Lymphatic System (Questions - EXAM #2) Flashcards
What does the lymphatic system consist of?
The lymphatic system consists of lymphatic vessels, lymph nodes, and lymphoid cells, tissues, and organs.
What is the primary function of the lymphatic system?
It collects and returns approximately 10% of extracellular fluid (lymph) from tissues to the venous blood, helping to cleanse it and support immune function.
What do lymph nodes do in the lymphatic system?
Lymph nodes filter lymph as it passes through, removing bacteria, viruses, and cancer cells.
What is the difference between intracellular and extracellular fluid?
Intracellular fluid is found within cells (~40% of body weight), while extracellular fluid is outside cells and includes blood plasma (~5% body weight), interstitial fluid (ISF, ~15%), and lymph (~1%).
What is interstitial fluid (ISF)?
ISF is the fluid between cells, and some of it moves into lymphatic capillaries to become lymph.
What is lymph?
Lymph is the fluid inside lymphatic vessels, derived from ISF, and is eventually returned to the blood plasma.
How does lymph move through the lymphatic system?
Lymph enters lymphatic capillaries, moves through larger collecting vessels, and is filtered by lymph nodes. It then drains into either the right lymphatic duct or the thoracic duct.
What is the function of one-way valves in the lymphatic vessels?
They ensure that lymph flows in one direction and prevents backflow.
What does the right lymphatic duct drain?
The right lymphatic duct drains lymph from the right side of the head, chest, and arm, and empties into the right subclavian vein.
What does the thoracic duct drain?
The thoracic duct drains lymph from the left side of the body and below the ribs, and empties into the left subclavian vein.
Where does the thoracic duct start?
The thoracic duct begins at the cisterna chyli, an enlarged portion of the vessel that collects lymph from below the ribs.
What is the role of lymphoid tissues and organs?
They contain lymphocytes and play a key role in the body’s immune response.
What are primary lymphoid organs?
Primary lymphoid organs are where lymphoid stem cells divide and mature. These include red bone marrow and the thymus gland.
Where do B lymphocytes proliferate and mature?
B lymphocytes proliferate and mature in the red bone marrow.
Where do T lymphocytes proliferate and mature?
T lymphocytes proliferate and mature in the thymus gland.
Where do mature lymphocytes migrate after maturation?
Mature lymphocytes move into the bloodstream and migrate to secondary lymphoid organs.
What is the function of secondary lymphoid organs?
Secondary lymphoid organs are where lymphocytes detect pathogens, activate immune responses, and proliferate further.
What is the function of lymph nodes?
Lymph nodes filter lymph, removing pathogens and foreign substances.
Where are lymph nodes commonly located?
Lymph nodes are concentrated in the cervical, axillary, inguinal, intestinal, and pelvic regions.
What does the spleen do?
The spleen filters blood by removing pathogens, old blood cells, and cellular debris.
Where is the spleen located?
The spleen is located on the left side of the abdominal cavity, just below the diaphragm, next to the stomach.
What is Mucosal Associated Lymphoid Tissue (MALT)?
MALT includes lymphoid tissues found at points of entry into the body, such as the tonsils, appendix, and Peyer’s patches in the small intestine.
What is the function of tonsils in MALT?
Tonsils trap and remove pathogens entering through the mouth or nose. They form a ring around the pharynx.
What are the types of tonsils?
There are three types: pharyngeal tonsil (adenoids when infected), palatine tonsils, and lingual tonsils.
What is the cisterna chyli?
The cisterna chyli is an enlarged portion of the thoracic duct that collects lymph from the lower body before it enters the thoracic duct.
What is the role of the lymphatic capillaries in the small intestine?
Lymphatic capillaries in the small intestine, called lacteals, play a key role in absorbing fats from digested food.
