Essentials of Anatomy and Physiology Fifth edition Seeley, Stephens and Tate Slide 2.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chapter 14: Lymphatic System and Immunity

The Lymphatic System Slide 12.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Consists of two components  Lymphatic vessels  Lymphoid tissues and organs  Functions  Transport fluids back to the blood  Body’s defense against disease

Lymphatic Characteristics Slide 12.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lymph  Tissue fluid in lymphatic vessels  Body produces ~3L/day (how much blood do we have???)  Properties of lymphatic vessels  One way system toward the heart  No pump  Assisted by skeletal muscle

Lymphatic Vessels Slide 12.3a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lymph Capillaries  “Blind tubes”  Walls have valves  Fluid leaks into lymph capillaries  Higher pressure inside closes valves

Lymphatic Vessels Slide 12.3b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.1

Lymphatic Vessels Slide 12.4a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lymphatic vessels  Collect lymph from lymph capillaries  Carry lymph to nodes Figure 12.2

Lymphatic Vessels Slide 12.4b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lymphatic vessels (continued)  Returns fluid to subclavian veins  Right lymphatic duct  Thoracic duct Figure 12.2

Lymph Slide 12.5a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Materials returned to the blood  Water  Blood cells  Proteins

Lymph Slide 12.5b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Harmful materials that enter lymph vessels  Bacteria  Viruses  Cancer cells  Cell debris

Lymph Nodes Slide 12.6a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Filter lymph before it is returned to the blood  Nodes house immune WBCs  Macrophages  Lymphocytes

Lymph Nodes Slide 12.6b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.3

Lymph Node Structure Slide 12.7a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Bean shaped, less than 1” long  Cortex  Contains collections of lymphocytes  Medulla  Contains macrophages

Lymph Node Structure Slide 12.7b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.4

Other Lymphoid Organs Slide 12.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Spleen  Thymus  Tonsils  Peyer’s patches Figure 12.5

The Spleen Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Located on the left side of the abdomen  Filters blood  Destroys worn out blood cells  Forms blood cells in the fetus  Acts as a blood reservoir

The Thymus Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Located deep to sternum  Functions mostly during childhood  Produces hormones  Thymosin, thymopoietin  Program T-lymphocytes

Lymphoid Organs Thymus: atrophies with age Spleen: can live without this Figure 20.8

Tonsils Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Masses of lymphoid tissue surrounding pharynx  Trap and remove bacteria and other foreign materials  Tonsillitis: caused by infection with bacteria

Peyer’s Patches Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Found in the wall of the small intestine  Collections of lymphocytes  Capture and destroy bacteria in the intestine

Lymphoid Organs Tonsils: 3 sets Peyer’s patches: part of GALT Figure 20.8

Body Defenses Slide 12.15a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The body is constantly assaulted by micro-organisms  We have two forms of defense  Nonspecific or Innate defenses  Protect against a variety of invaders  Responds immediately  Includes granulocytes and monocytes

Body Defenses, con’t… Slide 12.15b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Specific or Acquired defense system: Cell Mediated response  Specific defense is required for each type of invader  T-cells: viruses, fungi, cancer cells Cell mediated response

Acquired Defenses, con’t… Slide 12.15b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Humoral Immunity  T-cells influence B-cells  B-cells: Bacteria  B-cells make antibodies (Ab)  Ab circulate in blood Humoral Immunity: Ab production

Nonspecific Body Defenses Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Body surface coverings  Intact skin  Mucous membranes  Specialized WBCs  Chemicals produced by the body

Defensive Cells Slide 12.18a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Phagocytes  Neutrophils  Monocyte/ Macrophages Figure 12.6b

Defensive Cells Slide 12.18b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Natural killer cells  A lymphocyte  Can kill cancer cells  Can destroy virus- infected cells  How: surface Ag change Figure 12.6b

Inflammatory Response is the Second Line of Defense: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Triggered by injury  Produces four signs  Redness  Heat  Swelling  Pain

Functions of the Inflammatory Response: FYI Slide Copyright © 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 Response: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.7

Antimicrobial Chemicals: FYI Slide 12.22c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Complement  Protein cascade  Kills invaders  Interferon  Proteins secreted by virus-infected cells  Inhibit virus binding to healthy cells

Fever: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Abnormally high body temperature  Inhibits the release of substances needed by bacteria  Increases the speed of tissue repair