphatic system

Answer 3

• Tonsils
• Spleen
• Thymus gland

Question 4

What are lymph nodes

Answer 4

• Lymph nodes are swelling in the lymph vessels
• Found in clusters(glands) in the tonsils, neck, armpit, spleen and groin

Question 5

How do lymph nodes fight infection

Answer 5

• They fight infection by the nodes filtering bacteria
• Contain large amounts of lymphocytes(produce antibodies)(white blood cells)

Question 6

How does lymph fluid form?

Answer 6

• Arteries contain blood that has higher blood pressure than veins
• This forces out some fluid and small proteins out of the capillaries in the arteriole side(tissue fluid)
• Tissue fluid surrounds all the cells of the body and helps with exchanging substances in and out of the cells
• Tissue fluid is formed at a rate of 1 litre per hour. To prevent swelling it is removed and returned to the blood

Question 7

How does tissue fluid differ from plasma

Answer 7

• Tissue fluid does not have platelets or red blood cells or clotting proteins but blood does

Question 8

How is tissue fluid removed

Answer 8

• 10% of the tissue fluid enters lymph vessels(referred to as lymph)
• 90% of tissue fluid is returned back into the plasma in the capillaries(occurs by osmosis) and is helped by the reduced blood pressure in the veins

Question 9

What does lymph fluid contain

Answer 9

• White blood cells
• Proteins
• Higher levels of fats

Question 10

Is lymph fluid under high or low blood pressure

Answer 10

Low blood pressure

Question 11

So how is lymph moved slowly through the lymph vessels

Answer 11

• Physical activity squeezes(presses) on the vessels
• Valves prevent lymph fluid flowing backwards

Question 12

What are the two main lymph vessels

Answer 12

1. The thoracic duct(left side of body)
2. Right lymphatic duct(right side of body)

Question 13

Where is the lymph fluid emptied

Answer 13

Lymph fluid in the ducts is emptied into the blood at the Subclavian veins which is located near the collar bone

Question 14

Functions of the lymphatic system

Answer 14

1. To absorb fats from the digestive system into the lacteal. These fats are transported in the lymph vessels of the lymphatic system(lymph is found in the lacteals in villi)
2. To collect tissue fluid and return it to the blood
3. To defend the body against infections
   - Lymph nodes filtering harmful bacteria
   - Stores and matures lymphocytes which produce antibodies that neutralise foreign substances