1What are the three parts of the lymphatic system?
Lymphatic vessels, lymph, and lymph nodes
2What is the main function of the lymphatic system?
Returns leaked fluid to the bloodstream and supports immunity
3What is lymph?
Interstitial fluid that enters lymphatic vessels
4How much lymph is circulated daily?
~3 liters per day
5What happens once interstitial fluid enters lymphatic vessels?
It is called lymph
6What type of system are lymphatic vessels?
One-way system toward the heart
7What makes lymphatic capillaries unique?
They are more permeable than blood capillaries
8What can lymphatic capillaries absorb?
Proteins, debris, pathogens, and cancer cells
9What are minivalves?
Overlapping endothelial cells that allow one-way flow
10What are lacteals?
Lymphatic capillaries in the intestine that absorb fats
11What is chyle?
Fat-rich lymph
12What do lymphatic capillaries drain into?
Collecting lymphatic vessels
13What do collecting lymphatic vessels resemble structurally?
Veins
14What does the right lymphatic duct drain?
Right arm, right head, and right thorax
15What does the thoracic duct drain?
The rest of the body
16Where does lymph reenter the bloodstream?
Junction of internal jugular and subclavian veins
17What helps move lymph through vessels?
Muscle contraction, breathing, valves, arteries, smooth muscle
18What is lymphedema?
Localized swelling from blocked lymph flow
19What are lymphoid organs?
Organs that house immune cells
20What produces the stroma of lymphoid organs?
Reticular cells
21What is the primary function of lymph nodes?
Filter lymph and activate immune cells
22What shape are most lymph nodes?
Bean-shaped
23What surrounds a lymph node?
Fibrous capsule
24What are trabeculae?
Extensions of the capsule into the node
25What are the two main regions of a lymph node?
Cortex and medulla
26What cells dominate the cortex?
B cells
27What cells dominate the deep cortex?
T cells
28What are medullary cords?
Regions with lymphocytes and macrophages
29Where does lymph enter a lymph node?
Afferent lymphatic vessels
30Where does lymph exit a lymph node?
Efferent lymphatic vessels
31Why does lymph flow slowly through nodes?
Fewer efferent vessels
32What are buboes?
Swollen, inflamed lymph nodes
33How do cancerous lymph nodes usually feel?
Swollen but not painful
34What is the spleen’s main function?
Filters blood
35Where is the spleen located?
Left upper abdominal cavity
36What are the two regions of the spleen?
White pulp and red pulp
37What is white pulp?
Immune function area
38What is red pulp?
Removes old blood cells
39What is splenectomy?
Surgical removal of the spleen
40What happens if the spleen is removed?
Liver and bone marrow take over functions
41What is MALT?
Mucosa-associated lymphoid tissue
42What is the function of MALT?
Protect mucosal surfaces
43What are examples of MALT?
Tonsils, Peyer’s patches, appendix
44What do tonsils do?
Trap pathogens from food and air
45Where are Peyer’s patches found?
Small intestine
46What is the function of the appendix?
Immune defense in the gut
47What is the thymus?
Organ where T cells mature
48When is the thymus most active?
Childhood
49What are Hassall’s corpuscles?
Structures involved in regulatory T cell development
50What is the first line of immune defense?
Skin and mucous membranes
51What is the second line of immune defense?
Innate defenses
52What is the third line of immune defense?
Adaptive immunity
53What cells perform phagocytosis?
Neutrophils and macrophages
54What is opsonization?
Coating pathogens to enhance phagocytosis
55What are natural killer cells?
Cells that kill virus-infected and cancer cells
56What triggers inflammation?
Injury or infection
57What are the four signs of inflammation?
Redness, heat, swelling, pain
58What is chemotaxis?
Chemical attraction of immune cells
59What are interferons?
Antiviral signaling proteins
60What is the complement system?
Proteins that enhance inflammation and destroy microbes
61What is the membrane attack complex?
Protein complex that lyses microbes
62What causes fever?
Pyrogens acting on the hypothalamus
63How does fever help the body?
Slows pathogens and boosts repair
64What is adaptive immunity?
Specific immunity with memory
65What are antigens?
Substances that trigger immune responses
66What is a hapten?
Incomplete antigen
67What cells perform humoral immunity?
B cells
68What cells perform cell-mediated immunity?
T cells
69Where do B cells mature?
Bone marrow
70Where do T cells mature?
Thymus
71What are plasma cells?
Antibody-secreting B cells
72What are memory cells?
Long-lived cells that enable faster responses
73What is active immunity?
Body produces its own antibodies
74What is passive immunity?
Antibodies are received
75What is natural immunity?
Immunity from infection or maternal transfer
76What is artificial immunity?
Immunity from vaccines or injections
77What is the basic structure of an antibody?
Two heavy and two light chains
78What does the variable region do?
Binds antigen
79What does the constant region determine?
Antibody class
80What does IgM do?
Activates complement
81What does IgA do?
Protects mucosal surfaces
82What does IgG do?
Crosses placenta
83What does IgE do?
Mediates allergies
84What are monoclonal antibodies?
Lab-made antibodies for one antigen
85What is Type I hypersensitivity?
Allergies and anaphylaxis
86What is Type II hypersensitivity?
Cytotoxic antibody reactions
87What is Type III hypersensitivity?
Immune complex reactions
88What is Type IV hypersensitivity?
Delayed T-cell response