Fig. 14.1-1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) Tonsils Cervical lymph node Inguinal lymph

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


(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


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


(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

9

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


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.


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


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


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


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


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


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


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

Documents

Fig. 14.1-1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) Tonsils Cervical lymph node Inguinal lymph