ANATOMY AND PHYSIOLOGY - Lymphatic System

Question 1

What are the four components of the lymphatic system?

Answer 1

Lymph
Lymphatic vessels
Lymphatic ducts
Lymphoid tissues

Question 2

What is the function of lymph?

Answer 2

Lymph is a watery liquid from the interstitial space that picks up fats, bacteria and other unwanted materials and filters these through the lymphatic system

Question 3

What is the function of the primary lymphoid tissues/organs?

Answer 3

Lymphocyte production

Question 4

What are the four primary lymphoid tissues/organs?

Answer 4

Bone marrow
Thymus
Foetal liver
Bursa of fabricus

Question 5

In which species is the Bursa of fabricus present in?

Answer 5

The Bursa of fabricus is only present in birds

Question 6

What is the function of the secondary lymphoid tissues/organs?

Answer 6

Lymphocyte activation

Question 7

What are the secondary lymphoid tissues/organs?

Answer 7

Lymph nodes
Spleen
Tonsils
Mucosa-associated lymphoid tissue (MALT)

Question 8

What are the two main functions of the lymphatic system?

Answer 8

Supports the cardiovascular system
Supports the immune system

Question 9

How does the lymphatic system support the cardiovascular system?

Answer 9

The lymphatic system maintains fluid levels through returning fluid to the bloodstream

Question 10

How does the lymphatic system support the immune system?

Answer 10

The lymphatic system filters out unwanted materials and is the site of lymphocyte production, maturation and activation

Question 11

How is fluid (lymph) returned back into the systemic circulation by the lymphatic system?

Answer 11

Hydrostatic pressure pushes fluid out of the capillaries into the interstitial space and oncotic pressure pushes fluid from the interstitial space into the capillaries. The excess fluid left in the interstitial space, known as lymph, is collected by lymphatic capillaries which merge to form lymphatic vessels which filter the lymph through lymph nodes before travelling towards the heart. Filtered lymph drains into lymphatic ducts and into the subclavian veins, back into the systemic circulation

Question 12

What are the two lymphatic ducts?

Answer 12

Right lymphatic duct
Thoracic lymphatic duct

Question 13

Which parts of the body are drained by the right lymphatic duct?

Answer 13

Right thoracic cavity
Right arm
Right side of the head and neck

Question 14

Which vein does the right lymphatic duct drain into?

Answer 14

Right subclavian vein

Question 15

Which parts of the body are drained by the thoracic lymphatic duct?

Answer 15

The thoracic lymphatic duct drains the areas of the body the right lymphatic duct does not

Question 16

Which vein does the thoracic lymphatic duct drain into?

Answer 16

Left subclavian vein

Question 17

Unlike blood vessels, lymphatic vessels have no pressure, so how does the lymph move around the body?

Answer 17

Contraction of skeletal muscle during movement
Contraction of smooth muscle in lymphatic vessel walls
System of valves preventing lymph back flow

Question 18

What are the specific functions of bone marrow in the lymphatic system?

Answer 18

Production and maturation of B-lymphocytes
Production of T-lymphocytes

Question 19

What are the specific functions of the thymus in the lymphatic system?

Answer 19

T-lymphocyte maturation and proliferation

Question 20

Where are the immature and mature T-lymphocytes found within the thymus?

Answer 20

The T-lymphocyte maturity increases from the cortex to the medulla of the thymus

Question 21

Where does lymph enter and exit lymph nodes?

Answer 21

Lymph enters via afferent lymphatic vessels and exits via efferent lymphatic vessels at the hilus of the lymph node

Question 22

Where are the germinal centres contained within follicles located within the lymph node?

Answer 22

Germinal centres contained within follicles are found within the cortex of the lymph node

Question 23

Where are B-lymphocytes found within lymph nodes?

Answer 23

B-lymphocytes are found within the lymphoid follicles

Question 24

What is the paracortical zone of the lymph nodes?

Answer 24

The paracortical zone is the area between the cortex and the medulla in the lymph nodes

Question 25

Where are T-lymphocytes found within lymph nodes?

Answer 25

T-lymphocytes are found within the paracortical zone

Question 26

What is the function high endothelial valves found in the lymph nodes?

Answer 26

High endothelial valves are modified post-capillary venues that enable lymphocytes in the blood to enter the lymph via diapedesis

Question 27

What are the two main tissue types found in the spleen?

Answer 27

White pulp
Red pulp

Question 28

What is the function of white pulp in the spleen?

Answer 28

White pulp is lymphoid tissue involved in immunosurveillance

Question 29

What is the function of red pulp in the spleen?

Answer 29

Red pulp contains venous sinuses (blood filled cavities) which are lined with macrophages to phagocytose any pathogens, foreign material or senescent erythrocytes and thrombocytes

Question 30

What are periarteriolar lymphoid sheaths (PALS) found in the spleen?

Answer 30

Periarteriolar lymphoid sheaths (PALS) are portions of white pulp surrounding the central arterioles running through the spleen

Question 31

What is the function of periarteriolar lymphoid sheaths (PALS) in the spleen?

Answer 31

Blood must pass through the periarteriolar lymphoid sheaths (PALS) and undergo immunosurveillance before entering the red pulp to be drain by the venous sinuses

Question 32

List three examples of MALT tissue

Answer 32

Peyer’s patches
Gut-associated lymphoid tissue (GALT)
Bronchial-associated lymphoid tissue (BALT)