Lymphatic system Flashcards
(50 cards)
what does the lymphatic system do
returns fluids that have leaked from the vascular system back to the blood.
what are the 3 parts of the lymphatic system
lymphatic vessels, lymph, and lymph nodes
what is lymph
the fluid contained in those lymphatic vessels
what are Lymph nodes
nodes that cleanse the lymph as it passes through
them
The lymphoid organs and tissues provide the structural
basis of the
immune system
the lymphoid organ and tissues play a huge role in what
in the body’s defense mechanisms and its resistance to disease
name some structures of the lymphatic system
spleen, thymus, tonsils, and other lymphatic tissue scattered throughout the body
the ______ and ___________ operating at capillary beds force fluid out of the blood at the _____ ends of the beds (“____”) and cause
most of it to be reabsorbed at the ______ ends (“_____”). The fluid that remains behind in the tissue spaces, as much as 3 L daily, becomes part of the ________
hydrostatic colloid osmotic pressure arterial upstream venous downstream interstitial fluid
__________
elaborate networks of ______ vessels that collect the excess _____________and return it to the bloodstream.
lymphatic vessels/lymphatics
drainage
protein-containing interstitial fluid
Once interstitial fluid
enters the lymphatic vessels, it is called
lymph
The lymphatic vessels form a ______ system in which lymph flows only _____ the heart.
one way
towards
The transport of lymph begins in microscopic blind-ended
lymphatic capillaries
lymphatic capillaries
weave between the __________ and __________- in the _______ of the body.
tissue cells
blood capillaries
loose connective tissues
Lymphatic capillaries are widespread,
but they are absent from
bones (including bone marrow) and teeth
Lymphatic capillaries were long thought to be absent
from the central nervous system, but recent evidence shows that they are present but restricted to limited locations in the
meninges
the lymphatic capillaries in the brain meninges help do what
drain the extracellular fluids in the brain
interstitial and cerebrospinal fluids
what are the two unique structural modifications that allow lymphatic capillaries to be permeable
1) The endothelial cells forming the walls of lymphatic capillaries are not tightly joined. 2)Collagen filaments anchor the endothelial cells to surrounding structures
The endothelial cells forming the
walls of lymphatic capillaries are
not tightly joined. Instead what is going on
the edges of adjacent cells overlap each other loosely, forming easily opened, flaplike ,minivalves
(shown at right).
why do Collagen filaments anchor the
endothelial cells to surrounding structures
so that any increase in interstitial fluid volume opens the minivalves, rather than causing the lymphatic capillaries to collapse.
When fluid pressure in the interstitial space is greater than the pressure in the lymphatic capillary, the minivalve flaps gape
open, allowing fluid to enter the lymphatic capillary.
when the pressure is greater inside the lymphatic capillary, it forces the endothelial minivalve flaps
shut, preventing lymph from leaking back out
as the pressure moves it along the vessel
Proteins in the interstitial space are unable to enter _____, but they enter _______ easily.
blood capillaries
lymphatic capillaries
when tissues become inflamed, lymphatic capillaries
develop ____________ such as cell debris, pathogens (disease-causing microorganisms such as bacteria and viruses), and cancer cells.
openings that permit the uptake of even larger particles
the particles that lymphatic capillaries pick up where do they go
These particles travel with the lymph to the lymph nodes, where they are removed by cells of the irnmune system
