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Fig. 14.1-1Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
(a)
Tonsils
Cervicallymph node
Inguinallymph node
Spleen
Lacteals inintestinal wall
Thoracicduct
Subclavianveins
Bonemarrow
Lymphatic vessel(transports lymph)
Mammaryplexus
Axillarylymph node
Thymus
Right lymphaticduct
Thoracic duct
Fig. 14.2
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Fluid enteringlymphaticcapillary
Tissue cells
Lymphaticcapillary
To venous system (b)
(a)
Overlappingepithelialcells
Valve open(lymph flowsforward)
LymphValve closed(backflow of lymphis prevented)
Fluid enteringlymphatic capillary
Venule(to heart)
Bloodcapillary
Arteriole(from heart)
Direction of lymphflow in capillary
Fig. 14.1
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
(b)(a)
Area drained bythoracic duct
Area drained byright lymphaticduct
Tonsils
Cervicallymph node
Inguinallymph node
Spleen
Lacteals inintestinal wall
Thoracicduct
Subclavianveins
Bonemarrow
Lymphatic vessel(transports lymph)
Mammaryplexus
Axillarylymph node
Thymus
Right lymphaticduct
Thoracic duct
Fig. 14.3Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Pharyngeal tonsil
Palatine tonsil
Lingual tonsil
Fig. 14.4
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
VeinArtery
Efferent lymphatic vesselcarrying lymph away fromthe lymph node
Trabecula
Capsule
Afferent lymphatic vesselcarrying lymph to thelymph node
Cortex
Lymphatic tissue
Lymphatic sinuses
Germinal centerLymphatic nodule
Fig. 14.5
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
(a) (b) Capsule
Trabecula
Splenic arterySplenic vein
Branch ofsplenicartery
Branch ofsplenicvein
Red pulp
White pulp
Fig. 14.6-1Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
(a)
Heart
Adiposetissue
Thymus
Trachea
Lymphnodes
Fig. 14.7 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1
12
2
3
3
44
5
5
6
6
7
7
8
8
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9
Lymphatic capillaries remove fluid from tissues. Thefluid becomes lymph (see figure 14.2a).
Lymph flows through lymphatic vessels, which havevalves that prevent the backflow of lymph (see figure14.2b).
Lymph nodes filter lymph (see figure 14.4) and aresites where lymphocytes respond to infections.
Lymph enters the thoracic duct or the right lymphaticduct.
Lymph enters the blood.
Lacteals in the small intestine (see figure 16.14)absorb fats, which enter the thoracic duct.
Chyle, which is lymph containing fats, enters theblood.
The spleen (see figure 14.5) filters blood and is a sitewhere lymphocytes respond to infections.
Lymphocytes (pre-B and pre-T cells) originate fromstem cells in the red bone marrow (see figure 14.9).The pre-B cells become mature B cells in the red bonemarrow and are released into the blood. The pre-T cells enter the blood and migrate to the thymus.
The thymus (see figure 14.6) is where pre-T cellsderived from red bone marrow increase in number andbecome mature T cells that are released into the blood(see figure 14.9).
B cells and T cells from the blood enter and populate alllymphatic tissues. These lymphocytes can remain intissues or pass through them and return to the blood.B cells and T cells can also respond to infections bydividing and increasing in number. Some of the newlyformed cells enter the blood and circulate to othertissues.
Blood capillaries
B and T cells
T cellsPre-T cells
B and T cells All lymphatic tissues
Thymus
Red bone marrow B cellsPre-T cells
Spleen (filters blood)
Bone
Thoracic ductLacteals(absorb fats)Small intestine
Lymph node(filters lymph)
Thoracic duct orright lymphatic duct
LymphValves
Fluid
Lymphaticcapillary
Lymphaticvessels
Chyle
Heart
Venous circulationArterial circulation
11
10
10
11
Table 14.1a
Table 11.2-6Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or
display.
Red Blood Cell Transports oxygen and carbon dioxide
White Blood Cells Five types of white blood cells, each withspecific functions
Nucleus with two to four lobes connected by thinfilaments; cytoplasmic granules stain a lightpink or reddish purple; 10–12 μm in diameter
Phagocytizes microorganisms and othersubstances
Nucleus with two indistinct lobes; cytoplasmicgranules stain blue-purple; 10–12 μm in diameter
Nucleus often bilobed; cytoplasmic granules stainorange-red or bright red; 11–14 μm in diameter
Participates in inflammatory response ofallergic reactions and asthma; attacks
certain worm parasites
Lymphocyte
Nucleus round, kidney-shaped, or horseshoe-shaped;contains more cytoplasm than does lymphocyte;
12–20 μm in diameter
Phagocytic cell in the blood; leaves the bloodand becomes a macrophage, which
phagocytizes bacteria, dead cells, cellfragments, and other debris within tissues
TABLE 11.2 Formed Elements of the Blood
Cell Type Illustration Description Function
Granulocytes
Basophil
Eosinophil
Agranulocytes
Monocyte
Spherical cells with a nucleus
Neutrophil
Biconcave disk; no nucleus; contains hemoglobin,which colors the cell red; 6.5–8.5 µm in diameter
Releases histamine, which promotesinflammation, and heparin, which
prevents clot formation
Produces antibodies and other chemicalsresponsible for destroying microorganisms;
contributes to allergic reactions, graftrejection, tumor control, and regulation
of immune system
Round nucleus; cytoplasm forms a thin ringaround the nucleus; 6–14 μm in diameter
Fig. 14.8Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Additional chemicalmediators activated
Tissuerepair
Bacteria gone Bacteria remain
Bacteriaare contained,destroyed, andphagocytized.
Increased numbers ofwhite blood cells andchemical mediators atsite of tissue damage
Chemotaxis,increased vascular permeability,
increased blood flow
Chemical mediatorsare released.
Tissuedamage occurs.
Bacteriaenter tissue.
Fig. 14.9Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Lymphnode
T cell
B cell
Circulation
Thymus
Red bone marrow
Pre-T cell
T cell
Pre-T cell B cell
Pre-B cell
Stem cell
Circulation
Circulation
Fig. 14.12Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Constant regionsof light andheavy chainsSite of binding to
macrophages, basophils,and mast cells
Complement-binding site
Light chain
Heavy chain
Antigen-binding site
Variable regionsof light andheavy chains
Table 14.2
Fig. 14.13 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Inflammation,chemotaxis,lysis
Chemicals
Inflammation
Macrophage
(e) Facilitate phagocytosis. An antibodybinds to an antigen and then to amacrophage, which phagocytizes theantibody and antigen.
(d) Initiate the release of inflammatorychemicals. An antibody binds to a mastcell or a basophil. When an antigen bindsto the antibody, it triggers the release ofchemicals that cause inflammation.
(c) Activate the complement cascade. Anantigen binds to an antibody. As a result,the antibody can activate complementproteins, which can produce inflammation,chemotaxis, and lysis.
(b) Bind antigens together. Antibodies bindseveral antigens together.
(a) Inactivate the antigen. An antibody bindsto an antigen and inactivates it.
Complementcascadeactivated
Antibody
Antigen
Mast cell or basophil
Fig. 14.14 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1
1 2
2
Secondary response. The secondary responseoccurs when another exposure to the same antigencauses the memory cells to rapidly form plasmacells and additional memory cells. The secondaryresponse is faster and produces more antibodiesthan the primary response.
Primary response. The primary response occurswhen a B cell is first activated by an antigen. TheB cell proliferates to form plasma cells andmemory cells. The plasma cells produceantibodies.
Longerresponsetime (3–14 days)
Shorterresponsetime (hours to a few days)
Secondexposure
Secondaryresponse
Moreantibodies
Moreplasmacells
MorememoryB cells
B cell
Fewerantibodies
MemoryB cells
Fewerplasmacells
MemoryB cells
Primaryresponse
FirstexposureM
agn
itu
de
of
resp
on
se
Fig. 14.16
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Target cell lyses.
Cytotoxic T cell
Produce inflammation,initiate phagocytosis, andactivate T cells
Activation of acytotoxic T cellby antigen on thesurface of a cell(see figure 14.15)
T cell
Memory T cells
Target cell
Kill cellson contact
ReleasecytokinesCytotoxic
T cells
Fig. 14.17
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Passive immunity
ArtificialNaturalNatural Artificial
Antibodies produced byanother person or ananimal are injected.
Antibodies from the motherare transferred to her childacross the placenta or in milk.
Antigens aredeliberately introducedin a vaccine.
Antigens are introducedthrough naturalexposure.
Immunity is transferred from anotherperson or an animal.
Active immunity
Immunity is provided by theindividual’s own immune system.
Acquired adaptiveimmunity
Fig. 14.18 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
INNATE IMMUNITY
ADAPTIVE IMMUNITY
Antigen
General response thatdoes not improve withsubsequent exposure
Specific response thatimproves withsubsequent exposure;begins with amacrophage presentingan antigen to a helperT cell
Macrophage
Helper T cell
Physicalbarriers
Neutrophils, macrophages,basophils, and eosinophils
Chemicalmediators
Interferons preventviral infections.
Cytokines and antibodiesenhance inflammationand phagocytosis.
Macrophage presentsprocessed antigen tohelper T cell(see figure 14.10).
Inflammation and phagocytosiscause destruction of the antigen.
Helper T cell proliferates andsecretes cytokines.
Helper T cellHelper T cell
Cytotoxic T cellB cell
Helper T cellcan activate acytotoxic T cell(see figure 14.15).
Helper T cellcan activatea B cell(see figure 14.11).
B cell proliferatesand differentiates.
Cytotoxic T cell proliferatesand differentiates.
Plasma cell Memory B cell Memory T cell Cytotoxic T cell
CytokinesLysis of cellsexpressing antigen
Responsiblefor adaptive immunitysecondary responseDirect effects
against antigen
Antibodies
Antibodies act against antigens in solutionor on the surfaces of extracellularmicroorganisms.
Cytotoxic T cells act against antigens bound to MHCmolecules on the surface of cells; they are effectiveagainst intracellular microorganisms, tumors, andtransplanted cells.
Cell-mediated immunityAntibody-mediated immunity