Lymph Flashcards
What are the 3 functions of lymph vessels?
1) Collection of tissue fluid and its return to the systemic circulation.
2) Transport of lymphocytes and other cells
3) Uptake and transport of long chain fatty acids absorbed in the intestine.
What is tissue fluid comprised of?
Plasma (water, proteins. lipids extruded from blood capillaries into connective tissue matrix)
How much of lymph fluid is returned to systemic circulation? How?
20%, via lymph vessels
What happens to the lymph fluid that is not returned to systemic circulation?
It is removed from blood capillaries and pespiration
What is the consequence if fluid/protein return is compromised?
Lymphoedema
Where are lymphocytes produced?
Lymph nodes
Where are lymph nodes located?
Along the course of larger lymph vessels and by other lymphatic organs and tissues.
What are some examples of lymphatic organs and tissues?
Spleen and gut associated lympatic tissue (GALT)
What does it mean to be a long chain fatty acid?
More than 12 carbons.
What is the fate of long chain fatty acids?
1) Absorbed by the intestinal epithelial cells
2) Transported across into extracellular space and into lymph vessels (lacteals) of the intestinal villi.
What happens to lymph in the lacteals?
Transported to thoracic duct and ultimately into bloodstream.
What is the fate of smaller fatty acids?
Taken up into bloodstream and then into the portal vein and the liver.
What are lymph capillaries? What are they initially? What do they become?
1) Blindly ending (arising) tubes in connective tissue
2) Plexus
3) Anastomose to form larger vessels.
Lymph vessels are large. T or F? What is the largest lymph vessel?
False.
Thoracic duct, 2-5 mm diameter.
The walls of lymph vessels are thick. T or F?
False. They are all very thin walled.
How does lymph fluid return?
Similar to veins. Gravity, pressure from adjacent organs, viscera etc. They also have lots of valves.
Even the small lymph vessels have their own vaso vasorum. T or F?
False. Only the larger lymph vessels have their own blood supply of small veseels forming a plexus in the wall.
Lymph vessels undergo fast repair. T or F?
True.
Lymph vessels undergo anastomoses only between vessels of similar sizes. T or F.
False. Lymph vessels anastomose between vessels of all sizes.
Lymph vessels often follow larger blood vessels on the internal surface.
False. Lymph vessels often follow larger blood vessels as a plexus on thier adventitia.
Lymph vessels are NOT found in the CNS, bone marrow and avascular tissue. T or F?
True. They are not found in cornea, epidermis and cartilage.
Lymph vessels are independent to lymph nodes. T or F?
False. They are associated.
Lymphatic organs can range from 25-50mm long. T or F?
False. 1-25mm.
What are the proliferative structures of the lymph system called?
Lymph nodules
What role does the lymph nodule have?
- Produce lymphocytes and other cells of the immune system which are involved in immunosurveillence of lymph
- Add lymphocytes to lymph
Lymph vessels can only pass through one node on it way back to the circulation. T or F?
False. They pass through at least one node.
How many lymph nodes are there in the neck, thorax, abdomen, pelvis and groin region?
300-400.
How many lymph nodes in the limbs?
Relatively few.
How are lymph nodes named?
According to whether they are superficial or deep and on the basis of associated structures.
Lymph nodes are ALWAYS situated along most lymph vessels. T or F?
True
Where do the afferent branches of the lymph vessels go?
They penetrate the capsule of the node.
What does lymph do through the sinuses in the node?
Percolates and collects lymphocytes produced in the node.
How does lymph leave the nodes?
Via one or several efferent vessels.
What do lymph nodes additionally produce?
Macrophages and plasma cells which are invovled in immunosurveillence of lymph.
What is the name given to the first node or group of nodes into which lymph from a particular organ drains?
Sentinal lymph node or nodes.
Where can the thoracic duct be located?
Between the azygos vein and aorta.
What is the thoracic duct a confluence of?
1) 2 lumbar trunks
2) 1 gastrointestinal trunk
3) 2 descending intercostal (throacic) trunks
What is the origin of the thoracic duct?
L2. Marked by the cisterna chyli.
Trough what does the throacic duct pass when it passes through the aortic hiatus?
Abdomen to thorax.
In the thorax, what does the thoracic duct pass through?
1) Posterior mediastinum (passes from right to left)
2) Passes posterior to the left IVC, brachiocephalic vein and internal jugular to enter the left jugulosubclavian junction.
Where does the thoracic duct in the thorax receive lymph from?
1) Mediastinal trunks from upper liver, diaphragm, heart, oesophagus
2) 5-6 upper intercostal trunks on either side
What are the tributaries of the thoracic trunk in the neck?
1) Left subclavian trunk (from left upper limb)
2) Left jugular (from left head and neck)
3) Left bronchomediastinal (upper left throax and heart)
What do the RIGHT subclavian, jugular and mediastinal trunks drain? What can potentially happen?
Similar territories to the left.
They converge to form a right lymphatic duct - which drains into the right jugulosubclavian junction.
What happens when the right lymphatic duct is not present?
The trunks enter the adjacent great veins separately. (Possible sites: subclaivan, internal jugular and/or IVC)
They are a multitude of lymph nodes along the thoracic duct or right lymphatic duct. T or F?
False. There are none.
How does lymph drain the skin and cutaneous structures?
Lymph drains into 3 sets of nodes on either side from distinct regions of the body defined by imaginary lines through clavicle and umbilicus and vertically through the midline.
What is the structure of the resting breast?
1) Mainly fibrous and adipose tissue
2) Some ducts but few alveoli (secretory part)
What is the structure of the breast during pregnancy and lactation?
1) Ducts and alveloi proliferate considerably and secrete during pregnancy and lactation.
2) Fibrous and fatty tisseus decreases.
What is the structure of the breast post-lactation?
Glandular tissue involutes and is replaced with fibrous tissue and fat.
What happens to lymph drainage during malignancies?
Lymph drainage is implicated.
What is the function of the auxiallary group of nodes?
- About 75% of lymph from breast drain into the auxillary group of nodes.
- Also receives almost all the lymph from the upper limb.
Where does the remaining lymph from the breasts go?
1) Drains to the infraclavicular and parasternal.
2) Some go to intercostal nodes
3) Abdominal nodes and cross midline.
What happens if normal lymph channels are blocked?
The lymph may go to inferior deep cervical nodes and or contralateral
Are the superficial and deep plexuses interconnected?
Yes.
What are the inguinal nodes?
2 interconnected groups
What categories are there for superficial nodes?
1) Proximal group
2) Distal Group
Where are the superficial proximal nodes found?
Along the inguinal ligament.
What do the superficial proximal nodes receive?
1) Vessels from external genitalia, anal regions and skin below level of umbilicus.
2) Some of the vessels from the uterus also drains to the proximall group (lymph vessels travel with the round ligament)
Where can we find the superficial distal nodes?
Along termination of great saphenous vein.
What do the superifical distal nodes receive?
Receive superficial vessels from lower limb.
Where can we locate deep nodes?
1-3 deep nodes deep and medial to femoral vein.
Where do efferent vessels from superficial and deep inguinal nodes drain to?
External and common iliac nodes and aortic nodes.
What do the efferents from aortic nodes form?
Lumbar trunks.
Where do we find lymph nodes in the lower limbs?
Sparse, but can be found in populiteal fossa (behind knee)
What do the intestinal lymph trunk drain?
Most of the abdominal organs, especially alimentary system.
What do the intestinal lymph trunk vessels follow?
Major anterior branches of the abdominal aorta. (coeliac, superior and inferior mesenteric arteries)
What is the node through which the lymph vessels of the intestinal trunk collectively called?
preaortic nodes
How are lumbar lymph trunks formed?
From lymph vessels that follow iliac vessels and sides of the aorta.
What do lumbar lymph trunks drain?
Urogential organs, posterior body wall and lower limbs.
What are assoicated nodes of the lumbar lymph trunk called?
Lateral aortic or lumbar nodes.
Not many anastomoses exist between the tributaries of the various lymph trunks. True or Flase?
False. Numerous anastomoses exist between the tributaries of the various lymph trunks.
Where do lower thoracic vessels drain?
Into descending thoracic lymph trunks that contribute to the formation of the cisterna chyli/origin of thoracic duct.
Where do upper thorax vessels drain?
Into bronchomediastinal lymph trunks and from there into the jugulosubvlacian junctions.
Others drain into the thoracic duct in the thorax.
Where are lymph vessels likely to be found in the lungs?
At the hilus of the lung (where vessels enter and leave) or along bronchi especially at the branching.
Where do superficial and deep pleural vessels ultimately drain?
Bronchomediastinal lymph trunks.
What is the highest point reached by the thoracic duct?
C7 as it arches up behind internal jugular before entering jugulo-subclavian junction - posterior to clavicle.
