Lymphatics

Question 1

What three things make up the lymphatic system?

Answer 1

Lymph nodes, lymph fluid, drainage vessels

Question 2

How is tissue fluid formed

Answer 2

High hydrostatic pressure in the capillary (lower oncotic) pushes fluid into the interstitium. High oncotic pressure in the interstitium (lower hydrostatic) pushes fluid back into capillary venule. Remaining tissue fluid -> lymph capillary

Net filtration not equal to net reabsorption (leakage of some smaller proteins, bacteria, debris etc into interstitium)

Question 3

What is lymph made of?

Answer 3

Tissue fluid, small proteins, lipids, damages cells, bacteria, cancer cells

Question 4

How much lymph does the body produce daily?

Answer 4

3-4L

Question 5

Define what the lymphatic system does.

Answer 5

Continuous removal of remaining tissue fluid from EC space back to circulation. Route for spread of infection and malignancy

Question 6

What are the 3 main roles of the lymph system?

Answer 6

Remove excess fluid from interstitium, return leaked small proteins and fluid to capillaries, immune defect- surveillance and phagocytic barrier

Question 7

How many nodes must lymph pass through?

Answer 7

At least one

Question 8

What two features make flow one directional?

Answer 8

Passive constriction- as get bigger run alongside pulsating arteries.
Intrinsic constriction- intrinsic ability to contract as start to fill with fluid (SM cells in larger vessels)

Question 9

What are the two main lymphatic ducts everything drains into? Where do these drain?

Answer 9

R lymphatic duct and thoracic duct (L). Drain into subclavian

Question 10

What does the R lymphatic duct drains?

Answer 10

R side of face, R arm, R hemithroax

Question 11

What does the throacic duct drain?

Answer 11

L side of face, L hemithroax, abdomen and rest of body

Question 12

Why does lymph not drain into arteries?

Answer 12

High pressure c.f veins that are low- draining low pressure to low pressure

Question 13

What is lymphoedema?

Answer 13

Abnormal collection of protein rich fluid -> tissue swelling due to compromised lymp system. Non-pitting oedema. Chronic condition

Question 14

What are the causes of lympoedema?

Answer 14

• Removed/enlarged nodes
• Infections (parasitic)
• Damage e.g cancer treatments
• Lack of limb movement- muscle constriction for movement of lymph
• Congenital- Milroy’s syndrome

Question 15

What are the three main lymphoid organs?

Answer 15

Spleen, thymus, tonsils

Question 16

What is the structure of a lymph node? Size? What do they contain?

Answer 16

CT, tough fibrous outer capsule, reticular CT indies (candy floss). Microscopic ->2.5cm. Collection of B and T lymphocytes

Question 17

What are the two causes of swollen lymph nodes and the characteristics of each?

Answer 17

Infection (tender, mobile) e.g HIV, TB.

Malignancy (hard, matted, non-tender)

Question 18

Where do regional nodes drain?

Answer 18

Into terminal nodes

Question 19

800 lymph nodes in the body, how many in the H and N?

Answer 19

300

Question 20

What are sup (regional) and deep (terminal) lymph nodes separated by?

Answer 20

Investing layer of deep cervical fascia

Question 21

Name the sup lymph nodes

Answer 21

Submental, submandibular, pre-auricular, post-auricular, occipital, superficial cervical

Question 22

What is Walderyer’s Ring and what does it consist of?

Answer 22

Collection of lymph nodes surrounding sup pharynx.
Pharyngeal tonsils (adenoids), 2 palatine, 2 lingual

Question 23

What are the 3 deep cervical lymph nodes? Which is most commonly enlarged, why?

Answer 23

Jugular-digastric, jugular-omohyoid, suprclavicular. Jugular-digastric- drains palatine tonsil- tonsillitis. (Also drains oral cavity, post 1/3 tongue, pharynx and larynx

Question 24

What is the importance of the L suprclavicular node?

Answer 24

Virchow’s node- pancoast apical lung tumour.

Question 25

What does the submandibular node drain?

Answer 25

Most of face, upper lip and teeth, lat lower lip, ant nasal cavity, middle tongue, submandibular and sublingual glands

Question 26

What does the submental node drain?

Answer 26

Lower lip and teeth, ant chin, tip of tongue, floor of mouth

Question 27

What do sup cervical lymph nodes drains?

Answer 27

Skin of neck

Question 28

What does the occipital node drains?

Answer 28

Occipital area of neck and scalp

Question 29

What does the pre auricular node drain?

Answer 29

Scalp, ant ear, parotid gland

Question 30

What does the post auricular node drain?

Answer 30

Scalp, post ear, ear canal

Question 31

Which tonsil is enlarged in tonsillitis?

Answer 31

Palatine