Oro-facial lymphatics

Question 1

The lymphatic system consists of 4 components. What are these components?

Answer 1

1. organs (bone marrow, spleen and thymus)
2. lymphatic vessels (e.g. thoracic duct)
3. lymph nodes
4. mucosa-associated lymphoid tissue (MALT eg “tonsils”)

Question 2

What are the 3 functions of the lymphatic system?

Answer 2

1. Removes excess fluid (interstitial/tissue fluid) from the tissues of the body and returns it (as lymph) to the venous system.
2. Carries fats from the GI tract to the venous system.
3. Produces immune cells (lymphocytes, plasma cells & monocytes) in the defence against infection and cancer.

Question 3

What is the difference between tissue fluid and lymph?

Answer 3

Tissue fluid and lymph are essentially the same thing; however lymph is the name of tissue fluid when taken up into a lymphatic vessel.

Question 4

In the lymphatic system, where does the arterial blood head?

Answer 4

Towards the capillary bed

Question 5

In the lymphatic system, what happens to the deoxygenated blood?

Answer 5

It is taken away from the capillary bed

Question 6

What do lymph nodes contain?

Answer 6

Lymphocytes and macrophages.

Question 7

What is the major lymphatic vessel in the body responsible for?

Answer 7

It’s responsible for returning lymph to large veins in the neck.

Question 8

Where does the thoracic duct drain into?

Answer 8

The left venous angle

Question 9

What makes up the venous angle?

Answer 9

Internal jugular vein and subclavian vein

Question 10

Approximately how much tissue fluid is reabsorbed (taken back into capillary) daily?

Answer 10

16 - 18 litres

Question 11

Approximately, how much lymph is produced daily and returned to blood at venous angles?

Answer 11

2 - 4 litres

Question 12

Approximately how much lymph is produced daily in the head and neck?

Answer 12

400ml

Question 13

What is Elephantiasis?

Answer 13

Elephantiasis is the accumulation of a fluid called lymph in the affected areas.

Question 14

What is Elephantiasis caused by?

Answer 14

Elephantiasis is caused by obstruction of the lymphatic system.

Question 15

What is Oedema?

Answer 15

Excess / abnormal collection of fluid in tissues.

Question 16

What happens to all of the lymph as it is passed through the lymph nodes?

Answer 16

It is filtered.

Question 17

What is lymph screened for?

Answer 17

Lymph is screened for infectious agents and cancer cells by the lymphocytes and macrophages in the lymph nodes

Question 18

What happens to the lymph node as a result of it attempting to fight against an infection in the lymph?

Answer 18

It produces germinal centres, enlarges and becomes painful due to its capsule stretching

Question 19

A secondary tumour may grow in the node. What is the name of the development of this tumour?

Answer 19

Metastasis.

Question 20

Which group of nodes are the first to receive lymph from any given structure/area?

Answer 20

Regional lymph nodes (eg. tip of tongue)

Question 21

The lymph nodes of the head and neck are described in 2 groups; name these two groups.

Answer 21

1. The superficial ring

2. The deep cervical nodes.

Question 22

Where is the superficial ring group located?

Answer 22

The superficial ring group of nodes are located superficially- you can palpate these lymph nodes.

Question 23

Where are the deep cervical nodes located?

Answer 23

The deep cervical nodes are located deep to sternocleidomastoid muscle- these nodes are not directly palpable.

Question 24

How would you describe the orientation of the Superficial Ring of Regional Lymph Nodes?

Answer 24

They are arranged in a scarf- like orientation.

Question 25

What structures are drained in the lymphatic drainage of superficial structures of the head & neck?

Answer 25

Scalp, face, superficial upper neck

Question 26

What 7 nodes are associated with the superficial ring of regional lymph nodes?

Answer 26

1. occipital nodes 2. mastoid nodes 3. superficial cervical nodes 4. parotid nodes 5. buccal nodes 6. submental nodes 7. submandibular nodes

Question 27

What do the superficial cervical nodes accompany? Where is this situated?

Answer 27

They accompany the external jugular vein, and are situated on top of sternocleidomastoid.

Question 28

What do the deep cervical lymph nodes accompany? Where is this situated?

Answer 28

Deep cervical lymph nodes accompany internal jugular vein and are located deep to the sternocleidomastoid-opposite to superficial cervical lymph nodes

Question 29

What nodes are associated with the deep cervical nodes?

Answer 29

1. retro-pharyngeal nodes 2. submental nodes 3. submandibular note: submental and submandibular nodes cross both superficial and deep.

Question 30

What are the 5 kinds of tonsils and where are they found?

Answer 30

1. palatine tonsil “tonsil”: found in oropharynx 2. “palate associated lymphoid tissue” 3. pharyngeal tonsil “adenoid”: found in nasopharynx 4. tubal tonsil: found in nasopharynx 5. lingual tonsil: found in oropharynx

Question 31

As tonsils are the first site of encounter with inhaled and ingested micro-organisms, what are they considered as?

Answer 31

They are considered as the first line of defence against exogenous aggressors.

Question 32

The generation of __________ in the germinal centres of the tonsil is one of the most essential tonsillar functions.

Answer 32

B cells.

Question 33

What is the ring of tonsil/lymphoid tissue known as?

Answer 33

Waldeyer's ring

Question 34

Lymph from the palatine tonsil drains to one specific deep cervical lymph node. What is the name of this node?

Answer 34

The jugulo-digastric node.

Question 35

What happens to this node in response to infection? (eg. tonsilitis)

Answer 35

It enlarges.

Question 36

Where is the jugulo-digastric node located?

Answer 36

Located in posterior belly of digastric muscle.

Question 37

When looking at the lymphatic drainage of the tongue, where does the middle anterior section of the tongue drain to? Is this drainage bilateral or unilateral?

Answer 37

The middle anterior section of the tongue drains to the inferior deep cervical nodes. This drainage is bilateral.

Question 38

Where do the sides of the anterior section of the tongue drain to? Is this drainage bilateral or unilateral?

Answer 38

The sides drain UNI-laterally to submandibular nodes. Note: unilateral means the right side will only drain to right submandibular nodes and the left side would only drain to left submandibular nodes.

Question 39

Where does the tip of the anterior section of the tongue drain to? Is this drainage bilateral or unilateral?

Answer 39

The tip of the tongue drains BI-laterally to submental nodes.

Question 40

Where does the posterior 1/3rd of the tongue drain to? Is this drainage bilateral or unilateral?

Answer 40

The posterior 1/3rd of the tongue drains BI-laterally to superior deep cervical nodes.

Question 41

If a patient suffers from an infection (eg. dental abscess), what symptoms might they experience in their lymph nodes? What could be prescribed to treat the infection?

Answer 41

- swollen - painful - soft - smooth - not fixed (stuck to) adjacent structures Antibiotics can be prescribed as treatment.

Question 42

If a patient suffers from a cancer (eg. of tongue or gingivae), what symptoms might they experience in their lymph nodes?

Answer 42

- swollen - not painful - hard - irregular - fixed - do not improve

Question 43

What should the full examination of the dental patient include?

Answer 43

The full examination of the dental patient should include an assessment of the submental, submandibular and deep cervical lymph nodes.

Question 44

What groups of lymph nodes can be examined?

Answer 44

``` submental submandibular parotid mastoid occipital deep cervical (including jugulo-digastric) superficial cervical nodes ```