M26: Lymphatic System Flashcards
4 main components of lymphatic system
- lymphatic tissue
- red bone marrow
- lymph
- lymphatic vessels
what is the main purpose of the lymphatic system?
the body system that carries out immune responses
lymphatic tissue
- reticular CT with lymphocytes: B cells and T cells
- found in many structures and organs
primary vs secondary lymphatic organs/tissues
PRIMARY:
where stem cells divide to create the immuno-response cells
- RED BONE MARROW
- THYMUS
SECONDARY
where immune responses happen
- SPLEEN
- LYMPH NODES
- TONSILS
difference between tonsils and lymph nodes
- tonsils don’t have a capsule surrounding them
- not a lymphatic organ, just a mass of lymphatic cells
when lymphatic cells aren’t surrounded by a capsule it’s not considered an organ but…
lymphatic tissue
what makes lymphatic vessels different from small veins?
they’re very similar other than
thinner walls
more valves
what structures do lymphatic vessels follow in the body?
- superficial vessels tend to follow superficial veins
- deep vessels tend to follow arteries
cisterna chyli
- dilation in lymphatic vessels
- caused by merge in lumbar and intestinal trunks
- start of the thoracic duct
where does the thoracic duct attach to the vascular system
left subclavian vein
where is lymph drained from R side of body?
right lymphatic duct
right subclavian vein
functions of lymphatic system
- drains excess interstitial fluid
- transports dietary fats and lipid-soluble vitamins (A, D, E, K)
- carry out immune responses (targets microbes and abnormal cells)
lymphatic capillaries
- located between cells of many tissues
- larger and more permeable than blood capillaries
- endothelial cells organized for one-way flow of lymph
- merge to form lymphatic vessels
anchoring filaments
extensions of lymphatic capillary endothelial cells that attach it to neighbouring cells
special features of endothelial cells in lymphatic capillary to prevent backflow
overlapping endothelial cells
- when lymphatic capillary gets to full, openings will close off
name the 2 primary lymphatic organs
- thymus
- red bone marrow
difference between lymphatic capillary and blood capillary
lymphatic are larger in diameter and more permeable
flow of lymph
interstitial fluid
lymphatic capillaries
lymphatic vessels
lymph nodes
lymph trunks
lymph ducts (thoracic duct OR “right lymphatic duct”)
most people have drainage on R side of body go straight to R subclavian vein
subclavian veins
5 principle lymph trunks
main lymphatic trunks
LUMBAR: drains lower limbs, kidneys, adrenals, portions of pelvic and abdominal walls
INTESTINAL: drains stomach, intestine, pancreas, spleen, part of liver
BRONCHOMEDIASTINAL: drains thoracic walls, lungs, heart
SUBCLAVIAN: drains upper limbs
JUGULAR: drains head and neck
routes of lymph drainage
MOST OF BODY
- R and L lumbar merge with intestinal trunk at the cisterna chyli to form the thoracic duct
- merges with L jugular trunk and L subclavian trunk
- attaches to L subclavian vein (right at its junction with the L internal jugular vein)
- L bronchiomediastinal trunk attaches independently to L subclavian vein
UPPER RIGHT BODY
- R jugular, R subclavian and R brochiomediastinal trunk join independantly to R subclavian vein
small # of people will have these merge, called the right lymphatic duct
what lymphatic vessel does not join thoracic trunk and attaches to L subclavian vein independanty?
L bronchiomediostinal trunk
lymph nodes
filters for lymph
- remove foreign substances through filtering, phagocytosis and immune reactions
immunocompetent
cells that are able to create an immune response
where is thymus located
mediastinum
left side of body
