The Lymphatic System

Question 1

What are lacteals?

Answer 1

The lymphatic vessels of the small intestine which absorb digested fats

Question 2

What is chyle?

Answer 2

A milky fluid containing fat droplets which drains from the lacteals of the small intestine into the lymphatic system during digestion

Question 3

Name four lymphatic ducts in the body

Answer 3

Right lymphatic duct, thoracic duct, right subclavian duct and lumbar trunks

Question 4

Describe the right lymphatic duct?

Answer 4

This drains the right upper quadrant of the body including the right side of the head, neck, thorax and right arm. This duct drains into the right subclavian vein at the junction with the internal jugular vein (the right venous angle)

Question 5

Describe the thoracic duct?

Answer 5

This duct drains the rest of the body apart from the right upper quadrant and it begins in the abdomen as the cisterna chyle and drains at the left venous angle (Virschow’s node)

Question 6

What structures drain their fluid into the cervical lymph nodes?

Answer 6

Fluid from the skin above the clavicle

Question 7

What structures drain their fluid into the axillary lymph nodes?

Answer 7

Fluid from the skin between the clavicle and umbilicus

Question 8

What structures drain their fluid into the inguinal lymph nodes

Answer 8

Fluid from the skin below the umbilicus

Question 9

What is the role of superficial lymph nodes? Name three.

Answer 9

To drain the fluid from the skin. Examples are cervical, axillary and inguinal lymph nodes.

Question 10

Describe the lymphatic drainage of the head and neck

Answer 10

Some fluid enters the superior cervical lymph nodes, others drain into the deep cervical lymph nodes

Question 11

Describe the horizontal inguinal lymph nodes

Answer 11

These are superficial and run on top of the inguinal ligament; they drain fluid from the anterior abdominal wall, perineum and external genitalia apart from the testes

Question 12

Describe the vertical inguinal lymph nodes

Answer 12

These lie at the termination of the greater saphenous vein in the leg, and provides most of the superficial lymphatics of the leg

Question 13

What is the lymphatic drainage of the abdomen and the lower limb

Answer 13

To the horizontal and vertical inguinal lymph nodes

Question 14

Describe the lymphatic drainage of the posterior abdominal wall

Answer 14

To the lumbar lymph nodes, pre-aortic lymph nodes and the intestinal lymphatic trunk

Question 15

Where are the lumbar lymph nodes located?

Answer 15

On the external and internal iliac arteries

Question 16

Where are the pre-aortic lymph nodes and intestinal lymphatic trunk located?

Answer 16

On the abdominal blood vessels

Question 17

Where is the cisterna chyle found?

Answer 17

This is the beginning of the thoracic duct and it is found anterior to L1/L2 vertebra

Question 18

What structures drain into the cisterna chyle?

Answer 18

Intestinal, right and left lumbar trunks

Question 19

What is the function of the lymphatic system?

Answer 19

It drains excess fluid and leaked plasma proteins and provides defence against pathogens (antibodies and phagocytosis)

Question 20

How does fluid drain into the lymphatic vessels?

Answer 20

When the pressure in the tissue fluid is high, this causes the endothelial cells of the lymphatic vessels to be opened, allowing entry of the excess fluid (and proteins – large gaps, highly permeable). The collagen fibres allow the valves to open without collapse, but the valves (endothelial cells) close when the pressure within the lymphatic vessel itself is high.

Question 21

How is lymph transported around the body?

Answer 21

Travel in low-pressure conduits, so active skeletal muscle is required for movement in addition to valves and pressure changes int he thorax.

Question 22

Name the lymph nodes of the head and neck that are palpable

Answer 22

• Preauricular
• Postauricular
• Occipital
• Submandibular
• Submental
• Superficial anterior cervical
• Deep cervical
• Posterior cervical
• Supraclavicular

Question 23

Name four palpable lymph nodes of the axilla

Answer 23

o Anterior axillary (pectoral)
o Lateral (brachial)
o Mid axillary (central)
o Posterior (subscapular)

Question 24

Name the palpable lymph nodes of the legs

Answer 24

• Superficial superior inguinal
• Superficial inferior inguinal
• Popliteal (occasionally)

Question 25

Outline the role of the spleen as a lymphoid organ

Answer 25

Provides site for the proliferation of lymphocytes, extracts aged blood cells, stores and secretes bilirubin

Question 26

Outline the role of the thymus as a lymphoid organ

Answer 26

Secretes thymopoietin and thymosins which cause T lymphocytes to mature (become immunocompetent)

Question 27

Outline the role of the tonsils as a lymphoid tissue

Answer 27

Gather and remove some pathogens which enter the pharynx in food or inhaled air.

Question 28

Outline the role of Peyer’s patches as lymphoid tissue

Answer 28

These are isolated clusters of lymphoid tissue located in the ileum (also concentrated lymphoid follicles in the appendix. These patches work to destroy bacteria so that they do not breach the intestinal wall as well as to develop memory/adaptive immunity.

Question 29

What is Virchow’s node and what is it’s clinical significance?

Answer 29

This is the left venous angle and palpable nodes here may be indicative of metastatic cancer in the liver and/or lungs

Question 30

Describe the course of the superficial cervical lymph nodes.

Answer 30

They run alongside the external jugular vein over the SCM muscle

Question 31

Describe the course of the deep cervical lymph nodes.

Answer 31

These travel in the vertical chain along the internal jugular vein

Question 32

Where are Peyer’s patches found?

Answer 32

In the ileum