Overview of the Lymphatic System Flashcards
What are the functions of lymphatics and immune systems?
Draining excess interstitial fluid to bloodstream
Transport dietary lipids
Immune responses
What would happen in the absence of a lymphatic capillary?
with time, fluid would build up in the tissue which would leave rise to oedema
Where does interstitial fluid re-enter circulation?
Capillaries at venous ends
Lymphatic capillaries
What is tissue fluid called when it enters lymphatics?
Lymph
What feature is highly present in lymph vessels?
Valves
What percentage of tissue fluid is returned into circulation?
10-20%
Are lymph capillaries permeable?
Highly so allowing entry of tissue fluid, bacteria, viruses and cancer cells
What is the role of lymphatics?
Collect lymph from lymph capillaries
Where are lymphatics found?
They accompany blood vessels
How do lymph vessels differ from blood vessels?
Contains more valves than veins
More frequent interconnections
Arranged in networks
What happens in lymph nodes?
Screening of lymph
Where are lymph capillaries absent in the body?
CNS
Bone marrow
Avascular tissue
Name examples of avascular tissues
Articular and other cartilages
Nails
Epidermis
Cornea
Hair
What name is given to specialised lymphatic capillaries?
Lacteals
Where are lacteals located?
Villi of small intestine
What is the role of lacteals?
Receive digested fats
What name is given to the fatty lymph?
Chyle
Where does lymph from the limbs drain to?
Where limbs are attached to the trunk
What is found on the external surface of a lymph node?
Fibrous capsule
What name is given to lymph vessels that enter the lymph node?
Afferent
What name is given to lymph vessels that leave the lymph node?
Efferent
What is the function of lymph nodes?
Lymph percolates through and antigens are destroyed and activate B & T lymphocytes
Where does lymph NOT pass through series of nodes?
Paired viscera on posterior abdominal wall e.g. kidney, ovary, testis
Thyroid gland
Where do paired viscera on the posterior abdominal wall drain to?
Para-aortic nodes without being filtered in any outlying nodes
Where does the thyroid gland drain to?
Directly into neck veins without any nodes
What are the 7 major lymph trunks?
Right & left jugular trunks
Right and left subclavian trunks
Right and left bronchomediastinal trunks
Thoracic duct (biggest)
Where do the jugular trunks drain from?
Head and neck
Where do the subclavian trunks drain from?
The upper limbs
Where do the bronchomediastinal trunks drain from?
Much of the thoracic cavity
Where does the thoracic duct drain from?
Drains most of lymph below diaphragm and some posterior structures
Where does all lymph eventually drain into?
Right lymphatic duct and thoracic duct
What does the right lymphatic duct drain?
Right side of head
Right upper limb
Right side of thorax
What is unusual about the right lymphatic duct?
Only present in 15-20% of the population
What is the course of the thoracic duct?
Begins as cisterna chyli
Ascends along vertebral bodies
Empties into venous circulation (junction of left IJV and left subclavian veins)
Where does the right lymphatic duct empty?
Right IJV and subclavian veins
What factors propel lymph towards venous system?
Contraction of skeletal muscle
Pulses in arteries
What cells are found in the lymphatic system?
Lymphocytes
What are the encapsulated lymphatic organs?
Lymph nodes, spleen, thymus
Where is the thymus located?
anterior mediastinum
What is the role of the thymus?
Lymphocyte maturation
When does the thymus have the fastest rate of growth?
First year of life
When does the thymus decrease in size?
60 years
What are the simplest lymphoid organs?
Tonsils
What are the names of the groups of tonsils?
Palatine tonsil
Pharyngeal tonsils
Lingual tonsils
Where are the palatine tonsils found?
Side of mouth
Where are the pharyngeal tonsils found?
Above the palette
Where are lingual tonsils found?
Back of tongue
What is the role of the tonsils?
Forms a ring around border between oral cavity and pharynx
Gather and remove pathogens
Where is the spleen located?
Left side in abdomen
When are spleens often damaged?
Road traffic accident due to fractured rib
What is the function of the spleen?
Detects and responds to foreign substances
Destroys defective RBCs
Limited reservoir for blood
Where are Peyer’s patches found?
Located in distal part of small intestine
What does MALT stand for?
Mucosa associated lymphoid tissue
What is the role of Peyer’s patches and the appendix?
Fight invading bacteria
Where is the appendix located?
Tubular offshoot of caecum
What is chylothorax?
Leakage of fatty lymph into thorax
What is mononucleosis?
Viral disease caused by Epstein-Barr virus
Attacks B lymphocytes
What is another name for mononucleosis?
Glandular fever
What is lymphangitis?
Inflammation of lymph vessel
What does an acute bacterial infection cause in the Lymphatic system?
Draining lymph nodes are enlarged, tender and painful
Lymphatics have lymphangitis - tender reddened streaks
What is Hodgkin’s disease?
Malignancy of lymph nodes
What is non-Hodgkin’s Lymphoma?
Uncontrolled multiplication and metastasis of undifferentiated lymphocytes
Where does tumour of epithelia drain to?
Lymph nodes
Where would you examine to confirm a tumour in the breast of your patient?
Axillary lymph nodes
What is a metastases?
Secondary deposit of cancer cells in lymph node
In malignant cells, how do lymph nodes present?
Enlarged but not tender
