Vasculature - Lymphatics

Question 1

What are the functions of the lymphatics?

Answer 1

1) Drain tissue fluid, plasma proteins and other cellular debris back into the blood stream.
2) Immune defence

The fluid running in this system is called lymph.

Question 2

There are two major groups of lymphatic vessels in the head. These are the…

Answer 2

1) Superficial vessels - drains lymph from the scalp, face, and neck into the superficial ring of lymph nodes at the junction of the neck and head.

2) Deep vessels - these arise from the deep cervical lymph nodes. They converge to form the right and left jugular lymphatic trunks:
i) Left jugular lymphatic trunk - combines with the thoracic duct at the root of the neck. It empties into the venous system via the left subclavian vein.

ii) Right jugular lymphatic trunk - forms at the root of the neck. Empties into the venous system via the right subclavian vein.

Question 3

Superficial lymph nodes

Answer 3

1) Occipital - occipital area of the scalp
2) Mastoid - posterior neck, upper ear, external auditory meatus
3) Pre-auricular - superficial areas of the face and temporal region
4) Parotid -
i) Superficial - nose, nasal cavity, external auditory meatus, tympanic cavity, lateral orbit.
ii) Deep - nasal cavity, nasopharynx
5) Sub-mental - central lower lip, apex of tongue, floor of the mouth
6) Sub-mandibular - cheeks, lateral nose, upper lip, part of the lower lip, gums, anterior tongue
7) Facial - nose, cheeks, eyelids, conjunctive
i) Infraorbital
ii) Maxillary
iii) Sub-mandibular
8) Superficial cervical - superficial neck

These all drain into the deep lymph nodes.

Question 4

Deep lymph nodes

Answer 4

Receives lymph from superficial lymph nodes.

Organised in a vertical chain adjacent to the internal jugual vein, within the carotid sheath.

The efferent vessels of the deep cervical nodes converge together to form the jugular lymphatic vessels.

These are the pre-laryngeal, pretracheal, paratracheal, retropharyngeal, infrahyoid, jugulodigastric (tonsillar), jugular-omohyoid, and supraclavicular nodes.

Question 5

Clinical relevance - Virchow’s node

Answer 5

This is a supraclavicular node located in the left supraclavicular fossa (located immediately above the clavicle). It receives lymph drainage from the abdominal cavity.

An enlarged Virchow’s node indicates the Troisier’s sign - and indicates the presence of a cancer in the abdomen, specifically gastric cancer, that has spread throughout the lymph vessels.

Question 6

Waldeyer’s ring

Answer 6

The tonsils of Waldeyer’s ring line the tissue around the superior pharynx. The following tonsils are:

1) Lingual - posterior base of tongue (antero-inferior part of ring).
2) Palatine (x2) - either side of palatoglossal and palatopharyngeal arches. these are tonsils that can be seen within the oral cavity (lateral part of the ring).
3) Tubal (x2) - located where the Eustachian tube opens into the nasopharynx (lateral part of the ring).
4) Pharyngeal (adenoid) - roof of the nasopharynx, behind the uvula (postero-superior part of the ring)

Question 7

Clinical relevance - inflamed paltine tonsils (tonsilitis)

Answer 7

These can be inflamed due to a viral or bacterial infection.

They can then appear red, enlarged, and are accompanied with large jugulo-digastric nodes.

Chronic tonsilitis can be treated with tonsillectomy. While performing this procedure, there may be bleeding from the external palatine vein, and secondarily from the tonsillar branch of the facial artery.

Complication - in infection spreads to the peri-tonsillar tissue it can lead to formation of an abscess. This leads to deviation of the uvula - this is known as a quinsy. This is a medical emergency. It can cause obstruction of the pharynx. Treated by draining the abscess and antibiotics.

Question 8

Lymphatics of the brain?

Answer 8

Yet to be determined by scientists.