Chapter 21: Lymphoid & Immune Systems Flashcards
1
Q
What are microorganisms that reside on and in the human body?
A
microbiome
2
Q
not an organ system, but a cell population that inhabits all organs and defends the body from agents of disease
A
immune system
3
Q
swelling due to interference in lymphatic drainage
A
lymphedema
4
Q
functions of lymphoid system
A
fluid recovery
immune surveillance
lipid absorption
5
Q
fluid recovery
A
Fluid continually filters from the blood capillaries into the tissue spaces
Blood capillaries reabsorb 85% and the rest (15%) enters the lymphatic vessels
6
Q
immune surveillance
A
Excess filtered fluid picks up foreign cells and chemicals from the tissues
Passes through lymph nodes where immune cells stand guard against foreign matter
Activates a protective immune response
7
Q
lipid absorption
A
Lacteals in small intestine absorb dietary lipids that are not absorbed by the blood capillaries
8
Q
3 layers of lymphatic vessels
A
tunica interna, tunica media, tunica externa
9
Q
tunica interna
A
endothelium and valves
10
Q
tunica media
A
elastic fibers, smooth muscle
11
Q
A
12
Q
tunica externa
A
thin outer layer
13
Q
what do lymphatic trunks form when they converge?
A
two collecting ducts (right and thoracic duct)
14
Q
right lymphatic duct
A
receives lymph from right arm, right side of head and thorax; empties into right subclavian vein
15
Q
thoracic duct
A
larger and longer, begins as a sac in abdomen called the cisterna chyli; receives lymph from below diaphragm, left arm, left side of head, neck, and thorax; empties into left subclavian vein
16
Q
summary of path from tissue fluid back to bloodstream
A
Lymphatic capillaries → collecting vessels → 11 lymphatic trunks → two collecting ducts → subclavian veins
17
Q
glymphatic system
A
lymphatic-resembling vessels associated with neuroglia
Arteries that penetrate the brain tissue are surrounded in perivascular tunnels containing a mix of cerebrospinal fluid (CSF) and interstitial fluid (ISF)
Removal of beta-amyloid protein associated with Alzheimer disease
18
Q
CSF-ISF composition is regulated by
A
astrocytes
19
Q
neutrophils
A
antibacterial
20
Q
natural killer cells (NK)
A
lymphocytes that attack and destroy infected host cells and cancerous cells
21
Q
T cells
A
mature in thymus
22
Q
B cells
A
activation causes proliferation and differentiation into plasma cells that produce antibodies
23
Q
macrophages
A
large phagocytic cells; are antigen-presenting cells (APCs): they display antigens on surface to alert other immune cells
24
Q
dendritic cells
A
APCs found in skin, mucous membranes, and lymphoid organs
25
lymphoid tissues
aggregations of lymphocytes in the connective tissues of mucous membranes and various organs
26
diffuse lymphoid tissue
lymphocytes are scattered (not densely clustered)
27
In mucous membranes, diffuse lymphoid tissue is called
MALT
28
lymphoid nodules (follicles)
lymphocytes and macrophages gather in dense masses
29
primary lymphoid organs
- red bone marrow and thymus
- Sites where T and B cells become immunocompetent
30
secondary lymphoid organs
- lymph nodes, tonsils, and spleen
- Locations where immunocompetent cells migrate and populate
31
immunocompetent
able to recognize and respond to antigens
32
red bone marrow
- soft, loosely organized, highly vascular material separated from osseous tissue by endosteum of bone
-Involved in hematopoiesis (blood formation) and immunity
33
what do blood cells do as they mature in the red bone marrow?
they push their way through the reticular and endothelial cells to enter the sinus and flow away in the bloodstream
34
thymus
- has fibrous capsule gives off trabeculae (septa) that divide the gland into several lobes
- involved in T cell development
35
what secretes signaling molecules thymosin, thymopoietin, thymulin, interleukins, and interferon
thymic epithelial cells
36
lymph nodes
bean-shaped structures that cleanse lymph and are sites of lymphocyte activation
37
parenchyma is divided into what?
cortex and medulla
38
germinal centers in cortex
where B cells multiply and differentiate into plasma cells
39
afferent lymphatic vessels
lead INTO the node along its convex surface
40
efferent lymphatic vessels
Lymph leaves the node
41
cervical nodes
in neck
42
axillary nodes
in armpit
43
thoracic nodes
in thoracic cavity, especially mediastinum
44
abdominal nodes
in posterior abdominopelvic wall
45
Intestinal and mesenteric nodes
in mesenteries and near appendix and intestines
46
inguinal nodes
in groin
47
popliteal nodes
back of knee
48
Lymphadenitis
(localized) swollen, painful lymph node responding to foreign antigen
49
Lymphadenopathy
(Generalized) collective term for all lymph node diseases
50
metastasis
cancerous cells break free from original primary tumor, travel to other sites in the body and establish new tumors
51
cancerous nodes are usually?
swollen, firm, and painless
52
tonsils
- patches of lymphoid tissue located at the entrance to the pharynx
- Guard against ingested or inhaled pathogens
- Incomplete fibrous capsule
53
3 main sets of tonsils
pharyngeal tonsil (adenoids), palatine tonsils, lingual tonsils
54
tonsillitis
acute inflammation of palatine tonsils
55
pharyngeal tonsil (adenoids)
on wall of pharynx
56
palatine tonsils
at posterior margin of oral cavity
57
lingual tonsils
concentrated on each side of base of tongue
58
spleen
body's largest lymphoid organ
59
red pulp
sinuses fulled with erythrocytes
60
white pulp
lymphocytes, macrophages surrounding small branches of splenic artery
61
functions of spleen
- erythrocyte graveyard
- blood cell production in fetus
- Stabilizes blood volume through plasma transfers
- maintains army of monocytes for release when needed
62
what is highly vascular and vulnerable to trauma and infection?
spleen
63
ruptured spleen requires?
splenectomy (this leaves person susceptible to future infections and premature death)
64
pathogens
agents capable of producing disease, including viruses, bacteria, fungi, and other microbes
65
first line of defense
skin and mucous membranes, which serve as barriers
66
second line of defense
protections against pathogens that break the skin, mucous membrane barriers
67
examples of second line defenses
Leukocytes and macrophages, antimicrobial proteins, natural killer cells, fever, and inflammation
68
third line of defense
adaptive immunity, mechanisms that defeat a specific pathogen and leave the body with a memory of it
69
inmate immunity
- defenses we are born with (innate); protect us from broad spectrum of disease agents
- local effect
- nonspecific
- lacks memory
70
adaptive immunity
defenses against specific pathogens, developed only upon exposure (adaptive), and maintains immune memory
71
innate immunity contains
external barriers, antibacterial proteins, NK cells
72
acid mantle
thin film of lactic and fatty acids from sweat and sebum that inhibits bacterial growth
73
Dermcidin, defensins
peptides in skin that kill microbes
74
external barriers
- first line of defense
- protective features of the skin
- presence of lysozyme and acid mantle
75
lysozymes
enzyme that destroys bacterial cell walls
76
antimicrobial proteins contain
interferons and complement system
77
interferons
serve as an "alarm" to nearby cells
78
complement system
group of 30 or more globular proteins that contribute to both innate immunity and adaptive immunity
79
NK cells
perforates cell and contributes to cell lysis
80
fever
- abnormal elevation of body temp
- results from trauma, infections, drug reactions, and brain tumors
81
febrile
pertaining to fever
82
defense mechanisms of fever
- Promotes interferon activity
- Elevates metabolic rate and accelerates tissue repair
- Inhibits reproduction of bacteria and viruses
83
reye syndrome
serious disorder in children younger than 15 following an acute viral infection such as chickenpox or influenza (aspirin use)
84
inflammation
- local defensive response to tissue injury, including trauma and infection
- includes numerous cytokines
85
cardinal signs of inflammation
Redness, swelling, heat, pain
86
purpose of inflammation
- Limit spread of pathogens, then destroys them
- Remove debris from damaged tissue and initiate tissue repair
87
cytokines
small proteins that function in chemical communication between cells
88
inflammation tissue cleanup and repair
- involves monocytes, which arrive in 8 to 12 hours and become macrophages
- Edema contributes to tissue cleanup
- pus and abscess
89
pus
yellow accumulation of dead neutrophils, bacteria, cellular debris, and tissue fluid
90
abscess
accumulation of pus in a tissue cavity
91
adaptive immunity serves as which line of defense?
third
92
which has systemic effect, specific, and records a memory?
adaptive immunity
93
two types of adaptive immunity
- cellular T cell immunity
- humoral B cell immunity
94
cellular T cell immunity
- Lymphocytes directly attack and destroy foreign cells or diseased host cells
- Rids the body of pathogens that reside inside human cells where they are inaccessible to antibodies
- Also acts against parasitic worms, cancer cells, and transplanted cells
95
humoral B cell immunity
- Mediated by antibodies that do not directly destroy a pathogen but tag it for destruction
- Effective against extracellular viruses, bacteria, yeasts, protozoans, and molecular (noncellular) disease agents such as toxins, venoms, and allergens
96
natural active immunity
Production of one’s own antibodies or T cells as a result of infection or natural exposure to antigen
97
artificial active immunity
Production of one’s own antibodies or T cells as a result of vaccination against disease
98
vaccine
consists of dead or attenuated (weakened) pathogens that stimulate the immune response without causing the disease
99
natural passive immunity
Fetus acquires antibodies from mother through placenta, baby acquires them during breast-feeding
100
artificial passive immunity
- Temporary immunity that results from the injection of immune serum (antibodies) from another person or animal
- Emergency treatment for snakebite, botulism, tetanus, rabies, and other diseases
101
antigen (Ag)
- any molecule that can bind to antibody
- have large molecular weights
- Proteins, polysaccharides, glycoproteins, glycolipids
102
Epitopes (antigenic determinants)
certain regions of an antigen molecule that stimulate immune responses
103
Haptens (incomplete antigens)
- too small to be antigenic in themselves
- May trigger immune response by combining with a host molecule, creating a complex that the body recognizes as foreign
- Cosmetics, detergents, industrial chemicals, poison ivy, animal dander, penicillin
104
Antibodies (Abs), or immunoglobulins (Igs)
- defensive proteins that play a variety of defensive roles
- found in membranes of immune cells and some are soluble antibodies
105
IgA
- monomer in plasma; dimer in mucus, saliva, tears, breast milk, and intestinal secretions
- Provides passive immunity to newborns
106
IgD
- monomer; B cell transmembrane antigen receptor
- Functions in B cell activation by antigens
107
IgE
- monomer; bound to receptors on basophils, mast cells
- Stimulates release of histamine and other chemical mediators of inflammation and allergy
- Stimulates eosinophil defensive actions against parasites
108
IgG
- monomer; constitutes 80% of circulating antibodies
- Predominant antibody in secondary immune response, capable of complement fixation, can cross placenta to fetus
109
IgM
- pentamer in plasma and lymph
- Predominant antibody in primary immune response, strong agglutinating and complement-fixing abilities
110
3 types of lymphocytes
Nk cells, B cells, T cells
111
T cells
- birth in bone marrow
- training and mature in thymus
112
APCs include
dendritic cells, macrophages, and B cells
113
functions of APCs
- Act as cell “identification tags” that label every cell of your body as belonging to you
- Structurally unique for each individual, except for identical twins
114
4 classes of T cells
cytotoxic cells, helper cells, regulatory cells, and memory cells
115
cytotoxic T cells
carry out attack
116
helper T cells
promote activities of other immune cells
117
regulatory T cells
limit the immune response
118
memory cells
responsible for memory in cellular immunity
119
general stages of response
recognition, attack, memory
120
MHC 1 proteins
occur on all nucleated cells, internal peptides are presented on cell surface
121
MHC 2 proteins
occur on APCs, external (phagocytosed, foreign) antigens are presented on cell surface
122
MHC restriction
cytotoxic T cells respond only to MHC-1 proteins, helper T cells respond only to MHC-2 proteins
123
what are the only T cells that attack other cells?
cytotoxic T cells
124
perforin and granzymes
kill cells in the same manner as NK cells
125
interferons in attack
inhibit viral replication; recruit and activate macrophages
126
tumor necrosis factor (TNF)
aids in macrophage activation and kills cancer cells
127
neutralization
masking active regions of an antigen (toxin, virus, microbial cell)
128
complement fixation
activating complement by the classical pathway
129
agglutination
clumping of enemy cells, immobilizing them; clump cleared by phagocytes
130
precipitation
antigen molecules (not whole cells) are clumped by antibodies; clumps cleared by phagocytes
131
primary response in memory
- immune reaction brought about by the first exposure to an antigen
- protective antibodies delayed for 3 to 6 days while naive B cells multiply and differentiate into plasma cells
- As plasma cells produce antibodies, the antibody titer (level in the blood plasma) rises
- leaves one with an immune memory of the antigen
132
Secondary (anamnestic) response
- immune response when re-exposed to the same antigen
- Response is so rapid that the antigen has little chance to exert a noticeable effect on the body
- no illness results
133
hypersensitivity
an excessive immune reaction against antigens that most people tolerate
134
Alloimmunity
reaction to transplanted tissue from another person
135
Autoimmunity
abnormal reactions to one’s own tissues
136
allergies
reactions to environmental antigens (allergens)
137
autoimmune diseases
- failures of self-tolerance
- Immune system does not correctly distinguish self-antigens from foreign ones
- Produces autoantibodies that attack body’s own tissues
138
Severe combined immunodeficiency disease (SCID)
hereditary lack of T and B cells
139
Acquired immunodeficiency syndrome (AIDS)
- Nonhereditary diseases contracted after birth
- Disease caused by (HIV)
- HIV invades helper T cells, macrophages, and dendritic cells by “tricking” them to internalize viruses by receptor-mediated endocytosis
- host is vulnerable to opportunistic infections
140
HIV is a retrovirus which means it
uses reverse transcriptase to convert its RNA genome into DNA, which can then insert into host cell DNA
