5) Lymphatic Drainage

Question 1

What does the lymphatic system consist of?

Answer 1

Lymph nodes
Lymphoid organs - spleen, thymus, tonsils
Drainage vessels
Lymph (fluid)

Question 2

Where is the lymphatic system absent?

Answer 2

Eyeball, inner ear and cartilage

Question 3

Describe the formation of lymph:

Answer 3

Tissue fluid forced out of capillary due to high hydrostatic pressure. Not all tissue fluid is reabsorbed and remaining fluid moving into lymph vessels is called lymph

Question 4

What does lymph consist of?

Answer 4

Tissue fluid, small proteins, lipids, damaged cells, bacteria (+cancer cells)

Question 5

How much lymphatic fluid is produced per day?

Answer 5

3-4L

Question 6

What are the features of lymphatic flow?

Answer 6

Unidirectional, low pressure and no central pump

Question 7

Describe lymphatic flow from capillaries to ducts:

Answer 7

Lymph capillaries -> lymph vessels (afferent) -> node -> efferent vessel (one) -> lymphatic trunks -> lymphatic ducts

Question 8

What causes lymph flow to remain unidirectional?

Answer 8

Unidirectional drainage at capillary
Valves so no backflow
Passive constriction due to pulsation of artery or muscle contraction
Intrinsic constriction by SMCs

Question 9

Where does the lymph system drain into?

Answer 9

Subclavian veins

Question 10

Which duct drains more lymph?

Answer 10

Left (thoracic) duct

Question 11

What is lymphoedema?

Answer 11

Abnormal collection of protein-rich fluid causing tissue swelling due to compromised lymphatic system

Question 12

What are some causes of lymphoedema?

Answer 12

Removal/enlargement of LNs (after cancer treatment)
Infections 
Damage to lymph system 
Lack of limb movement 
Congenital e.g. McIlroy's

Question 13

Name a cause of pitting and non-pitting oedema:

Answer 13

Pitting - heart failure

Non-pitting - lymphoedema

Question 14

What are lymph nodes?

Answer 14

Connective tissue structures with tough outer capsule and reticular CT inside

Question 15

What are contained within lymph nodes?

Answer 15

Large collections of lymphocytes and macrophages

Question 16

What is the clinical term used to describe swollen lymph nodes?

Answer 16

Lymphadenopathy

Question 17

What causes swollen LNs?

Answer 17

Infection

Malignancy

Question 18

How can lymph nodes be classified?

Answer 18

Regional - superficial, draining specific area

Terminal - deep

Question 19

Where can lymph nodes be palpated?

Answer 19

Neck (cervical)
Armpit (axillary)
Diaphragm 
Spleen
Abdominal 
Pelvic
Groin

Question 20

What are cervical regional and terminal lymph nodes separated by?

Answer 20

Investing layer of deep cervical fascia

Question 21

Give examples of the superficial cervical lymph nodes:

Answer 21

Submental, submandibular, pre and post auricular, occipital, superficial cervical, anterior cervical and posterior cervical

Question 22

What is Waldeyer’s ring?

Answer 22

Annular collection of lymphatic tissues (nodules) surrounding superior pharynx
Pharyngeal tonsil, 2 palantine tonsils and 2 lingual tonsils

Question 23

What are the names of the deep cervical lymph nodes?

Answer 23

Jugulo-digastric, jugulo-omohyoid and supra-clavicular

Question 24

What does the jugulo-digastric LN drain?

Answer 24

Behind mandible and drains palatine tonsil and tongue

Swollen in tonsillitis

Question 25

What does the jugulo-omohyoid LN drain?

Answer 25

Drains tongue, oral cavity, trachea, oesophagus and thyroid

Question 26

What does the supra-clavicular LN drain?

Answer 26

Thoracic cavity and abdomen

Question 27

What are important signs seen in supra-clavicular LNs?

Answer 27

Both on left:
Virchow’s - abdomen and thorax malignancy
Trosier’s sign - metastatic abdominal malignancy

Question 28

What do swollen LNs caused by infection feel like?

Answer 28

Tender and mobile

Question 29

What do swollen LNs caused by malignancy feel like?

Answer 29

Hard, matted and non-tender