and return it to the bloodstream
The lymphatic system is closely connected with what other body system? - ANSWER Car-
diovascular system
What are three functions of the lymphatic system? - ANSWER (1) The lymphatic vessels
take up excess tissue fluid and return it to the bloodstream. (2) Lymphatic capillaries absorb
fats and transport them to the bloodstream. (3) The lymphatic system helps with immunity
to defend the body against disease.
What is lymph? - ANSWER Excess tissue fluid entering the lymphatic capillaries from the
interstitial fluid not returned by the cardiovascular system.
Describe the flow of lymph. - ANSWER The lymph flows one way, from the lymphatic ca-
pillary system to the subclavian veins, where it joins the venous circulation to return to the
heart.
True or false: Lymph vessels are only found in the lower extremities. - ANSWER False
Describe the structure of lymph vessels. - ANSWER Lymph vessels have one-way flow
valves similar in structure to the large veins of the cardiovascular system. The valves prevent
the backward flow of lymph. The return of the lymph fluid into circulation is solely depend-
ent on the squeezing action of skeletal muscles, squeezing the fluid one way through the
lymphatic vessels.
The right lymphatic duct drains into the ________. - ANSWER Right subclavian vein
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, True or false: The thoracic duct drains fluid from the right arm. - ANSWER False-the left
arm
Describe the structure of a lymph node. - ANSWER A lymph node is encapsulated in a fi-
brous connective tissue with many incoming and fewer outgoing lymphatic vessels. Incoming
vessels (afferent vessels) flow through a network of sinuses that contain cells. The lymph
then flows out of the lymph node through the efferent vessel. The interior of the lymph
node is divided into open spaces called nodules, containing lymphocytes and macrophages.
What is the axilla region? - ANSWER Armpit
The spleen is in what region of the body? - ANSWER The spleen is in the upper left abdo-
men.
What is the function of the spleen? - ANSWER The spleen functions to extract old or de-
fective blood cells and platelets. The spleen also removes debris, foreign matter, bacteria,
viruses and toxins from the blood that flows through it.
After blood exits the spleen via the splenic vein, where does it travel? - ANSWER Blood
leaves the spleen via the splenic vein which flows to the hepatic portal vein (also called the
hepatic portal system). The hepatic portal system carries blood drained from the veins of the
spleen, intestines, stomach and pancreas to the liver. The hepatic portal vein transports
blood into the liver where it is detoxified before returning to general circulation.
Locate the thymus and describe its function. - ANSWER The thymus gland is located on
anterior surface of the heart. The thymus secretes thymosin and thymopoietin hormones
which enable T lymphocytes (T cells) to mature and function as part of the immunity system.
Mature T cells attack body cells which are cancerous or infected with pathogens.
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