The Lymphatic SystemThe Lymphatic System

Slide 12.1Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Consists of ________ parts

Lymphatic vessels

Lymphoid tissues and organs

Lymphatic system functions

_______________ fluids back to the blood

Play essential roles in body _________________ and resistance to disease

Lymphatic CharacteristicsLymphatic Characteristics

Slide 12.2Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

__________________– excess tissue fluid carried by lymphatic vessels

lymphatic vessels are… One way system toward the heart

No pump involved so the lymph is moved via:

Milking action of skeletal muscle

Rhythmic contraction of smooth muscle in vessel walls

Lymphatic VesselsLymphatic Vessels

Slide 12.3aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Lymph ______________________

Walls overlap to form flap-like minivalves

Fluid leaks into lymph capillaries

Capillaries are anchored to connective tissue by filaments

Higher pressure on the inside closes minivalves

Lymphatic VesselsLymphatic Vessels

Slide 12.3bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 12.1

See Page 369

Lymphatic VesselsLymphatic Vessels

Slide 12.4aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Lymphatic ____________ vessels

Collects lymph from lymph capillaries

Carries lymph to and away from lymph nodes

Figure 12.2

See Page 370

Lymphatic VesselsLymphatic Vessels

Slide 12.4bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Lymphatic collecting vessels (continued)

Returns fluid to circulatory veins near the heart

Right lymphatic duct

Thoracic ductFigure 12.2

See Page 370

LymphLymph

Slide 12.5aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Materials returned to the blood

Harmful materials that enter lymph vessels

Lymph NodesLymph Nodes

Slide 12.6aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

______________________ lymph before it is returned to the blood

Defense cells within lymph nodes

______________________– engulf and destroy foreign substances

______________________– provide immune response to antigens

Lymph NodesLymph Nodes

Slide 12.6bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 12.3

See Page 371

Lymph Node StructureLymph Node Structure

Slide 12.7aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Most are kidney-shaped, less than 1 inch long

______________________

Outer part

Contains follicles – collections of lymphocytes

______________________

Inner part

Contains phagocytic macrophages

Lymph Node StructureLymph Node Structure

Slide 12.7bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 12.4

See Page 371

Flow of Lymph Through NodesFlow of Lymph Through Nodes

Slide 12.8Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Lymph enters the ______________________ side through afferent lymphatic vessels

Lymph flows through a number of sinuses inside the ______________________

Lymph exits through ______________________

lymphatic vessels

Fewer efferent than afferent vessels causes flow to be slowed

Other Lymphoid OrgansOther Lymphoid Organs

Slide 12.9Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Several other organs contribute to lymphatic function

Figure 12.5

See Page 372

The SpleenThe Spleen

Slide 12.10Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Located on the ___________side of the abdomen

Filters blood

Destroys worn out blood cells

Forms blood cells in the fetus

Acts as a blood reservoir

The ThymusThe Thymus

Slide 12.11Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Located low in the throat, overlying the heart

Functions at peak levels only during childhood

Produces ______________________(like thymosin) to program lymphocytes

TonsilsTonsils

Slide 12.12Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Small masses of lymphoid tissue around the pharynx

Trap and remove ______________________ and other foreign materials

______________________ is caused by congestion with bacteria

Peyer’s PatchesPeyer’s Patches

Slide 12.13Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Found in the wall of the ____________________

Resemble tonsils in structure

Capture and destroy bacteria in the intestine

Mucosa-Associated Lymphatic Mucosa-Associated Lymphatic Tissue (MALT)Tissue (MALT)

Slide 12.14Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Includes:

Peyer’s patches

Tonsils

Other small accumulations of lymphoid tissue

Acts as a sentinal to protect respiratory and digestive tracts

Body DefensesBody Defenses

Slide 12.15aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The body is constantly in contact with bacteria, fungi, and viruses

The body has two defense systems for foreign materials

______________________ defense system

Mechanisms protect against a variety of invaders

Responds immediately to protect body from foreign materials

Body DefensesBody Defenses

Slide 12.15bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

______________________ defense system

Specific defense is required for each type of invader

Also known as the immune system

Nonspecific Body DefensesNonspecific Body Defenses

Slide 12.16Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Body surface coverings

Specialized human cells

Chemicals produced by the body

Surface Membrane Barriers – Surface Membrane Barriers – First Line of DefenseFirst Line of Defense

Slide 12.17aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The skin

Physical barrier to foreign materials

pH of the skin is acidic to inhibit bacterial growth

Sebum is toxic to bacteria

Vaginal secretions are very acidic

Surface Membrane Barriers – Surface Membrane Barriers – First Line of DefenseFirst Line of Defense

Slide 12.17bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Stomach mucosa

Secretes ______________________

Has protein-digesting enzymes

Saliva and lacrimal fluid contain ______________________

Mucus traps microorganisms in digestive and respiratory pathways

Defensive CellsDefensive Cells

Slide 12.18aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

______________________

(neutrophils and macrophages)

Engulfs foreign material into a vacuole

Enzymes from lysosomes digest the material

Figure 12.6b

See Page 374

Defensive CellsDefensive Cells

Slide 12.18bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Natural killer cells

Can lyse and kill cancer cells

Can destroy virus- infected cells

Figure 12.6b

See Page 374

Inflammatory Response - Inflammatory Response - Second Line of DefenseSecond Line of Defense

Slide 12.19Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Triggered when body tissues are injured

Produces four cardinal signs

Results in a chain of events leading to protection and healing

Functions of the Inflammatory Functions of the Inflammatory ResponseResponse

Slide 12.20Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Prevents spread of damaging agents

Disposes of cell debris and pathogens

Sets the stage for repair

Steps in the Inflammatory ResponseSteps in the Inflammatory Response

Slide 12.21Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 12.7

See Page 375

Antimicrobial ChemicalsAntimicrobial Chemicals

Slide 12.22aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Complement A group of at

least 20 plasma proteins

Activated when they encounter and attach to cells (complement fixation) Figure 12.8

See Page 377

Antimicrobial ChemicalsAntimicrobial Chemicals

Slide 12.22bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Complement (continued)

Damage foreign cell surfaces

Has vasodilators, chemotaxis, and opsonization

Figure 12.8

See Page 377

Antimicrobial ChemicalsAntimicrobial Chemicals

Slide 12.22cCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

____________

Secreted proteins of virus-infected cells

Bind to healthy cell surfaces to inhibit viruses binding