Exercise 10

Question 1

What are the three main functions of the lymphatic system in maintaining homeostasis?

Answer 1

2.​The three main functions of the lymphatic system in maintaining homeostasis are:
​i) lymphatic capillaries take up excess tissue fluid and return it to the blood.
​ii) lacteals found within the villi of the small intestine, pick up lipoproteins (fat molecules) and bring them to the blood.
​iii)the lymphatic system helps defend the body against disease (pathogens)

Question 2

What is the name of the fluid that is carried by the lymphatic vessels, and what is its composition similar to?

Answer 2

The fluid carried by the lymphatic system is called lymph which has the same composition as tissue fluid.

Question 3

Which set of capillaries is responsible for taking up excess tissue fluid; blood capillaries or lymph capillaries?

Answer 3

​Lymphatic capillaries are responsible for taking up excess tissue fluid that contains water and excess solutes that have come from the blood capillaries.

Question 4

How are lymph capillaries different from blood capillaries?

Answer 4

Lymphatic capillaries unlike blood capillaries are closed-ended making the lymphatic system a one-way system not a continuous circuit.

Question 5

Briefly describe the structure of the larger lymphatic vessels.

Answer 5

The larger lymphatic vessels are similar in structure to veins: movement within these vessels is dependent upon skeletal muscle and respiratory movements and valves prevent back flow.

Question 6

What are the two lymphatic ducts and what is their purpose?

Answer 6

The two lymphatic ducts (tubes) are the thoracic duct and the right lymphatic duct. The lymphatic ducts collect lymph and deliver it to the subclavian veins of the cardiovascular system.

Question 7

Where are lymph nodes found? What do lymph nodes contain and what is their function?

Answer 7

8.​Lymph nodes are found along the larger lymphatic vessels. Their function is to filter lymph and they do this with the help of lymphocytes and macrophages.

Question 8

Where is the spleen located? What is its size and how does it function?

Answer 8

The spleen is located in the upper left region of the abdominal cavity just beneath the diaphragm and behind the stomach. The spleen is about the size of a fist and like lymph nodes it contains lymphocytes and macrophages. Its function is to cleanse the blood of debris and pathogens, while the function of the lymph nodes is to clean the lymph.

Question 9

What does the lymphatic system consist of?

Answer 9

The lymphatic system consists of lymphatic vessels and the lymphatic organs.