OUTLINE:
I. LYMPHATIC SYSTEM
i. Origins Of The Lymphatic System:
Capillary Beds
ii. Lymphatic Structure
a. Lymph
b. Lymphatic Vessels
c. Lymphoid Organs
iii. What Does Lymphatic System Do?
II. IMMUNE SYSTEM
i. Innate Defense System
a. External Barricade
b. Internal Innate Defenses
c. Inflammatory Response
ii. Adaptive Defense System
a. Humoral Immunity
b. Cell-Mediated Immunity
LYMPHATIC SYSTEM
- A security line; checkpoints – has the ability to take
care of small infections on the spot
- It takes up some extra fluid, and runs a background
check
- Quietly plays a vital supporting role to both
cardiovascular and immune systems
It maintains homeostasis by eventually returning most
of the fluid that has been diverted back into the blood
ORIGINS OF THE LYMPHATIC SYSTEM: CAPILLARY BEDS
- Capillary beds – where the capillaries carry blood
from arterioles and feed blood into venules
oWhere transfer of nutrients and waste takes
place
- As blood plasma force plasma out of the arteriole
end of the capillaries and into the interstitial fluid
between the cells. And most fluid gets drawn right
back into the capillaries on the venous end through
OSMOTIC PRESSURE
THE LYMPHATIC SYSTEM STRUCTURE
- Consists of 3 main parts:
oLymph
oLymphatic vessels
oLymphoid organs
LYMPH
- A watery fluid that flows through your lymphatic
system.
- This solution does nor contain RBC, which remain in
the closed circulatory loop because they are too
large to pass through capillary membranes.
- Starts out as blood plasma, that’s forced out of the
capillaries, way down in the capillary beds, where
there is leakage
LYMPHATIC VESSELS
LYMPHATIC VESSELS
- A network of lymphatic vessels that help reabsorbs
the fluid that are left behind
- 17 out of 20 liters is taken back up by the venous
end
- Other 3 liters becomes the lymph
- Lymphatic capillary
oAll over the body, but notably absent from
bones, bone marrow, teeth, and the CNS
oLoosely overlapping, endothelial cells,
forming flaplike mini valves that only open
in one direction
Lymph flows through larger lymphatic vessels
(LYMPH NODES) to collecting vessels
then to large trunks (LYMPH TRUNK)
and, into one of two big ducts ( LYMPH DUCT) that
feed back into the lowest pressure area of the
circulatory system
RIGHT LYMPAPHATIC DUCT – drains all the lymph
collected from the upper right area of the torso, arm,
head and thorax, and feeds them all into the internal
jugular vein
LARGER THORACIC DUCT – takes lymph from the rest of
the body and dumps it into the subclavian vein
- lymphatic vessels operate under very low pressure,
have a series of valves that prevent backflow, and
are helped along a bit by smooth muscle in the
vessel walls that keep the fluid moving
LYMPHATIC NODES
-LYMPH NODES – Checkpoints that monitor and
cleanse the lymph nodes, as it filters through
- Main lymphoid organs
- Regular inspection by lymphocytes
- Depending on what microorganism they find in the
fluid, lymphocytes can trigger the release of
macrophages or activate the general immune
system
