Lymph, lymphatics, and lymphatic movement

Question 1

What is lymph?

Answer 1

Lymph is the nearly colorless watery fluid in the lymphatic system.

Lymph, or lymphatic fluid, is made from interstitial fluid or fluid found between cells and tissues.

Question 2

What is the composition of lymph?

Answer 2

The composition of lymph continually changes as blood and surrounding cells continually exchange substances with the interstitial fluid.

Lymph, interstitial fluid, and plasma are basically the same fluid but called different names depending on where it is located.

Question 3

How is lymph formed?

Answer 3

When interstitial fluid enters lymphatic capillaries, it is called lymph. After lymph is filtered by lymph nodes, it is returned to the blood, becoming plasma once again.

Lymph is formed from interstitial fluid.

Question 4

What are lymphatics?

Answer 4

Lymphatics are all the lymphatic capillaries, vessels, trunks, and ducts along the lymphatic chain

Lymphatics are the network of vessels responsible for the transport of lymph.

Question 5

Where does lymph flow through and enter the cardiovascular system?

Answer 5

Lymph flows through lymphatics and enters the cardiovascular system at the right and left subclavian veins.

The subclavian veins are the main veins in the upper body that receive lymphatic fluid.

Question 6

Which organ of the body does not have a rich supply of lymphatics?

Answer 6

With exception of the central nervous system, every organ of the body has a rich supply of lymphatics.

The central nervous system is an exception to the presence of lymphatics in every organ.

Question 7

Where do lymph capillaries begin?

Answer 7

Lymph capillaries begin in the spaces between the tissues as close-ended sacs.

No additional information.

Question 8

How do lymph capillaries compare in diameter to blood capillaries?

Answer 8

Lymph capillaries are slightly larger in diameter compared with blood capillaries.

No additional information.

Question 9

What do the walls of lymph capillaries overlap to form?

Answer 9

The walls of lymph capillaries overlap to form a flapped one-way valve.

No additional information.

Question 10

What are anchoring fibers attached to lymph capillaries for?

Answer 10

Attached to lymph capillaries are anchoring fibers, which secure the capillary to surrounding tissues. When tissues expand because of excess interstitial fluid, anchoring fibers become stretched, causing the flap to pull apart and open. This action allows surrounding interstitial fluid to enter the lymph capillary. When pressure inside the lymph capillary is greater compared with the surrounding tissues, the flap closes, preventing lymph from moving back into the interstitial spaces.

No additional information.

Question 11

What are lacteals?

Answer 11

Lacteals are lymphatic capillaries in fingerlike projections of the small intestines. Lacteals absorb dietary fats and fat-soluble vitamins.

No additional information.

Question 12

What do lymph capillaries merge with?

Answer 12

Lymphatic vessels

Fig. 27.3 shows lymph in the capillary moving toward the center of the body.

Question 13

What do lymphatic vessels contain?

Answer 13

Internal valves that open in only one direction

There are more valves in lymph vessels compared with veins.

Question 14

Where do lymphatic vessels merge with?

Answer 14

Larger structures called lymphatic trunks

Lymphatic trunks drain larger regions of the body.

Question 15

How many lymphatic ducts does lymph move into?

Answer 15

Two lymphatic ducts: right lymphatic duct and the thoracic duct

The distribution of lymphatics progresses from smaller twigs to larger trunks.

Question 16

What does the right lymphatic duct drain?

Answer 16

Lymph from the right side of the head and neck, right upper extremity, and right half of the upper trunk

The right lymphatic duct delivers lymph to the right subclavian vein.

Question 17

What does the thoracic duct drain?

Answer 17

Lymph from the rest of the body

The thoracic duct delivers lymph to the left subclavian vein.

Question 18

What is lymphokinesis?

Answer 18

The movement of lymph through the body.

Question 19

How does lymph movement differ from blood movement?

Answer 19

Lymph does not move in a circle and flows in one direction toward two collecting ducts.

Question 20

What may cause swelling by interfering with the flow of lymph?

Answer 20

An obstruction.

Question 21

How does lymph move through the body?

Answer 21

Lymph moves by the milking action of skeletal muscles, pressure differences between the thoracic and abdominal cavities, contraction and relaxation of smooth muscles within lymphatic walls, presence of valves, and compressive forces.