Lymphatic System I Flashcards
The lymphatic system collects _____ and _____ from interstitial regions and returns them
to the blood.
fluid; proteins
Lymphatic capillaries are extremely _____ and they can therefore collect not only fluid but
also proteins and even cells.
porous
Specialized lymphatic capillaries participate in digestion by absorbing _____.
lipids and lipid-soluble
substances
. One of the major functions of the lymphatic system is to _____ the interstitial fluid.
purify
One of the lymphatic system’s tasks is to destroy cells which are not normally found in the
body, but sometimes it is unsuccessful in destroying _____; it is not uncommon for these
cells to invade lymphatic tissue and begin to grow.
cancer cells
The fluid in the lymphatic system is called _____.
lymph
About 3 liters per _____ travels through the lymphatic system, compared with 5 liters per
_____ through the circulatory system.
day; minute
Lymph can flow in only one direction because of _____ in the lymphatic vessels.
one-way valves
Lymph is primarily propelled toward the site where it is returned to the blood by _____,
although _____ in the vessel walls also participates.
the motions of the body;
smooth muscle
The smallest lymphatic vessels are called _____ and are essentially microscopic, dead-end tubes.
lymphatic capillaries
Endothelial cells that make up the lymph capillaries overlap loosely to form _____.
one-way valves
Increased fluid pressure in regions surrounding lymph capillaries causes the overlapping
regions of the cells of the capillaries to _____.
separate
High pressures in the lymph fluid within the lymphatic capillaries cause the overlapping
regions of the cells of which the capillaries are made to _____.
press together
Lymphatic capillaries are prevented from collapsing as tissue fluid increases by anchoring
_____ attached to the endothelial cells of the vessel.
collagen filaments
_____ are specialized lymph capillaries in the _____ of the small intestine.
Lacteals; villi
Most lymph in the body appears _____, but that in lacteals (called _____) is creamy white
due to the high concentration of lipids.
clear; chyle
When several lymph capillaries merge, they form a(n) _____.
lymphatic collecting vessel
The walls of lymphatic collecting vessels, like those of blood vessels, have _____ tunics.
three
When lymphatic collecting vessels merge, they form _____.
lymphatic trunks
There are nine major lymphatic trunks: two each of the _____, _____, _____ and _____
trunks, and one of the _____ trunk.
lumbar; jugular; subclavian;
bronchomediastinal; intestinal
When lymphatic trunks merge, they form the largest lymphatic vessels in the body, the
_____. (There are only _____ of these in the body; in some individuals, the
_____ one is absent and several trunks drain into the venous system directly.)
lymphatic ducts; two; right
Lymph from the legs, several abdominal organs and the lower torso enters the left
lymphatic (a.k.a. thoracic) duct via a dilated sac called the _____.
cisterna chyli
The left and right lymphatic ducts drain into the left and right _____ veins, at their
intersection with the _____.
subclavian; jugular veins
Blood is prevented from entering the lymphatic ducts by the presence of _____.
one-way valves
The _____ collects lymph from the bulk of the body, including one entire side of the body
and regions on the opposite side below the thorax.
left thoracic lymphatic duct
The _____ collects lymph only from a small portion of one side of the body.
right lymphatic duct
One major class of white blood cells, the \_\_\_\_\_, take their name from their presence in the lymphatic system.
lymphocytes
One major class of lymphocytes, the \_\_\_\_\_, are formed in the bone marrow, but mature in the thymus gland.
T-cells or T lymphocytes
_____ attack cells in the body that are not recognized as normal members of the body’s
cellular community.
T-cells or T lymphocytes
_____ are a type of blood cell that develops and matures in the bone marrow before
moving to the lymphatic system.
B-cells or B lymphocytes
A(n) _____ is any large molecule with a unique shape which can be recognized by the
immune system.
antigen
. When _____ encounter an antigen, they divide to form plasma cells and memory cells.
B-cells or B lymphocytes
_____ release antibodies which bind to antigens.
Plasma cells
_____ circulate in the lymph and blood for many years, and respond rapidly if an antigen
encountered in the past is again encountered.
Memory cells
Many _____, cells that are descended from monocytes and which engulf microbes and
debris, are found in the lymph fluid.
macrophages
The lymphatic system’s supporting structure is provided largely by _____ cells and the
fibers they produce.
reticular
Lymphatic tissues are classified depending on the _____ and whether or not it is
surrounded by a(n) _____.
distribution of the cells; capsule
Lymphatic tissues in the _____ (a vascular layer of connective tissue under the basement
membrane of epithelium, particularly mucosal epithelium), in general, are referred to as
_____.
lamina propria; mucosa-associated lymphoid tissue (MALT)
When MALT is found in the gastrointestinal tract, it is referred to as _____.
gut associated lymphoid tissue
GALT
_____ is lymphatic tissue in which lymphocytes and macrophages are only loosely
associated with the reticular fiber network, and which is not clearly separated from
surrounding tissues.
Diffuse lymphatic tissue
