Lymphatic system Flashcards
Functions of lymphatic system (4)
Remove excess fluids from body tissues
Micro-organisms/ foreign materials
Products of fat digestion
Lymphocytes
5 structures of lymphatic system
Capillaries
Vessels
Ducts
Nodes
Tissues
Lymphatic capillaries (3)
= Smallest lymphatic vessels
Networks
Lacteals
How is lymph moved through lymphatic vessels
Passive movement of lymph through lymphatic vessels
Contraction of surrounding muscles
Backflow is prevented presence of valves
Function of afferent vessels?
Deliver lymph to lymph nodes
Function of efferent vessels?
Vessels which leave the lymph nodes
Function of lymph nodes?
Filter lymph that travels from tissues to ducts
Where are lymphocytes and phagocytic cells found?
Lymph nodes
What is removed through lymph nodes as lymph passes through them?
Invading micro-organisms
Dead cells
Debris
3 ducts?
Thoracic
Right lymphatic
Tracheal
Thoracic duct
Main lymphatic duct
Collects from almost all of the body
Drains into jugular vein or cranial vena cava
Right lymphatic duct
Drains from head, neck, thorax and right forelimb
Drains into right jugular or cranial vena cava
Tracheal ducts
Drains from head and neck
Drains into thoracic ducts or one of main vessels near heart
What does enlargement of individual lymph node suggests?
Infection and perhaps disease in process in that drainage area
Names of the 6 lymph nodes
Submandibular - below mandibles
Parotid - below ears
Prescapular - front of shoulders
Axillary - in axillae/ armpits
Popliteal - behind stifle joint
Superficial inguinal - in groin
Name the accessory lymphoid tissues (6)
Thymus
Spleen
Peyer’s patches
Tonsils (pharyngeal tonsils)
Vermiform appendix
Red bone marrow
What happens to micro-organisms when they invade the body?
Antigens are transported from tissue to the lymph
How is the lymph carried?
In lymph vessels to regional lymph nodes
Function/structure of tonsils
First line of defence against micro-organisms entering the mouth
Form a ring at junction of pharynx/ oral cavity
Which organs are part of the body first line of denfence? 3
Tonsils
Appendix
Peyer’s patches in intestine
Function/ structure of thymus
Lymphoid organ located in thoracic cavity in mediastinal space
Produces T lymphocytes and helps other lymphoid tissue to mature
Young animal: thymus in thoracic inlet
Adult: thymus may eventually disappear
Structure/ function of spleen
Attached to greater curvature of stomach and lies within omentum
Functions:
1. reservoir for RBC + platelets
2. Removes old RBC & recovers their iron
3. Filters out foreign particles/ bacteria from circulation
4. Produces lymphocytes
Function of lymph nodes
Remove particles
Produce lymphocytes
