What is the lymphatic system?
A network of drainage vessels
What does the lymphatic system consist of?
- Fluid - lymph
- Drainage vessels
- Lymphatic tissues
What are the lymphatic tissues?
Lymph nodes, a type of lymphoid organ
How many lymph nodes are there in the body?
How many lymph nodes are there in the neck?
Describe the structure of lymph nodes
Connective tissue structures, with a tough, fibrous outer capsule, and reticular connective tissue inside
What do lymph nodes contain?
Large collections of lymphocytes and macrophages
Where do lymph nodes play a key role?
In immune defence
What do all substances transported in lymph pass through?
1 or more lymph nodes
What immune defences do lymph nodes have?
- Physical filter
- Phagocytic filter
- Full of lymphocytes
What happens to the lymphocytes in lymph nodes?
They activate and proliferate in response to antigens
Where are the specific regions in the body where lymph nodes may be palpable?
- Neck (cervical)
- Armpit (axillary)
- Groin (femoral)
What may lymph draining into lymph nodes contain?
What are the lymphoid organs?
What happens to the lymph fluid?
It returns to the blood circulation
Where are lymph vessels found?
Throughout the body, with a few exceptions
What parts of the body do not have a lymphatic circulation?
- Inner ear
Why is there debate regarding the lymphatic circulation of the CNS?
Recent research has identified small lymphatic vessels lining the dura
How can lymph nodes be organised?
Into regional (or superficial) and terminal (or deep) groups
How are regional and terminal lymph nodes seperated?
By investing layer of deep cervical fascia in the neck
What are the regional groups of lymph nodes found in the area of the head and neck?
- Pre- and post- auricular
What do regional lymph nodes do?
Drain specific areas
Where do regional lymph nodes in the neck lie?
Superficially within superficial cervical fascia
What is the result of regional lymph nodes lying superficially within superficial cervical fascia?
They can be readily palpated, especially when enlarged
Where does lymph from superficial lymph nodes drain?
Into the deep lymph nodes
Where does the submandibular node drain?
- Upper lip and teeth
- Lateral lower part of lip
- Most of face
- Anterior nasal cavity
- Tongue (middle)
- Submandibular and sublingual glands
Where does the submental node drain?
- Lower lip/teeth (central)
- Anterior chin
- Tip of tongue
- Floor of mouth
Where does the pre-auricular node drain?
- Anterior part of ear (auricle)
- Parotid gland
- Some sources indicate conjunctiva and eyelids
Where does the post-auricular (mastoid) lymph node drain?
- Posterior part of ear (auricle)
- Ear canal
Where does the occipital lymph node drain?
Occipital area of scalp and neck
Where do the superficial cervical lymph nodes drain?
Skin of neck
What are the deep cervical lymph nodes of the head and neck?
- Jugulo-digastric (also called tonsillar node)
Which deep cervical lymph node is most frequently enlarged?
Where is the jugulo-digastric node located?
Just below and behind the angle of the mandible
What does the jugulo-digastric lymph node drain?
- Palatine tonsil
- Oral cavity
- Posterior 1/3 of tongue
What is the jugulo-omohyoid lymph node mainly associated with?
Lymph drainage of;
- Oral cavity
- Thyroid gland
Where are the supraclavicular lymph nodes found?
In root of neck on either side
Where do the supraclavicular lymph nodes recieve lymph from?
The abdomen and thorax
What happens to the lymph drained from the abdomen and thorax to the supraclavicular node?
It drains via the thoracic duct into venous circulation
What is the left supraclavicular node known as?
What does Virchow's node drain?
Abdomen and thorax
What does the right supraclavicular node drain?
- Mid section chest
Where do terminal lymph nodes lie within the neck?
Deep to the investing layer of cervical fascia
What do the terminal lymph nodes of the head and neck recieve?
All lymph of the head and neck, either directly or indirectly from regional groups
What are the terminal lymph nodes of the head and neck closely related to?
The carotid sheath, in particular the jugular vein
Describe the path of lymph in the head and neck
Head and neck superficial lymph nodes drain into deep cervica lymph nodes, which surround the IJV before draining via the thoracic duct into the subclavian vein
What is the most common cause of swelling in the neck?
Enlarged cervical lymph nodes
What may an enlarged lymph node signal?
Disease in the area it drains
What diseases can be indicated by an enlarged cervical lymph node?
- Infection (most common)
How do enlarged lymph nodes feel in infection?
How do enlarged lymph nodes feel in malignancy?
What should be done if a lymph node is found to be enlarged?
- Comprehensive history
- Examine area of tissue it drains
- If malignancy is supsected, examine other lymph nodes and body systems
What is lymphodema?
An abnormal collection of protein-rich fluid causing tissue swelling due to compromised lymphatic system
What can cause lymphodema?
- Removal or enlargement of lymph nodes
- Damage to lymphatic system
- Lack of limb movement
What kind of infections may cause lymphodema?
How may the lymphatic system be damaged?
Why can lack of limb movement cause lymphodema?
Muscle contraction assists movement of lymph fluid
Give an example of a congenital condition that can cause lymphoedema?
When is the jugulo-digastric node swollen and tender?
When may the jugulo-omohyoid node be enlarged?
In infection or disease of tongue, oral cavity, trachea, oesophagus, or thyroid gland
When may supraclavicular lymph nodes be enlarged?
In late stages of malignancies of abdomen and thorax
Is an enlarged left supraclavicular lymph node always pathological?
What is Trosier's sign?
An enlarged, hard, left supraclavicular lymph node
What is Trosier's sign considered a sign of?
A sign of metastatic abdominal malignancy