LQB185 Chapter Notes - Chapter 22: Lymphatic Vessel, Lymph Node, Reticular Connective Tissue
25 May 2018
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Chapter 22- Lymphatic and Immunity System
22.1 Lymphatic System Structure and Function
➢ Lymphatic system consists of:
- a fluid called Lymph
- vessels called Lymphatic vessels that transport the lymph
- several structures and organs containing lymphatic tissue,
- red bone marrow
➢ works to circulating body fluids and helps defend the body against
disease-causing agents.
➢ Difference between lymph and interstitial fluid is location.
- Interstitial fluid is found between cells
- Lymph is found within lymphatic vessels and lymphatic tissue
➢ Lymphatic Tissue
- Specialised form of reticular connective tissue
- Contains large amounts of lymphocytes
- Lymphocytes are agranular white blood cells, 2 types of lymphocytes
(B cells and T cells)
➢ Function of Lymphatic System
- drain excess interstitial fluid
- Transport dietary lipids
- Carries out immune Reponses
➢ Lymphatic vessels and lymph circulation
- Lymphatic vessels being as Lymphatic capillaries.
- When Lymphatic capillaries converge back together that create larger
Lymphatic vessels. Have thinner walls and more valves that veins
- Throughout the body these vessels flow into Lymph nodes bean-
shaped organs consisting of masses of B cell and T cells
➢ Lymphatic Capillaries
- Greater permeability than blood capillaries thus absorb more
molecules
- Only one-way structure that permit interstitial fluid to flow into them
but NOT OUT.
- Attached to Lymphatic capillaries are anchoring filaments which
contain elastic fibres.
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- The small intestines have specialised Lymphatic capillaries called
lacteals that carry dietary lipids into Lymphatic vessels -> into blood
➢ Lymph Trunks and Ducts
- Once Lymphatic vessels pass through the lymph nodes they unite to
form lymph trunks.
- Principle Trunks
1. Lumbar Trunks- drains lymph from lower limbs, wall and viscera
of pelvis, kidneys, adrenal glands and abdominal wall
2. Intestinal Trunks- drains lymph from stomach, intestines,
pancreas, spleen and part of liver
3. Broncho mediastinal Trunks- drain lymph from thoracic wall, lung,
and heart
4. Subclavian Trunks- drain upper limbs
5. Jugular Trunks- drain head and neck
- From the trunks, lymph passes into two main channels
1. Thoracic (Left Lymphatic) Duct
2. Right Lymphatic Duct
➢ Formation and Flow of Lymph
- Excess filtered fluid from the blood capillaries is drained into the
lymphatic vessels and become lymph
- Because plasma protein is too large to leave blood vessels, interstitial
fluid contains a small amount of that protein, because lymphatic
vessels are permeable they play an important role in returning the
lost plasma proteins and plasma to the blood stream
- Blood capillaries (blood) -> interstitial space (interstitial fluid) ->
lymphatic capillaries (lymph) -> lymphatic vessels (lymph) ->
lymphatic ducts (lymph) -> junction of the internal jugular and
subclavian veins (blood)
- Pumps that aid return of venous blood to heart maintain flow of
lymph
1. Skeletal muscle pump
2. Respiratory pump
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Vessels called lymphatic vessels that transport the lymph. Several structures and organs containing lymphatic tissue, Works to circulating body fluids and helps defend the body against disease-causing agents. Difference between lymph and interstitial fluid is location. Lymph is found within lymphatic vessels and lymphatic tissue. Lymphocytes are agranular white blood cells, 2 types of lymphocytes (b cells and t cells) When lymphatic capillaries converge back together that create larger. Have thinner walls and more valves that veins. Throughout the body these vessels flow into lymph nodes bean- shaped organs consisting of masses of b cell and t cells. Greater permeability than blood capillaries thus absorb more molecules. Only one-way structure that permit interstitial fluid to flow into them but not out. Attached to lymphatic capillaries are anchoring filaments which contain elastic fibres. The small intestines have specialised lymphatic capillaries called lacteals that carry dietary lipids into lymphatic vessels -> into blood.
