Midterm 1 Review Flashcards
Which of these develops from lymphoid stem cells?
Both T and B lymphocytes arise from lymphoid stem cells. Plasma cells are cloned from activated B lymphocytes.
What are functional characteristics of leukocytes?
positive chemotaxis, diapedesis, amoeboid motion
Which type of leukocyte provides protection against parasitic worms?
eosinophil
Which granular leukocytes act as our body’s bacteria killers and would dramatically increase in number during a bacterial infection?
Neutrophils
You are awaiting the white blood cell differential results for a patient who presented with a ruptured appendix and peritonitis. Which type of leukocyte do you expect to be most elevated over its normal value?
Neutrophils are the body’s bacteria slayers, so you would expect more of them to be present during a serious acute bacterial infection like the one your unfortunate patient has.
Which of the following mechanisms is NOT used to propel lymph through lymphatic vessels?
small, heart-like pumps
What is the unique structural modification in lymphatic capillaries that increases their permeability?
Minivalves
Which of the following promotes closure of the minivalves associated with lymph capillaries?
increasing pressure inside the lymph capillary. Minivalves will allow fluid in when external pressure exceeds internal pressure but will prevent fluid loss when the pressures are reversed.
Lymph from the right leg ultimately is delivered to which duct in the thoracic region?
The thoracic duct. It seems like odd plumbing, but lymph from the entire body below the diaphragm (both the right and left sides) enters the venous circulation via the thoracic duct.
Which of the following is NOT a function of the lymphatic system?
to return excess interstitial fluid to the bloodstream
to transport absorbed lipids from the small intestine to the bloodstream
to participate in gas exchange at capillaries
to carry pathogens towards lymph nodes
to participate in gas exchange at capillaries
Lymphatic capillaries are NOT found in __________.
Bone marrow. Lymphatic vessels are absent from bone marrow and teeth, as well as most of the central nervous system.
Which statement correctly describes the origin of lymph fluid?
Lymph is secreted into the lymph vessels.
Lymph is excess tissue fluid formed from plasma that has leaked from capillaries
Lymph is fluid collected from arteriovenous anastomoses.
Lymph is collected from fluid that accumulates in veins as blood slowly circulates back toward the heart.
Lymph is excess tissue fluid formed from plasma that has leaked from capillaries
As blood circulates through the body, nutrients, wastes, and gases are exchanged between the blood and the interstitial fluid. The hydrostatic and colloid osmotic pressures operating at capillary beds force fluid (plasma) out of the blood at the arterial ends of the beds and cause most of it to be reabsorbed at the venous ends. The fluid that remains behind in the tissue spaces, as much as 3 L daily, becomes part of the interstitial fluid. The lymphatic vessels collect this excess interstitial fluid (now called lymph) and return it to the bloodstream.
Which of these lymphoid organs is part of a collection of tissues called the mucosa-associated lymphoid tissues (MALT) and removes pathogens entering the pharynx (throat)?
The tonsils function to protect the throat and surrounding tissues from infection via the mouth and nose.
Which of these lymphoid organs is organized with trabeculae and compartments containing white pulp and red pulp?
The spleen is a large lymphoid organ containing areas of lymphocytes on reticular fibers (white pulp) and areas of reticular connective tissue cords and blood-filled sinuses (red pulp).
Which of the following lymphoid tissues/organs do(es) NOT contain reticular connective tissue?
The thymus is the only lymphoid organ that does not contain reticular connective tissue. The stroma of the thymus consists of epithelial cells rather than reticular fibers. These epithelial cells provide the physical and chemical environment in which T lymphocytes mature.
What region of the lymph node contains follicles filled with dividing B cells?
The cortex. The lymphoid follicles of the cortex contain germinal centers dominated by B cells, which produce antibodies against antigenic agents.
Which of the following is a role of lymph nodes?
They filter lymph.
They produce red blood cells.
They produce lymph.
They return lymph to circulation.
They filter lymph. Lymph nodes are rich with macrophages, B cells, and T cells; therefore, the lymph nodes are primed for activating the immune system. Structurally, lymph nodes have a capsule and medullary chords and sinuses that serve to filter lymph fluid.
Where is the spleen located?
The spleen is located in the left side of the abdominal cavity just beneath the diaphragm and is curled around the anterior aspect of the stomach. Its position leaves it vulnerable to damage in certain vehicle collisions.
Which tonsil is located in the posterior wall of the nasopharynx and is referred to as the adenoids if it is enlarged?
The pharyngeal tonsil is located in the posterior wall of the nasopharynx and is referred to as the adenoids if it is enlarged.
Which of the following organs or locations do(es) not contain MALT (mucosa-associated lymphoid tissue)?
Lymph nodes. Lymph nodes are not a component of MALT, as they are not associated with mucous membranes.
With what does our immune system coat pathogens to facilitate their capture and accelerate phagocytosis?
Opsonins. Opsonins are needed to provide a gripping point on some cells that have capsules or other defenses against adherence by phagocytes.
What characterizes the chemotaxis phase of phagocyte mobilization?
Neutrophils and other WBCs migrate up the gradient of chemotactic agents to the site of injury.
How do interferons protect against viral infection in healthy cells?
Interferons encourage the production of antiviral proteins. These antiviral proteins are coded in the cell’s DNA. These proteins can degrade viral RNA and interfere with viral protein synthesis.
Which of the following events is not directly associated with inflammatory responses?
antibody production. Inflammation is a component of the body’s innate defenses. Antibody-mediated (humoral) immunity is a component of adaptive defenses.
