Flashcards in Chapter 22 Lymphatic System Deck (99)
What tissue contains stem cells that develop into lymphocytes?
Red bone marrow contains stem cells that develop into lymphocytes.
Is lymph more similar to blood plasma or interstitial fluid? Why?
Lymph is more similar to interstitial fluid than to blood plasma because the protein content of lymph is low.
Which lymphatic vessels empty into the cisterna chyli, and which duct receives lymph from the cisterna chyli?
The left and right lumbar trunks and the intestinal trunk empty into the cisterna chyli, which then drains into the thoracic duct.
Does inhalation promote or hinder the flow of lymph?
Inhalation promotes the movement of lymph from abdominal lymphatic vessels toward the thoracic region because the pressure in the vessels of the thoracic region is lower than the pressure in the abdominal region when a person inhales.
Which type of lymphocytes mature in the thymus?
T cells mature in the thymus.
What happens to foreign substances in lymph that enter a lymph node?
Foreign substances in lymph that enter a lymph node may be phagocytized by macrophages or attacked by lymphocytes that mount immune responses.
After birth, what are the main functions of the spleen?
White pulp of the spleen functions in immunity; red pulp of the speen performs functions related to blood cells.
When do lymphatic tissues begin to develop?
Lymphatic tissues begin to develop by the end of the fifth week of gestation.
What chemicals are responsible for killing ingested microbes?
Lysozyme, digestive enzymes, and oxidants can kill microbes ingested during phagocytosis.
What causes redness during inflammation?
Redness results from increased blood flow due to vasodilation.
What causes pain during inflammation?
Pain results from injury of nerve fibers, irritation by microbial toxins, kinins, and prostaglandins, and pressure due to edema.
What causes heat during inflammation?
Heat results from increased blood flow and heat released by locally increased metabolic reactions.
What causes swelling during inflammation?
Swelling results from leakage of fluid from capillaries due to increased permeability.
Which type of T cell participates in both cell-mediated and antibody mediated immune responses?
Helper T cells participate in both cell-mediated and antibody-mediated immune responses.
What is the difference between an epitope and a hapten?
Epitopes are small immunogenic parts of a larger antigen; haptens are small molecules that become immunogenic only when they attach to a body protein.
What types of cells are APCs, and where in the body are they found?
APCs include macrophages in tissues throughout the body, B cells in blood and lymphatic tissue, and dendritic cells in mucous membranes and the skin.
What are some examples of endogenous antigens?
Endogenous antigens include viral proteins, toxins from intracellular bacteria, and abnormal proteins synthesized by a cancerous cell.
What are the first and second signals in activation of a T cell?
The first signal in T cell activation is antigen binding to a TCR; the second signal is a costimulator, such as a cytokine or another pair of plasma membrane molecules.
What is the function of the CD8 protein of a cytotoxic T cell?
The CD8 protein of a cytotoxic T cell binds to the MHC-I-molecule of an infected body cell to help anchor the T cell receptor (TCR)-antigen interaction so that antigen recognition can occur.
In addition to cells infected by microbes, what other types of target cells are attacked by cytotoxic T cells?
Cytotoxic T cells attack some tumor cells and transplanted tissue cells, as well as cells infected by microbes.
How many different kinds of antibodies will be secreted by the plasma cells in one clone?
Since all of the plasma cells are part of the same clone, they secrete just one kind of antibody.
What is the function of the variable regions in an antibody molecule?
The variable regions recognize and bind to a specific antigen.
Which pathway for activation of complement involves antibodies? Explain why.
The classical pathway for the activation of complement is linked to antibody-mediated immunity because Ag-Ab complexes activate C1.
How much more IgG is circulating in the blood in the secondary response than in the primary response?
At peak secretion, approximately 1000 times more IgG is produced in the secondary response than in the primary response.
How does deletion differ from anergy?
In deletion, self-reactive T cells or B cells die; in anergy, T cells or B cells are alive but are unresponsive to antigenic stimulation.
Which cells of the immune system are attacked by HIV?
HIV attacks helper T cells.
What are the functions of the lymphatic and immune system?
Drain excess interstitial fluid, transport dietary lipids, and carry out immune responses.
What is the major difference between lymph and interstitial fluid?
Lack of resistance is also known as: