A: Lymphatic system Flashcards
Lymphatic capillaries function
Take in fluid that leaves capillaries and doesn’t re-enter capillaries, so that fluid doesn’t build up In tissues and cause oedema.
Lymph node function
Lymph is screened for pathogens as it goes through the lymph node. Lymph goes through, antigens are destroyed as B + T lymphocytes are activated.
Lymph capillaries
- Smallest lymph vessels
- High permeability allows entry of tissue fluid but also bacteria, viruses + cancer cells.
Lymphatics
- Collect lymph from lymph capillaries
- Accompany blood vessels
- Walls similar to blood vessels
- Contain more valves than veins
- Interconnects more frequently
- Many arranged as networks
Lymph capillaries are present in all tissues of body except:
- Central nervous system
- Bone marrow
Lymph capillaries are not present in avascular tissues such as:
- Articular + cartilages
- Nails
- Epidermis
- Cornea
- hair
Lacteals
- Specialized lymphatic capillaries
- Located in villi of small intestine
- Receive digested fats
- Fatty lymph has white consistency and is called chyle.
Lymphatics of skin
run independently of other vessels, drain in to nodes where limbs are attached to trunk.
Difference between afferent and efferent lymph vessels
Afferent lymph vessels: enter lymph node
Efferent lymph vessels: leave lymph node.
Major lymph vessels
- Right & left jugular trunks: drain head & neck
- Right & left subclavian trunks: drain upper limb
- Right & left bronchomediastinal trunks: drain a lot of thoracic cavity
- Thoracic duct: drains most of lymph below diaphragm + some posterior thoracic structures.
2 main lymphatic ducts
- Right lymphatic duct: right head, right upper limb, right thorax
- Thoracic duct: remainder of body.
Thoracic duct
Begins as cisterna chyli
Ascends along vertebral bodies
Empties into junction of left IJV & left subclavian vein
Right lymphatic duct empties into…?
Empties into right IJV + subclavian veins.
Thymus
- Located in superior mediastinum
- Contains immature lymphocytes which develop into T lymphocytes
- Function = lymphocyte maturation –> primary lymphoid organ
Tonsils
- Palatine tonsils
- Pharyngeal tonsils
- Lingual tonsils
