ANATOMY OF
LYMPHATIC SYSTEM
Mario Makarević
2nd year
2013/2014
Mentor: A. Žmegač Horvat
Lymph
• fluid similar to blood plasma
• no erythrocytes or platelets
• less proteins
• more leukocytes
• filters out of blood vessels
• lymph capillaries collect interstitial fluid
Composition
• lymphatic vessels
• lymphatic organs
• lymphatic tissue
Lymphatic vessels
• lymph capillary
•
•
•
•
single layer of overlapping endothelial cells
blind end
absent from brain, spinal cord, splenic pulp, bone marrow
located next to blood capillaries in tissue spaces
Lymphatic vessels
• lymph vessels
• afferent and efferent
• three-layered wall thinner than vein
• semilunar valves, contractile
lymphangion
Lymphatic vessels
• lymph trunks
• confluence of many efferent lymph vessels
•
•
•
•
•
jugular lymph trunks
subclavian lymph trunks
bronchomediastinal lymph trunks
lumbar lymph trunks
intestinal lymph trunk—unpaired
Lymphatic vessels
• lymph ducts
• right lymphatic duct and thoracic duct
• return fluid to blood
• right lymphatic duct
• about 1.5 cm in length
• right venous angle
• lymph from right half of head, neck,
thorax and right upper limb
• thoracic duct
• about 38-45 cm in length
• > front of L1 as cisterna chyli – emulsified
fats and free fatty acids absorbed by lacteals
• > aortic hiatus of the diaphragm
• > ascends along on the front of the vertebral
column, between thoracic aorta and azygos
vein
• > left venous angle
Lymph nodes
•
•
•
•
collections of stationary lymph tissue
from a few millimeters to about 1–2 cm long
fibrous capsule
afferent lymph vessels entering at the periphery, efferent
lymph vessels emerging at the hilum
• cortex and medulla
Cortex
• outer region directly beneath capsule
• densely packed lymphocytes (B-cells) arranged in follicles –
germinal center when challenged with an antigen
• deeper cortex – T-cells
• subcapsular sinus drains into trabecular
Medulla
• inner region
• strands called medullary cords – B-cells, macrophages and
plasma cells
• large blood vessels
• medullary sinuses
Major sites of lymph node
concentration
•
•
•
•
cervical – head and neck
axillary – hand, arm and breast
mediastinal – abdominal cavity
inguinal – lower extremities and external genital organs
Diffuse lymphatic tissue
•
•
•
•
not enclosed by a capsule
reticular connective tissue with lymphatic nodules
almost every organ, lamina propria of mucous membranes
tonsils, Peyer’s patches, appendix
Lymph circulation
• must be returned to blood stream to maintain blood volume
and pressure
• antibodies, lymphocytes, and monocytes
• obstruction leads to edema
Lymph circulation
• no central pump
• slow movement
• lymph is kept moving by:
• contraction of adjacent skeletal muscle and arterial pulsation
• contraction of smooth muscles – peristalsis
Metastasis
• bacteria or body cells spread from one body part to another
• breast cancer to axillary nodes
• chemotherapy
Sources
• http://www.innerbody.com/image/lympov.html
• http://en.wikipedia.org/wiki/Lymphatic_system
• https://www.boundless.com/physiology/the-lymphaticsystem/
• http://www.cea1.com/anatomy-sistems/lymph-capillaries/