click
on this image for an audio messageUse these web resources to supplement your studies of lecture notes and objectives.
Textbook (sample quizzes, labeling)-select a chapter number in pull down menu.
More online tutorials
I Main functions:
1) Collect fluids/lymph and return it to the venous blood, maintaining
blood volume.
2) Immunosurveillance
3) absorption of dietary fats in intestine
II. Lymphatic flow:
The following vessels are involved in lymph production, flow and return to
the veins.
A. Lymph Capillaries:
- endothelium/simple squamous epithelium
- They are found throughout most tissues and among
blood capillaries.
B. Lymphatic Vessels:
- They receive lymph from the capillaries.Lymph produced by capillaries eventually
carried to and through
lymph nodes by these vessels.
- Have the same three tunics as veins, but have thinner walls.
- Have more valves.
C. Lymphatic Ducts:
- They are larger than the collecting vessels.
- The vessels drain into the trunks.
- They form as the largest vessels meet.
- They drain large regions of the body.
They drain/return lymph into the venous supply where the subclavians
and internal jugulars meet.
1) Right Lymphatic Duct:
Drains lymph only from the right arm, right side of head,
and right thorax which drains into the right subclavian Vein.
2) Thoracic Duct/Left Duct:
Drains the upper left side and entire lower part of body which drains into the left subclavian Vein.
click
on this image for an audio message
II. Primary Lymphoid Organs:
All produce lymphocytes and also contain macrophages (aggressive monocytes). These cells provide the functions of these organs.
A. Diffuse lymphatic tissues (nodules without connective tissue capsule)
Examples include:Tonsils and adenoids of oral cavity; and, Peyer's Patches in
intestine
B Lymph Nodes:
Surrounded by capsule, Nodules in cortex, lymph vessels in medulla. Located along lymph vessels.
They contain many B cells and some T cells (lymphocytes, remember).
B (plasma cells) produce antibodies which neutralize, immobolize or agglutinate
microbes.
T cells attack microbes and lyse their membranes (cytolysis)
C.. Spleen: largest lymphoid organ.
Anatomically like a large lymph node but resist disease (see above functions of cells in these organs) from pathogens from blood, not lymph.
On the left side of the abdominal cavity.
Functions: 1) Site of lymphocyte proliferation.
2) Immunosurveillance (lymphocytes monitoring for microbes)
3) Removes old erythrocytes, platelets, debris,
pathogens, toxins from blood.
4) Stores iron.
5) Stores platelets.
6) Is the site of rbc production in the fetus.
D. Red bone marrow
Production of all blood cells, including lymphocytes
click
on this image for an audio message
III Secondary lymphatic organs
A. Thymus:
This is the only lymphoid organ that does not directly resist disease or pathogens.
- Anterior and superior to the heart.
- Produces thymosin which makes T cells immunocompetent.(mature and active)
Helpful
web link
A
web activity
--------------------------------------------------------------------------------
Professor Thomas M. Lancraft
Human Anatomy Courses
at St. Petersburg College
St. Petersburg/Gibbs Campus
11/2009