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.
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.
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 function of the spleen?
Immune functions, destruction of blood-borne pathogens, removal of ruptured, worn out, or defective blood cells and platelets, storage of platelets, and production of blood cells during fetal life.
What are the physical factors in the first line of defense?
Epidermis of skin, mucous membranes, mucus, hairs, cilia, lacrimal apparatus, saliva, urine, defecation, and vomiting.
What are the chemical factors in the first line of defense?
Sebum, lysozyme, gastric juice, and vaginal secretions.
What makes up the second line of defense?
Antimicrobial substances, natural killer cells and phagocytes, inflammation, and fever.
Which anti-microbial substances promote cytolysis, phagocytosis and inflammation?
What induces vasodilation and permeability (increased fluid flow) to an infection site?
Histamine, kinins, prostaglandins, leukotrienes, and complement.
To become activated, what requires being bound to a foreign antigen AND simultaneous costimulation?
The inability of the immune system to protect the body from a pathogen causes
The ability of an antigen to react specifically with the antibodies or cells it has provoked is called
Which type of adaptive immunity will result from intravenous injection of immunoglobulins?
Artificially acquired passive immunity
Which type of adaptive immunity will result from mother-to-baby IgA transfer via breast feeding?
Naturally acquired passive immunity
Large clusters of lymph nodes occur in which regions?
Near the mammary glands and in the axillae and groin.
True or False: The lymphatic capillaries function to absorb the excess protein-containing interstitial fluid and return it to the bloodstream.
True or False: The cisterna chyli collects lymph from the lumbar trunks draining the upper limbs and from the intestinal trunk draining the digestive organs.
Both lymph and venous blood flow are heavily dependent on ________.
Skeletal muscle contractions and differences in thoracic pressures due to respiratory movement
What effect does age have on the size of the thymus?
The thymus initially increases in size and then decreases in size from adolescence through old age.
What is the correct sequence of events in phagocytosis?
Chemotaxis, adherence, ingestion, digestion, killing
True or False: When tissues are inflamed, lymphatic capillaries develop openings that permit uptake of large particles such as cell debris, pathogens, and cancer cells.
In clonal selection of B cells, which substance is responsible for determining which cells will eventually become cloned?
The primary immune response has a large lag due to what?
While B cells proliferate and differentiate into plasma cells.
Lymph capillaries are absent in which tissues?
Avascular tissues (cartilage, epidermis, cornea of the eye), the central nervous system, portions of the spleen, and red bone marrow.
True or False: The causative agent in acquired immune deficiency syndrome (AIDS) is a virus that recognizes CD4 proteins.
Which lymphatic structure drains lymph from the right upper limb and the right side of the head and thorax?
Right Lymphatic Duct
Innate immune system defenses include ________.
Physical factors, chemical factors, antimicrobial substances, natural killer cells, phagocytes, inflammation, and fever.