lymphatic system Flashcards
lymphatic system contents
- lymph
- lymphatic vessels
- lymphoid organs
the lymph consists of…
- ISF
- lymphocytes
- macrophages
the lymph fluid drains 1/10th of the ISF from the body
primary lymphoid organs
- thymus
- bone marrow
thymus function
- site of maturation for T cells produced by lymphocytes
- produce thymulin and thyroxine
bone marrow function
- site of B cell and NK cell maturation
secondary lymphoid tissue
- tonsils
- nodes
- spleen
- mucosa-associated lymphoid tissue
notable nodes
- axillary
- cephalic
- inguinal
why is the spleen part of the lymphatic system?
the white pulp (lymphocytes) of the spleen takes care of worn out RBCs
mucosa associated lymphoid tissue
- GALT
- VALT
- NALT
GALT = gut associated lymphoid tissue
VALT = vulvo-vaginal associated lymphoid tissue
NALT = nasal associated lymphoid tissue
efferent and afferent lymphatic vessels
enter and exit the lymph nodes
they are one way vessels into the lymph nodes that do not permit backwards flow of lymph
similarities to circulatory vessels
- valves
- thin walls
the valves of the lymphatic system prevent backwards flow
lymphatic system functions
- produce, maintain, distribute lymphocytes
- maintain normal blood volume
- alternate transport for…
hormones
nutrients
waste
3 cell types of the lymphatic system
- T cells –> cell mediated immunity
- B cells –> antibody mediated immunity
- NK cells –> viral and cancer cell response
lymphatic system and blood volume maintenance
the lymphatic system is connected to the circulatory system
it can drain 1/10th of the ISF to maintain the blood volume
the other 9/10th of ISF is drained into the veinous system
small lymphatic vessels are AKA…
lymphatic capillaries
large diameter lymphatic vessels are AKA…
lymphatic ducts
lymphatic capillary characteristics vs vascular capillaries
- larger diameter
- thinner walls
- irregular outline
- anchoring filaments
- greater permeability
- tunics are difficult to identify
anchoring filaments prevent the lymph vessels from collapsing on themselves
superficial lymphatic location and supply
in the subcutaneous layer
supplies the mucous lining of the…
1. digestive
2. respiratory
3. urinary
4. reproductive tracts
supplies serous lining of the…
1. pericardium
2. peritoneum
3. pleura
deep lymphatic location and supply
collects lymph in the…
- skeletal muscle
- neck
- limbs
- trunk
- visceral organs
where are lymphatic capillaries not found in?
in areas that lack blood supply
- cartilage matrix
- cornea
major lymphatic trunks
the convergence of superficial and deep lymphatic vessels
- lumbar
- intestinal
- bronchomediastinal
- subclavian
- jugular
right trunks and their drainage
- right jugular
- right lymphatic
- right subclavian
- right bronchomediastinal
all right trunks empty into the right subclavian vein
left trunks and their drainage
- left jugular
- left subclavian
- left bronchomediastinal
- thoracic duct (left lymphatic)
all trunks drain into the left lymphatic (thoracic duct) which drains into the left subclavian and then the superior vena cava
body regions that drain into the thoracic duct
- left arm
- left torso
- left neck
- left head
- abdomen
- both legs (right and left lumbar)
75% drainage
body regions that drain into the right lymphatic duct
- right head
- right neck
- right arm
- right torso
25% drainage
cisterna chyli
saclike structure at the start of the thoracic duct
t cell types
- cytotoxic –> killer T
- helper –> helps B cells mature into plasma cells
- suppressor –> stops B cell maturing
- memory –> remember invading antigens
b cell types
- plasma cells –> antibody producing
- memory b cells –> remember an invading antigen
NK cells
- attack foreign cells
- attack normal infected cells
- attack cancer cells
“immunological surveillance cells”
lymphocyte immune response sequence
- macrophages eat foreign substances
- present foreign antigens to T cells
- T cell divides into cytotoxic, helper and memory T cells
helper T cells produce cytokines to help B cells grow and produce antibodies
macrophages use MHC to present antigens
antibody-antigen interaction on invading material
draws leukocytes to kill the bacteria
lymphocyte distributions
8 : 1 T cells and B cells in the blood
1 : 1 T cells and B cells in the spleen
1 : 3 T cells and B cells in the bone marrow
lymphocytes live 4-20 years
lymph nodule characteristics
- aggregation of lymphocytes in reticular tissue
- germinal center that contains lymphocytes
lymphoid tissue types
- MALT
- tonsils
- aggregated lymphoid nodules
5 tonsils
1x pharyngeal tonsil
2x palatine tonsils
2x lingual tonsils
lymph node characteristics
1-25 mm in diameter
high concentration of lymph nodes in…
1. cervical region
2. axillary region
3. abdominal region
4. inguinal region
5. breasts
lymph node structures
- afferent vessels
- capsule
- subscapular space
- outer cortex
- medulla
- medullary cords
- hilum
- efferent vessels
where are lymphoid tissue and nodules highly concentrated?
in areas of susceptible to high injury
cervical lymph node service
the head and neck
axillary lymph node service
filters lymph from trunk and arms
also from mammary glands in women
popliteal lymph node service
lymph from the legs
periauricular lymph nodes
in front of the ear
retroauricular lymph node
behind the ear
inguinal lymph node service
lymph of the lower limbs and trunk
thoracic lymph node service
lymph from the lungs, respiratory passages, mediastinal structures
abdominal lymph nodes service
lymph from urinary and reproductive systems
intestinal lymph node service
lymph from the digestive tract
mesenterial lymph node service
lymph from the digestive tract too
thymus characteristics
- larger in youth
- diminishes with age
- left and right thymic lobes
- medulla and cortex
- thymic corpuscles (hassal’s)
thymus cortex
- stem cells differentiate to form T cells
- mature T cells migrate to the medulla
thymus medulla
- matured T cells
- thymic corpuscles
hassal’s corpuscles
theorized to take care of corrupted thymocytes
spleen characteristics
- largest lymphoid organ
- attached to the stomach by the gastrosplenic ligament
- white pulp
- red pulp
- diaphragmatic surface
- visceral surface
- capsule
visceral surface of the spleen
organs that touch the spleen make impressions here
it also contains the hilum of the spleen
