Flashcards in Chapter 7.2 The Lymphatic System Deck (14):
what is the critical test of the T lymphocytes?
If any show the ability to react with the individual's cells, they will die in the thymus.
Why is the thymus important to immunity?
Because without mature properly functioning T cells, the body's response to specific pathogens is poor or absent.
What are the secondary lymphatic organs?
Spleen, lymph nodes, and other organs containing lymphoid tissue. These include the tonsils, Peyer's patches, and the appendix.
Describe the spleen
Filters blood. It is the largest lymphatic organ and is located in the upper left region of the abdominal cavity posterior to the stomach.
What does the connectives tissues role play in the spleen?
Divides the spleen into regions known as white pulp and red pulp
Describe red pulp in the spleen
It surrounds venous sinuses (cavities), and is involved in filtering the blood.Blood entering the spleen muss pass through the sinuses before exiting. Here, macrophages that are like powerful vacuum cleaners engulf pathogens and debris, such as worn out blood cells.
What can cause a spleen to burst?
The spleen's outer capsule is relatively thin, and an infection or a blow can cause the spleen to burst.
What happens to a person without a spleen?
Although the spleen's functions are replaced by other organs, a person without a spleen is often slightly more susceptible to infections and may have to receive antibiotic therapy indefinitely.
Describe Lymph nodes
They occur along lymphatic vessels, filter lymph.
What is connectives tissues role in lymph nodes?
It forms a capsule and also divides a lymph node into compartments. Each compartment contains a sinus that increases in size toward the center of the node. As lymph courses through the sinuses, it is exposed to macrophages, which engulf pathogens and debris. Lymphocytes, also present in sinuses, fight infections and attack cancer cells.
What are lymph nodes named for?
Define lymphatic nodules
They are concentrations of lymphatic tissue not surrounded by a capsule. The tonsils are patches of lymphatic tissue located in a ring about the pharynx.
What is the function of tonsils?
They perform the same functions as lymph nodes; but because of their location, they are the first to encounter pathogens and antigens that enter the body by way of the nose and mouth.