Lymphatic System

Question 1

lymphatic system

Answer 1

The lymphatic system is an extensive network of 
vessels and nodes that collects lymph from the 
spaces between the cells and empties it into the 

venous circulation just before it enters the heart.

Question 2

lymph nodes

Answer 2

The lymph nodes protect the body 
against infection. important sites of lymphocyte 

formation. Lymphocytes are the white blood cells that 

manufacture antibodies, and during periods of active 

antibody formation the lymph nodes often become 

swollen and tender. only occur in mammals

Question 3

lymph vessels

Answer 3

Lymph vessels are found in all vertebrate. In most 
amphibians and reptiles and in some fishes, the lymph is 
propelled by pulsating lymph hearts. In other vertebrates, 
including all mammals, lymph movement depends primarily 
on external forces, such as the action of neighboring skeletal 

muscles, pulsations of nearby arteries, intestinal 

contractions, alterations of pressure within the chest during 
breathing, and the force of gravity.

Question 4

things to remember

Answer 4

• remember: closed circulatory system in mammals
• diameter of blood and lymph capillaries is large enough to allow passage of blood cells
• lymph vessels are closed tubes (one way flow)

Question 5

water potential

Answer 5

Water potential is the net effect of osmotic pressure and physical pressure on water movement