Lymphatic Structures And Lymph Flow Flashcards
Describe the anatomical features of lymph nodes
Connective tissue capsule Supporting strands of CT inside Marginal sinus Clusters of lymphocytes ( below marginal sinus) Medullary zone Trabecula ( collagen,elastin fibres) Afferent vessels ( enter the LN) Efferent vessels (leave the LN) Artery, vein and nerve
List 4 important functions of lymph nodes
To prevent noxious material entering the bloodstream.( ie.cells:bacteria viruses, organic chemicals, dust, dyes.)
Housing and storing them
Reproduce lymphocytes
Regulate the concentration of the lymph ( protein content) filtering
Describe the structure and their orientation in the superficial fascia of lymph collector vessels
Lymph collector vessels are transport vessels
and maintain lymph flow, they drain lymph from striplike skin zones.( several skin zones form a territory)
They are bigger than a pre collector
The vessel walls have 3 layers intima, media and adventitia.
The intima consists of endothelial cells with flaps( valves)
(Between two valves are segments called lymphangions)
The valves control the direction of flow
Pre collectors
Precollector is both a transport and collecting vessel
It can absorb LOL in sm amounts and transport lymph from initial LV to to collectors
They are interconnected with skin zones.
They are smaller than collectors and bigger than ILV
Initial lymph vessels
Initial lymph vessels are the smallest vessels and form the beginning of the lymphatic vascular system.
Found in the entire dermis and drain LOL from the connective tissue.
They have a blind origin in the tissue like fingers in a glove.
They cosist of a single layer of endothelial cells that overlap on the edges so they open like shutter valves.
The ILV transports the LOL to the precollectors.
What is a lymphangion?
Any portion of the lymph vessel thats between two valves is a lymphangion.
Name 3 mechanisms which control smooth muscle in collector vessels
Stretch receptor reflex
Automyogenic activity
Sympathetic system
What mechanisms allow uptake of fluids by the ILV
Muscle and joint pump Arterial pulsation Respiration and peristalsis Negative pressure in the thorax- when pressure is low valves close, when pressure is up it pulls on the anchoring filaments attached to endothelial cells that open the valves External pressure ( MLD and bandaging)
List at least six functions of the LVS
To circulate lymphocytes- immune system Removal of fluid leaked out by capillaries in CT spaces Removal of lge proteins and lipids Removal or organic and inorganic waste maintain blood volume
What are the intrinsic mechanisms which control lymph flow?
Walking... changing pressure between thorax and abdomen Negative pressure in the thorax Muscle and joint pump Arterial pulsation Respiration and peristalsis
What are the extrinsic mechanisms which control lymph flow?
External pressure
MLD and Bandaging
What increases lymph flow?
Walking Negative pressure in the thorax Exercise (muscle and joint pump) walking- SRR MLD Respiration and peristalsis External pressure
What decreases lymph flow?
Inactivity , lack of movement
What are 3 ways protein get taken out of a cell?
Might get used by a body cell
Might get deleted ( macrophage may eat them)
Majority are taken up by the Lymph system
What is a low protein oedema?
Dynamic oedema
What cells are carried by LOL?
B and T lymphocytes- (mostly T some B- body does reassortment- best chance of having right cell at right time- because circulation is one way B cell has to go thru whole system subclavian etc.B stay mostly in lymphoid tissue)
Macrophages-( when in blood called monocytes)
Dendritic cells( veiled cells)
Other WBC’s
Dead and dying cells
Mutated fragments
Cell fragments
What is a dendritic cell?
Type of macrophage- lives just under the skin dormant until theres a problem
Then jumps in a LV to a node to a lymphocyte and becomes an antigen producing cell- non specific defenses
What cells would you find in a wound?
Lots of macrophages
They always leave tissue thru L/ system- full of bad stuff so dont want to bring it back into the blood
What are the components of lymph?
Water
Proteins
Long chain fatty acids
( milky if lipids are present- if proximal to cysterna chyli or thoracic duct)
What are the components of Lymph obligatory load?
Major and minor.
Major =
Proteins, lipids/ fats, cells, water
Minor=
Dust, dyes, pathogens, antigens, cellular debris
How much fluid can the LVS filter per day?
2 1/2 liters per day
How do long chain fatty acids enter the blood circulation?
Through diffusion and osmosis? ( vitamins A K E)
Enter around the small intestines to cysterna chyli
What is filtration?
Liquid pressed out through a membrane
Higher pressure- more water
Hydrostatic pressure- is less than the cells- anything that fits is forced through under high pressure
What is Osmosis?
Liquids with varying particle concentration
separated by a semi permeable membrane
Force is applied by protein molecules
What is the Transit stretch?
Transit stretch pushes cells away from their nutrients- oedemas
Define Lymphoedema
Chronic
High protein Oedema
Define Primary lymphoedema
Genetic - born with it
Impaired Lymph system
Damage to structure
Define Organic lymphoedema
Damage or absence of vessels or nodes
Define secondary lymphoedema
Organic lymphoedema
Damage ot Lvessel or nodes due to surgery, mastectomy, trauma
Define functional lymphoedema
Intact L vessels and nodes
Problem with LV function- post polio
Stroke
List 4 Absolute contraindications to MLD
Congestive heart failure
Acute infection
Untreated tumour
Acute thrombosis- people in planes, joint replacements are highest risk
Acute phlebitis
List 10 relative contraindications and explain how treatment can be modified
Edit
Describe 3 ways MLD can have an analgesic effect
Edit
What effects does MLD have on smooth muscle in the blood vessels
Refer to notes
What effects does MLD have on smooth muscle in the lymph vessels?
Increases the transport capacity
Empties proximal vessels- movt of the skin SRR
How many times per minute does the stretch receptor reflex fire?
27-30 x p/ min
What does the skeletal m pump do?
Stretches skin
Explain the thoraco abdominal pump
Allows lymph to flow more
Explain the pulsation of arteries
Edit
What is the role of MLD in connective tissue?
Maintain gel balance
