Lymphatic System Flashcards
What are the main functions of lymph vessels? (2)
- Collection of tissue fluid and its return to the systemic circulation.
- Transport of lymphocytes and other cells.
What is tissue fluid comprised of? (3)
- Water
- Proteins
- Lipids
Where do the lipids extruded from blood capillaries go?
Into connective tissue matrix.
Approximately what percentage of tissue fluid is returned to the main systemic circulation via lymph vessels? What percentage is removed via blood capillaries and perspiration?
20%
80%
Under what conditions does lymphoedema result?
When fluid/protein return is compromised.
What is lymphoedema associated with? (2)
- Long-term inflammation
2. Connective tissue and immune changes
What is believed to be the primary cause of lymphoedema?
Protein retention in connective tissue, especially high molecular weight proteins, which are not readily absorbed by blood capillaries.
What part of the body is lymphoedema usually associated with?
Limbs, but can occur in any part of the body including head and neck if the lymph drainage is interrupted.
What are the most common causes of lymph drainage interruption?
Surgical interventions to remove lymph node metastases, blockage or interruption of vessels by tumour, injury or parasites.
Where is the majority of lymph returned to? (2)
Venous system in two places:
At junction of SUBCLAVIAN and INTERNAL JUGULAR VEINS.
Where are there additional connections into the venous system?
- IVC
- Renal
- Suprarenal
- Azygous
- Iliac veins
What type of tubes are lymph capillaries? Where are they located?
Blindly ending tubes
In connective tissue
Where do lymph capillaries start as and what do they come to form?
Initially a plexus then anastomose to form larger vessels.
Blood capillaries are more permeable than lymph capillaries. True or False.
False.
Lymph vessels can be very large. True or False.
False.
What is the largest lymph vessel?
Thoracic duct. Diameter: 2-5mm
All lymph vessels are very thin walled. True or False.
True
Lymph vessels do NOT form many anastomoses. True or False.
False.
How is lymph fluid transported?
Similar to veins:
- Gravity
- Muscle in walls (only in larger lymph vessels)
- External pressure
a) movement of adjacent viscera and muscles
b) suction - Numerous valves - pockets of vessel lining - usually in pairs
What do lymph vessels usually follow? What characteristic?
Larger blood vessels as a plexus.
Lymph vessels are always associated with lymph nodes. True or False.
False.
Where are lymph vessels not found? (3)
- CNS
- Bone marrow
- Avascular tissue (e.g. cornea, epidermis, cartilage)f
What are the functions of lymph nodes? (2)
- Immunoserveillance of lymph
2. Production of lymphocytes and other immune cells
How big are lymph organs?
1 - 25 mm long. Many are tiny.
What is a lymph node enlargement called? What is it a result of?
Lymphadenopathy
The result of infection or a tumour.
Lymph nodes are always associated with lymph vessels. True or False.
True.
Most lymph vessels pass through at least one node on its way back to the circulation. True or False.
True.
How many lymph nodes do we have?
Approximately 300-400.
Where are most of the lymph nodes located?
- Neck
- Thorax
- Abdomen
- Pelvis
- Groin
There are relatively few lymph nodes in limbs and none on the thoracic duct. True or False.
True.
What are some lymph organs?
- Spleen
- Thymus
- Tonsils
What is the thoracic duct formed by on the left side and lower body? Where?
The confluence of 5 major tributaries in the posterior abdomen:
- 2 lumbar lymph trunks
- 1 gastrointestinal lymph trunk
- 2 descending intercostal (thoracic) lymph trunks
What do the lumbar lymph trunks drain?
- Lower abdominal and pelvic walls
- Lower limbs
- Pelvic viscera
- Parts of the large intestine, kidneys and suprarenals.
What does the gastrointestinal lymph trunk drain?
- Liver
- Spleen
- Pancrease
- Stomach
- Small intesting and much more of large intestine
What does the descending intercostal lymph trunk drain?
Lower thoracic regions on both sides
Where does the descending thoracic lymph trunk pass?
Through the diaphragm to the start of the thoracic duct.
Where does the thoracic duct receive lymph from?
A large range of lymph vessels in the thorax.
What are the main tributaries for the thoracic duct? (3)
- Left subclavian lymph trunk
- Left jugular lymph trunk
- Left bronchomediastinal lympg trunk
Where does the left subclavian lymph trunk come from?
L upper limb
Where does the left jugular lymph trunk come from?
L head and neck
Where does the left bronchomediastinal lympg trunk come from?
Upper left throax
Where is the termination of the left subclavian, jugular and bronchomediastinal trunks?
Left jugulosubclavian junction
What is the thoracic duct formed by on the right side of the body? Where do each of these come from?
- R jugular (R head and neck)
- R subclavian (R arm)
- R bronchomediastinal (upper R thorax)
What do 20% of individuals have?
Right lymphatic duct formed by the right jugular, subclavian and bronchomediastinal trunks.
Where does the right lymphatic duct drain?
Into the right jugulosubclavian junction
What type of valves exist in lympg vessels?
Bicuspid valve
Where do we find the lymph valves?
At the junction of the venous system
What is the purpose of these valves?
Prevent or reduce regurgitation of blood in life
When are the valves non-functional? Where does it occur?
After death.
Terminal portion of the thoracic duct
The subclavian and bronchomediastinal trunks have valves at their termination, whereas, the jugular trunks do not. True or False.
True.
In the head and neck where does lymph from superficial tissues drain into? What is an alternative? Provide an example.
Superficial groups of nodes and then into deep nodes.
Alternatively, some drainage may be into deep nodes directly. (e.g. some of the drainage of the tongue)
Where do the deep chain of vessels and nodes eventually drain into?
Jugular lymph trunk
What are the superficial nodes of the head? (4)
- Occipital
- Retroauricular
- Parotid
- Buccal
What are the skin and superficial tissues drained by roughly? Provide an example.
Vertically disposed vessels to the nodes inferior to the tissues in questions. e.g. temporal region and lateral forehead drain into parotid nodes.
How many deep nodes are there in the head?
Relatively few
What do the deep nodes in the head include?
- Lingual nodes
2. Retropharyngeal nodes
What are the lingual nodes associated with?
Root of the tongue
Where is the retropharyngeal node?
Between upper pharynx and longus capitus (a prevertebral muscle)
Where do the deep nodes of the head ultimately drain into?
Deep cervical nodes
What are the superficial nodes of the neck?
- Superficial cervical (Over lateral surface of SCM)
- Submandibular (Between mandible and submandibular salivary gland)
- Submental (Overlie mylohyoid muscle)
- Anterior cervical (Over thyroid, larynx, trachea)
What may the deep nodes of the neck overlie?
- Carotid sheath
2. Internal jugular
How can the deep nodes be divided?
Superior and Inferior by a line marked by omohyoid muscles
What doe the superior/upper deep cervical nodes included? Where are they located?
- Jugulodigastric
- Retropharyngeal
Posterior to the pharynx.
What does the inferior/lower deep cervical nodes include?
Jugulo-omohyoid
Where is the jugulodigastric node located? (2)
- In the triangular region bounded by the posterior belly of digastric, facial vein and internal jugular.
- 1 - 2 cm below the angle of the mandible and are easily palpable especially when inflammed
What does the jugulodigastric node comprise of?
One large and several small nodes.
What does the jugulo-omohyoid node overlie?
Intermediate tendon of omohyoid
What are both the jugulodigastric and jugulo-omo hyoid concerned with?
Lymph drainage of the tongue and tonsils (possibly from both ipsilateral and contralateral)
There is an absence of deep lympg nodes between the pharynx and vertebral column and around tracher and larynx.
False.
Where do all lymph from head and neck eventually drain into?
Jugular Lymphatic trunks
In the oral cavity, where does much of the lymph from the floor of mouth and mandibular teeth and gingiva drain into? (2)
Submandibular and submental nodes and then into the deep cervical nodes.
Where does the hard and soft palate and maxillary teeth and gingiva drain? (2)
- Retropharyngeal nodes
2. There is also some direct deep drainage.
What does the tongue contain and where does it drain?
- Contains a plexus of lymph vessels
- with a wide distribution of drainage to submental, submandibular or to both upper and lower deep nodes via a variety of routes.
What is Virchow’s node? Where is it located?
Supraclavicular/anterior scalene nodes.
It is the lowest of the deep cervical group of nodes, located in the supraclavicular fossa just lateral to clavicular head of SCM.
What does the Virchow’s node consist of?
Consist of the group of nodes closest to the jugular trunk.
Which node is particularly prone to metastasis from malignancies in many other parts of the body?
The left supraclavicular/anterior scalene nodes
Where does the jugular trunk drain into?
The thoracic duct that in turn receives lymph from most of the body.
What is retrograde backflow at the venous termination of the thoracic duct prevent by?
A valve
Where do the subclavian and bronchomediastinal trunk also have valves at?
Junction with the thoracic duct
What appears to lack valves?
Jugular trunk
Where are possible sites of metastases in these nodes?
- Lungs
- Bronchi
- Breast
- Upper limb
- Stomach
- Intestines
- Prostate
- Testis
What are the tonsils? (3)
- 1 pharyngeal
- 1 lingual
- 2 palatine
Where is the pharyngeal tonsils located?
Beneath nasopharangeal mucosa in posterior of nasopharynx.
In children it is prominent around the opening of the auditory tube.
What are the enlarged pharyngeal tonsils called?
adenoids - mouth breathing
What are the lingual nodes?
A collection of lymph nodule in posterior or pharangeal
Where are the palatine tonsils?
- On lateral side of the oropharynx just behind the oral cavity
- Located in the tonsilar fossae between the palatoglossal and palatopharangeal folds.
What are the tonsils? (3)
- 1 pharyngeal
- 1 lingual
- 2 palatine
Where is the pharyngeal tonsils located?
Beneath nasopharangeal mucosa in posterior of nasopharynx.
In children it is prominent around the opening of the auditory tube.
What are the enlarged pharyngeal tonsils called?
adenoids - mouth breathing
What are the lingual nodes?
A collection of lymph nodule in posterior or pharangeal
Where are the palatine tonsils?
- On lateral side of the oropharynx just behind the oral cavity
- Located in the tonsilar fossae between the palatoglossal and palatopharangeal folds.