S3) Lymphatic Drainage of the Head and Neck Flashcards
What does the lymphatic system consist of?
- Lymph nodes
- Lymphatics
- Lymph fluid
What is the purpose of the lympathic system?
Continuous removal of residual tissue fluid from the extracellular space (via a series of lymph nodes) to be returned back to blood circulation
Lymph is just tissue fluid which has entered the lymphatic capillary.
Identify some of the contents of lymph
- Lipids (chylomicrons from gut lymphatics)
- Small proteins
- Damaged cells
- Tissue fluid
- Bacteria
How much lymph does the body produce a day?
3 ‐ 4 L of lymphatic fluid produced per day
What danger is associated with the lymphatic vessels?
A route for the spread of infection and malignant disease
Illustrate how uni-directional flow occurs in the lymphatic system
Tissue fluid → lympathic capillary → lymphatic vessels → lymphatic nodes → lymphatic vessels → lymphatic trunks → lymphatic ducts → venous system
The lymphatic system is a low pressure system with no central pump.
How does the lymph flow?
- Valves: passive and intrinsic constriction
- Pulsation of an artery (close association)
- Muscle contraction
Where in the venous circulation does the lymph drain?
Lymphatic system ends in two main lymphatic ducts which drain into subclavian veins
What is lymphoedema?
Lymphoedema is the abnormal collection of protein‐rich fluid causing tissue swelling due to compromised lymphatic system
Lymphoedema is a chronic condition.
Identify 5 of its causes
- Removal / enlargement of lymph nodes
- Infections e.g. certain parasites
- Damage to lymphatic system e.g. cancer treatments
- Lack of limb movement
- Congenital
Provide 3 examples of lymphoid organs in the body
- Spleen
- Tonsils (Waldeyer’s ring)
- Thymus
Describe the structure of lymph nodes
Connective tissue structures:
- Tough fibrous outer capsule
- Reticular connective tissue inside
Describe, briefly, how lymph nodes provide defence against infection
- Physical filter
- Phagocytic filter
- Lymphocytes: activate and proliferate in response to antigens
Enlarged lymph nodes is a very common patient presentation.
Which two underlying conditions cause this?
Lymphadenopathy:
- Infection – most common, tender, mobile
- Cancer – hard, matted, non-tender
What should one do when a patient presents with enlarged lymph nodes?
- Comprehensive history
- Examine the area of tissue it drains
- Examine other lymph nodes and body systems (if malignancy is suspected)
Lymph nodes in the head and neck can be classified into two groups.
Identify them and describe their function
- Regional: receive drainage from scalp, face and neck (ring)
- Terminal: receive drainage from regional nodes (vertical)
Describe the relative depth of terminal and regional lymph nodes
- Regional = superficial
- Terminal = deep
Identify the 5 regions in body where collections of lymph nodes may be palpable
How many lymph nodes are in the body?
Of those, how many can be found in the neck?
- 800 lymph nodes in the body
- 300 lymph nodes in the neck
Where are regional lymph nodes located?
Superficial to the investing layer of deep cervical fascia
Where are the terminal lymph nodes located?
- Deep to the investing layer of deep cervical fascia
- Most are associated with IJV (in carotid sheath)
Identify the following superficial lymph nodes 1-5:
1) Submental
2) Submandibular
3) Pre-auricular
4) Post-auricular
5) Occipital
Identify the following cervical lymph nodes 6-8:
6) Superficial: EJV
7) Posterior: EJV
8) Anterior: AJV
Identify the following deep lymph nodes 9-11:
9) Jugulo‐digastric (tonsillar node)
10) Jugulo‐omohyoid
11) Supraclavicular lymph nodes
