Blood, Lymph and Immunity Flashcards
1
Q
What are the three functions of blood?
A
- A transport system
- a regulatory system
- a defense system
2
Q
How does blood work as a transport system?
A
- O2 and nutrients to all living cells
- waste products to lung and kidney
- hormones from endocrine glands to target organs
- white blood cells from bone marrow to tissues
- platelets for clotting
3
Q
What are the regulatory functions of blood?
A
- body temperature: absorbs heat from active skeletal muscle; cools body temperature through skin surface; senses brain temperature regulators
- the pH (normal 7.35-7.45), ion compositions and volume of interstitial fluids –> homeostasis
4
Q
How dose blood work as a defense system?
A
- white blood cells –>phagocytosis
- antibodies –> attacks forgein organisms and compounds
- clotting factors and platelets
5
Q
What are anticoagulants?
A
substances that tie up clotting factors and prevent blood from clotting, (EDTA ties up calcium)
6
Q
What is serum?
A
the plasma - clotting proteins (in clotting: fibrinogen –> insoluble fibrin; clotting process also removes calcium ions)
7
Q
Describe blood volume?
A
blood volume (liters) = 7% of body weight (kilograms) in humans;
- adult male: 5 to 6 liters
- adult female: 4 to 5 liters
- dog: 7.2%
- cow: 7.7%
- sheep: 8.0%
- horse 9.7%
8
Q
How much blood can you lose?
A
the limit is about 25% of the total blood volume
8
Q
What is the main component of blood and what percent is it?
A
water, ~92%
9
Q
What percentage of blood do plasma proteins make up?
A
~7%
10
Q
What are the main plasma proteins and describe them?
A
- albumin (60%): transport lipids, steroid hormones
- globulines (35%): transport globulins (transport ions, hormones, lipids) and immunoglobulins (antibodies): IgG, IgA, IgM, IgE, IgD
- fibrinogen (4%): essential component of clotting system
- regulatory (<1%): enzymes, proenzymes, hormones
11
Q
What are the other solutes that make up blood?
A
- electrolytes: Na+, K+, Mg2+, Cl-, HCO3-, HPO42-, SO42-
- organic nutrients: lipids, glucose, amino acids
- organic wastes: urea, uric acid, creatinine, ammonium ions
- gasses: O2, CO2, N2
12
Q
What is included in extracellular fluid?
A
includes interstitial fluid and plasma
13
Q
Describe plasma
A
plasma does not equal interstitial fluid.
- similar in major plasma ions
- different in dissolved protein concentrations
- different in levels of respiratory gasses
14
Q
What are the formed elements?
A
red blood cells, platelets (thrombocytes), and white blood cells (leukocytes)
15
Q
What are red blood cells?
A
- red blood cells (RBCs) make up 99.9% of blood’s formed elements
- function: the transport of respiratory gasses (O2 and CO2)
- live about 120 days
16
Q
How do you measure red blood cells?
A
red blood cell count:
- reports the number of RBCs in 1 microliter of whole blood
- in millions: humans: 4.2-6.3; horse: 7; cow: 7; sheep: 11; pig: 7; dog: 7
- a single drop = 260 million
- total = 25 trillion = 1/3 of all cells of human body
- 1000 RBC : 1 WBC
17
Q
What is hematocrit?
A
means packed cell volume (PCV)
- percentage of RBCs in centrifuged whole blood
18
Q
What is the structure of a RBC?
A
- membranous sac (65% water, 35% solids)
- a biconcave disc: thin in middle and thicker at edge
- lost most organelles, including nuclei. retain only cytoskeleton
- can not divide or synthesize structural proteins. Can not repair themselves
19
Q
What is the importance of RBC shape and size?
A
- high surface-to-volume ratio:
- quickly absorbs and releases oxygen - discs form stacks
- smoothes flow through narrow blood vessels - discs bend and flex entering small capillaries
- 7.8 micrometers RBC passes through 4 micrometer capillary - a short diffusion distance
20
Q
What is hemoglobin?
A
- A protein molecule, transports respiratory gases
- HB accounts > 95% of solids, 280 million Hb per RBC
21
Q
Describe the makeup of hemoglobin.
A
Has 4 globular protein subunits
- each with 1 molecule of heme
- each heme contains 1 iron ion
22
Q
What is the importance of iron on hemoglobin?
A
iron ions easily form a weak, easily reversible binding with an oxygen
23
Q
What is the difference between normal hemoglobin and fetal hemoglobin?
A
fetal hemoglobin binds to O2 more easily and “steals” O2 from mother
24
Where does hemoglobin in RBCs transport to?
- oxygen from lungs to peripheral tissues
- carbon dioxide from tissues to lungs
25
What is oxyhemoglobin?
- bright red
- is oxygen binded to an iron
- is taking oxygenated blood away from the lungs
- works under high pressure
26
What is deoxyhemoglobin?
- dark red
- is deoxygenated blood
- taking blood back to the heart and lungs
- the amount of oxygen bound to HB depends on the oxygen content of the plasma
27
What is the relevance of anemia?
- when hematocrit or hemoglobin levels are below normal
- low hematocrit: blood loss, blood destruction, decreased red blood cell production
- to little Hb: mainly due to deficiency of one or the substances needed to synthesize heme or globun
28
What is polycythemia?
an increase above normal in the number of RBCs due to dehydration
29
What determines the blood types in humans?
surface antigens of RBCs (agglutinogens)
- antigen: substance that trigger an immune response
30
Describe the surface antigens of human RBCs
Human RBCs have > 50 agglutinogens (integral membrane glycoproteins or glycolipids), three are important: A, B, and Rh (D)
31
Describe the antibodies in plasma
globular proteins that bind to specific "foreign" antigens and promote their destruction or removal from the body
32
What are the 4 basic blood types?
A, B, AB, and O
33
What are the blood types in dogs?
- DEA 1.1 positive
- DEA 1.1 negative
- Universal
34
What are the blood types of cats?
A, B, AB
35
What are white blood cells also called?
leukocytes
36
What are white blood cells made up of?
do not have hemoglobin, have nuclei and other organelles
37
What are the functions of white blood cells?
- defend against pathogens
- remove toxins and wastes
- attack abnormal cells
38
Describe granular leukocytes (granulocytes)
- have granules in their cytoplasm
- based on staining
39
What are the granular leukocytes and what are their stains?
- basophil: blue granules
- neutrophil: neither blue nor red
- eosinophil: red granules
40
Describe nongranular leukocytes (agranulocytes)
- no granules in their cytoplasm
- based on their specific functions
41
What are the nongranular leukocytes and what are their functions?
- lymphocyte: T cells, B cells, NK cells
- monocyte
42
What are the characteristics of WBCs?
- capable of amoeboid movement
- can migrate out of the blood stream (margination and diapedesis)
- positive chemotaxis: neutrophils, eosinophils, and monocytes are capable to phagocytosis
43
Which WBC are microphages?
neutrophils and eosinophils
44
Which WBC are macrophages?
monocytes that moved out the bloodstream
45
Describe neutrophils
- granules contain lysosomal enzymes and bactericidal compounds (hydrogen peroxide and superoxide)
- very dense, segmented nucleus that forms 2-5 lobes --> also called polymorphonuclear leukocytes (PMNs)
46
What is the function of neutrophils?
1st line of defense (quick response)
- phagocytosis of small pathogenic organisms
- hydrogen peroxide kills bacteria
47
What is the lifespan of neutrophils?
hours - 3 days
48
Describe eosinophils
- large granules stain red with eosin
- bilobed nucleus
49
What are the functions of eosinophils?
- attack objects (bacteria, protozoa, or cellular debris) by phagocytosis and exocytosis of toxic compound (nitric oxide and cytotoxic enzymes)
- defend against large multicellular parasites
- release anti inflammatory substances in allergic reactions
50
What is the lifespan of eosinophils?
10 - 12 days
51
Describe basophils
- rare and smaller
- dense granules stain deep purple of blue with basic dye
- nucleus generally cannot be seen
52
What are the functions of basophils?
- enhance inflammatory response by:
- release histamine (dilates blood vessels)
- release heparin (prevents blood clotting)
53
What is the lifespan of basophils?
hours - 3 days
54
Describe monocytes
- largest (twice the diameter of a RBC)
- spherical
- nucleus is large and tends to be oval or kidney bean shaped
55
What are the functions of monocytes?
- enter peripheral tissues to become a tissue macrophage (major and aggressive phagocytes)
- release chemicals to attract and stimulate other phagocytic cells
- secrete substances that lire fibroblasts into the region to produce scar tissue
56
What is the lifespan of monocytes?
months
57
Describe lymphocytes
- slightly larger than RBC
- round and large nucleus, often look like nuclei without cytoplasm
- migrate in and out of blood
- mostly in connective tissues and lymphatic organs
58
What are the types of lymphocytes?
T cells, B cells, NK cells
59
What do T cells do?
cell-mediated immunity: provide "killer" cells to directly attack foreign invaders
60
What do B cells do?
humoral immunity: production and distribution of antibodies
61
What do NK cells do?
immune surveillance: the detection and subsequent destruction of abnormal tissue cells
62
What is the lifespan of lymphocytes?
days to years
63
What is the ratio of WBCs to RBCs?
RBCs outnumber WBCs 1000:1
64
What is differential count?
the number of each type of cell in a sample of 100 WBCs
65
Why do WBC counts change?
changes in infections, inflammation, and allergic reactions
66
Describe platelets (thrombocytes)
- cell fragments: not complete cells. Megakaryocyte sheds cytoplasm to produce ~4000 platelets in a lifetime
- cytoplasm contains very small pink staining granules which contain some of the clotting factors
67
What are the functions of platelets (thrombocytes)
1. release important clotting chemicals
2. temporarily patch damaged vessel walls
3. actively contract tissue after clot formation
68
What is another name for platelets?
thrombocytes
69
What is the lifespan of platelets (thrombocytes)?
7 - 12 days
70
What is hemostasis?
the process by which blood is prevented from leaking from damaged blood vessels. At the same time, it establishes a framework for tissue repairs.
71
What are the three phases of hemostasis?
- vascular phase
- platelet phase
- coagulation phase
72
Describe the vascular phase
- a cut triggers vascular spasm
- smooth muscles contract
- endothelial cell membranes become "sticky"
73
Describe the platelet phase
- attachment of platelets to exposed surfaces
- platelet aggregation (attachment) to form a platelet plug
- begin within 15 seconds
74
Describe the coagulation phase?
- begins 30 seconds or more
- blood clotting (coagulation): involves a series of steps, converts circulating fibrinogen into insoluble fibrin, fibrin + trapped blood cells = blood clot
- clotting factors: Ca2+ and 11 proteins
- fibrinolysis: as the repairs proceed, the clot gradually dissolves by the enzyme
75
What is hematopoiesis?
- the entire process of all blood cell production
- a continuous process
76
Where does hematopoiesis take place in early fetus and adults?
- in early fetus: liver and spleen
- in adults: red bone marrow, the only site of red blood cell production and the primary site of white blood cell formation
77
What determines the pathways of hematopoiesis?
the chemical or physiological stimulus determines the pathways; one-way process
78
What is the relevance of blood cancer?
- leukemia: increase white blood cells in blood. Lymphocytic leukemia: too many lymphocytes. Myeloid leukemia: increase myeloid cells, decrease in white blood cells, red blood cells, and platelets
- lymphoma: cancer of the lymph stem
- myeloma: cancer of the plasma cells in bone marrow
79
What are the 4 parts of the lymphatic system?
1. Lymph
- a fluid similar to plasma
- does not have plasma proteins
2. lymphatic vessels (lymphatics)
- network that carries lymph from peripheral tissues to the venous system
3. lymphoid tissues and lymphoid organs
- found throughout the body
- connected to lymphatic vessels and contain large numbers of lymphocytes
4. lymphocytes: T-cells. B-cells, and NK cells
80
What are the functions of the lymphatic system?
- the production, maintenance, and distribution of lymphocytes --> immune function
- the return of fluid and solutes from peripheral tissues to the blood
- also transports hormones, nutrients, and waste products
81
Describe lymphatic capillaries (terminal lymphatics)
- originate as blink pockets
- flattened or irregular outline in sectional view
82
Describe lymphatic vessels (lymphatics)
- microscopic lymphatic capillaries merge to form lymphatic vessels
83
Describe lymphatic trunks
- formed by convergence by superficial and deep lymphatics
84
Describe lymphatic ducts
- converged by trunks, empty into the subclavian veins
85
Describe the order of lymph flow
afferent lymphatics --> subcapsular sinus --> outer cortex (B cells) --> deep cortex (T cells) --> medulla (B cells, macrophages) --> efferent lymphatics
86
What is the function of lymph nodes?
like a kitchen water filter, it filters and purifiers lymph before lymph reaches the venous circulation. It removes debris, pathogens, and 99% of antigens
87
What is the structure of the spleen?
- the largest lymphoid organ, "tongue" shaped
internal organization
- red pulp: blood vessels and storage space (sinuses)
- white pulp: localized areas of lymphoid tissues
88
What are the functions of the spleen?
- blood storage in red pulp
- defense: remove foreign materials from circulation by macrophages
- remove dead, dying, and abnormal RBCs
89
Describe the structure of the thymus
- laying on either side of the trachea
- two thymic lobes (lobules)
- each lobule consists of: cortex and medulla
- lymphocytes: divide in the cortex, T cells migrate into the medulla, mature T cells leave thymus by medullary blood vessels
90
What are the functions of the thymus?
- final site of T-cell development
- secrete a group of hormones (thymosin) to stimulate T-cell development
91
What is gut-associated lymphoid tissue (GALT) and what does it include?
an innate system in the gastrointestinal system
includes:
- tonsils
- Peyer's patches: organized lymphoid follicles
- specialized M cells: transport microbes from the intestine to other side for macrophages
92
What is the immune system?
all body cells and tissues involved in production of immunity, not just lymphatic system
93
What are the functions of the immune system?
to protect animals from anything that could cause disease or damage:
- phagocytosis and destruction of foreign cells
- lysis of foreign cell membranes
- inactivation of pathogenic organisms or chemical substances
- precipitation or clumping (agglutination) of cells or molecules
recognize and differentiate between "self" and "foreign invaders"
94
What are pathogens?
microscopic organisms that cause disease:
- viruses
- bacteria
- fungi
- parasites
each attacks in a specific way
95
What is immunity?
The ability to resist infection and disease
96
What is nonspecific immunity (innate immunity)?
Do not distinguish one type of threat from another
97
What is specific immunity (acquired immunity)?
- protect against particular threats
- both nonspecific and specific immune response are complementary and must function normally
98
Name the 7 parts of nonspecific immunity
1. physical barrier
2. phagocytes
3. immunological surveillance
4. interferons
5. complement system
6. inflammation
7. fever
99
Describe the physical barrier
keeps hazardous materials outside the body by:
- epithelial covering barrier (skin)
- specialized accessory structures and secretions of epithelial cells (hair, secretions: flush surface, contain bactericidal chemicals)
100
Describe the phagocytes of nonspecific immunity
"first line" of cellular defense
- microphages: neutrophils and eosinophils
- macrophages: fixed macrophages and free macropahges
attack and remove dangerous microorganisms
- engulf a pathogen
- bind to or remove a pathogen with assistance by other cells
- destroy its target by releasing toxic chemicals
101
Describe immunological surveillance
Natural killer (NK) cells recognize and destroy abnormal cells by detecting the antigens on the cell membrane of abnormal cells and lyse the cell by forming pores with perforin
102
Describe interferons
- small proteins released by activated lymphocytes and macrophages and by tissues cells infected with viruses
functions:
- trigger production of antiviral proteins in normal cells
- antiviral proteins: do not kill viruses, block replication in cell
103
Describe the complement system
- 11 complement proteins (C)
- complements, or supplements the action of antibodies
functions: destruction of target cell membranes by forming the membrane attack complex (MAC) which creates a pore for cell lysis
104
Describe inflammation
the first step in the healing process, characterized by:
1. swelling
2. redness
3. warmth
4. pain
5. some loss of function
105
What does histamine do?
increases capillary permeability
106
What does heparin do?
inhibits clotting
107
What are the functions of inflammation?
1. temporary repair and barrier against pathogens
2. retards spread of pathogens into surrounding areas
3. mobilization of local and systemic defenses
108
What are pyrogens?
- proteins that can reset body's thermostat and raise body temperature
- pathogens, bacterial toxins, and antigen - antibody complexes
109
Describe a fever
uses pyrogens
within limits, for each 1 degree celsius rise in temperature, metabolism rate jumps by 10%.
- quicker mobilization of tissue defenses and acceleration of repair process
110
What is specific resistance (immunity)?
- responds to specific antigens
- with coordinated action of T cells and B cells
111
What are the 4 properties of specific immunity?
1. specificity: responds only to a specific antigen
2. versatility: animal body is ready to confront many antigen at any time, resulted from the large diversity of lymphocytes and antibodies in the body
3. memory: if an antigen enters the body a second time, a memory of the antigen causes the immune response to occur more quickly
4. tolerance: immune system ignores "normal" antigens
112
Describe T cells
thymus-dependent, 80% of circulating lymphocytes
113
What do cytotoxic T cells (Tc) (killer T cells) do?
- attack cells physically by releasing perforin
- produce cell-mediated immunity
114
What do Helper T cells (TH) do?
- secrete cytokines to stimulate both T cells and B cells
- most numerous T cells
115
What do suppressor T cells (Ts) do?
inhibit T cell and B cell activities
116
What does cell-mediated immunity involve?
involves close physical contact between activated Tc cells and foreign, abnormal, or infected cells
117
What do B cells do?
-responsible for antibody-mediated immunity
- attack antigens by producing specific antibodies
- millions of populations, each with different antibody molecules
118
Describe the structure of an antibody
2 parallel pairs of polypeptide chains
- 1 pair of heavy chains
- 1 pair of light chains
each chain contains:
-constant segments: IgG, IgE, IgD, IgM, or IgA
- variable segments: contain antigen binding sites, determines the specificity of the antibody, ~ 100 million types of antibodies
119
Describe the IgG antibody
- 80% of all antibodies
- mainly in plasma
120
Describe the IgE antibody
- attaches to exposed surfaces of basophils and mast cells
- important in allergic response
121
Describe IgD antibodies
- on surface of B cells
- involved in B cell activation
122
Describe IgM antibodies
- first class of antibody secreted after an antigen arrives
- effective in forming immune complexes
123
Describe IgA antibodies
- primarily in glandular secretions: mucus, tears, saliva
124
What are the seven actions of antibodies?
1. neutralization of antigen binding sites
2. precipitation and agglutination: formation of immune complex
3. activation of complement
4. attraction of phagocytes
5. opsonization: increasing phagocyte efficiency
6. stimulation of inflammation
7. prevention of bacterial and viral adhesion
125
What is specific resistance (immunity)?
responds to threats on an individualized basis
126
What is acquired immunity?
produced by prior exposure or antibody production
127
What is innate immunity?
Genetically determine -- no prior exposure or antibody production involved
128
What is active immunity?
produced by antibodies that develop in response to antigens (immune response)
129
What is passive immunity?
produced by transfer of antibodies from another person
130
What is naturally acquired immunity?
develops after exposure to antigens in environment
131
What is induced active immunity?
develops after administration of antigen to prevent disease
132
What is induced passive immunity?
conferred by administration of antibodies to contract infection
133
What is natural passive immunity?
conferred by transfer of maternal antibodies across placenta or in breast milk
134
