Anatomy Exam 2 – Flashcards

The lymphatic system returns leaked fluid and plasma proteins that escape from the bloodstream to the blood. Hydrostatic and osmotic pressures in capillary beds combine in such a way that some fluid is lost by capillaries that cannot be regained by them. These fluids return to venous circulation through the lymphatic system.

small heart-like pumps There is no direct pumping action in the lymphatic system. Movement of fluid depends on factors such as gravity and body movement.

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.

Blood vessels Blood vessels are not a part of the lymphatic system. They are a part of the circulatory system.

The thymus The thymus is responsible for the maturation of T lymphocytes, and while it is large in youth, it tends to be reduced in size as the body ages.

The spleen The spleen harbors macrophages that ingest and recycle materials from erythrocytes that have aged or become damaged.

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.

True. Afferent vessels deliver lymph to the lymph node. The lymph then filters through the subcapsular sinus of the node and then into a number of smaller sinuses that cut through the node's cortex and lead into the medulla. Eventually, lymph exits the node via the hilum and is carried away by efferent vessels.

The spleen The spleen is an important lymphoid organ in immune surveillance and has an important role in its red blood cell recycling.

Peyer's patches: mature B cells Peyer's patches are lymphoid organs found in the wall of the distal portion of the small intestine.

tonsils Tonsils lack a complete capsule. The epithelium overlying tonsils invaginates deeply into their interior to form crypts where bacteria and particulate matter are trapped to be destroyed in the lymphoid tissue of the tonsils.

bone marrow and thymus Yes, the B lymphocytes are named B cells because they mature in the Bone marrow and the T lymphocytes are named T cells because they mature in the Thymus. This is also where they become immunocompetent.

white pulp of the spleen Yes, the white pulp is where lymphocytes are concentrated and the immune functions take place in the spleen.

deep in the cortex Yes, the T cells encounter antigens presented by dendritic cells in the deeper part of the cortex. The cortex is the outer area of the lymph node.

Peter's patches Yes, Peyer's patches are located in the small intestine, and they guard against bacteria from the large intestine.

thymus Yes, the relative size of the thymus as well as its function decreases with age. Thymic atrophy may be one reason the elderly are more susceptible to infection.

intact skin and mucous membranes The first line of defense against disease is intact skin and mucous membranes. If an antigen (pathogen) cannot enter the body, a secondary defense is unnecessary.

macrophages Macrophages, or "big eaters" perform most of the phagocytic activity in the body, ingesting bacteria, cellular debris, aging blood cells, and others.

edema (swelling) Edema is caused when release of fluids from blood vessels exceeds their uptake. Not only is blood flow increased to inflamed areas, but capillaries are made more permeable to fluid, resulting in loss of fluid from the blood and tissue swelling.

NK cells recognize abnormal or cancer cells by a specific antigen on their cell membrane. Correct answer. NK cells do not recognize abnormal or cancer cells by a specific antigen on their cell membrane. NK cells to do not have specific antigen receptors - like T cells do. NK cells look for the absence of normally occurring "self" proteins on infected or cancerous cells.

interferons Yes, interferons are antimicrobial proteins that interfere with viral replication. They are produced by a virus-infected cell. Although the infected cell will die, it sends out interferons that protect the neighboring cells from the virus.

The phagocytes recognize molecules on pathogens not normally found on body cells Yes, they use mannose and Toll-like receptors to bind to the molecules found on pathogens.

complement proteins Yes, the complement proteins can lyse microorganisms using the MAC (membrane attack complex) system to form pores, mark cells for phagocytosis (opsonization), and promote inflammation.

antibodies and complement proteins Yes, both antibodies and complement proteins can act as opsonins on bacteria.

System consisting of lymphatic vessels, lymph nodes, and lymph; drains excess tissue fluid from the extracellular space. The nodes provide sites for immune surveillance.

Diffusely distributed collections of lymphoid tissue in mucous membranes.

Pharyngeal tonsil

Lymph is the fluid inside lymphatic vessels. It enters lymphatic vessels from interstitial fluid. Interstitial fluid, in turn, is a filtrate of blood plasma

The right lymphatic duct receives lymph from the right upper arm and the right side of the head and thorax. The thoracic duct drains lymph from the rest of the body.

Lymph movement is driven by the contraction of adjacent skeletal muscles, pressure changes in the thorax during breathing, the pulsations of nearby arteries, and contraction of smooth muscle in the lymphatic vessel walls. (Valves in lymphatic vessels prevent backflow of lymph.)

Lymphoid follicles are solid, spherical bodies consisting of tightly packed reticular fibers and lymphoid cells, often with a lighter-staining central region. They are regions where B cells predominate.

Having fewer efferents causes lymph to accumulate in lymph nodes, allowing more time for its cleansing.

The spleen cleanses the blood, recycles breakdown products of RBCs, stores iron, stores platelets and monocytes, and is thought to be a site of erythrocyte production in the fetus.

MALT (mucosa-associated lymphoid tissue) is lymphoid tissue found in the mucosa of the digestive, respiratory, and genitourinary tracts. It includes tonsils, Peyer's patches, and the appendix.

cisterna chyli

reticular tissue

proliferating B lymphocytes

collect excess fluid from interstitial spaces

The milking action of skeletal muscle contraction Pressure changes in the thorax that result from breathing