Upload
augustine-russell
View
224
Download
0
Tags:
Embed Size (px)
Citation preview
Chapter 13Chapter 13The Lymphatic System and The Lymphatic System and
ImmunityImmunity
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 2
THE LYMPHATIC SYSTEM (FIGURE 13-1)THE LYMPHATIC SYSTEM (FIGURE 13-1)
Lymph—fluid in the tissue spaces that carries protein molecules Lymph—fluid in the tissue spaces that carries protein molecules and other substances back to the bloodand other substances back to the blood
Lymphatic vessels—permit only one-way movement of lymphLymphatic vessels—permit only one-way movement of lymph Lymphatic capillaries—tiny blind-ended tubes distributed in tissue Lymphatic capillaries—tiny blind-ended tubes distributed in tissue
spaces (Figure 13-2)spaces (Figure 13-2)• Microscopic in sizeMicroscopic in size• Sheets consisting of one cell layer of simple squamous epitheliumSheets consisting of one cell layer of simple squamous epithelium• Poor “fit” between adjacent cells results in porous wallsPoor “fit” between adjacent cells results in porous walls• Called Called lactealslacteals in the intestinal wall (fat transportation from food to in the intestinal wall (fat transportation from food to
bloodstream)bloodstream) Right lymphatic duct (Figure 13-3)Right lymphatic duct (Figure 13-3)
• Drains lymph from the right upper extremity and right side of head, neck, Drains lymph from the right upper extremity and right side of head, neck, and upper torsoand upper torso
Thoracic ductThoracic duct• Largest lymphatic vesselLargest lymphatic vessel• Has an enlarged pouch along its course, called Has an enlarged pouch along its course, called cisterna chylicisterna chyli• Drains lymph from about three-fourths of the body (Figure 13-3)Drains lymph from about three-fourths of the body (Figure 13-3)
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 3
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 4
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 5
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 6
THE LYMPHATIC SYSTEMTHE LYMPHATIC SYSTEM
Lymph nodesLymph nodes Filter lymph (Figure 13-4)Filter lymph (Figure 13-4) Located in clusters along the pathway of Located in clusters along the pathway of
lymphatic vessels (Figures 13-1, 13-5, and 13-lymphatic vessels (Figures 13-1, 13-5, and 13-6)6)
Functions include defense and WBC formationFunctions include defense and WBC formation Flow of lymph: to node via several afferent Flow of lymph: to node via several afferent
lymph vessels and drained from node by a lymph vessels and drained from node by a single efferent lymph vesselsingle efferent lymph vessel
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 7
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 8
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 9
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 10
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 11
THE LYMPHATIC SYSTEMTHE LYMPHATIC SYSTEM
ThymusThymus Lymphoid tissue organ located in mediastinumLymphoid tissue organ located in mediastinum Total weight of 35 to 40 g—a little more than Total weight of 35 to 40 g—a little more than
an ouncean ounce Plays a vital and central role in immunityPlays a vital and central role in immunity Produces T-lymphocytes, or T cellsProduces T-lymphocytes, or T cells Secretes hormones called Secretes hormones called thymosinsthymosins Lymphoid tissue is largely replaced by fat in Lymphoid tissue is largely replaced by fat in
the process called the process called involutioninvolution
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 12
THE LYMPHATIC SYSTEMTHE LYMPHATIC SYSTEM
Tonsils (Figure 13-7)Tonsils (Figure 13-7) Composed of three masses of lymphoid tissue Composed of three masses of lymphoid tissue
around the openings of the mouth and throataround the openings of the mouth and throat• Palatine tonsils (“the tonsils”)Palatine tonsils (“the tonsils”)• Pharyngeal tonsils (also known as Pharyngeal tonsils (also known as adenoidsadenoids))• Lingual tonsilsLingual tonsils
Subject to chronic infectionSubject to chronic infection Enlargement of pharyngeal tonsils may impair Enlargement of pharyngeal tonsils may impair
breathingbreathing
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 13
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 14
THE LYMPHATIC SYSTEMTHE LYMPHATIC SYSTEM
SpleenSpleen Largest lymphoid organ in bodyLargest lymphoid organ in body Located in upper left quadrant of abdomenLocated in upper left quadrant of abdomen Often injured by trauma to abdomenOften injured by trauma to abdomen Surgical removal called Surgical removal called splenectomysplenectomy Functions include phagocytosis of bacteria and Functions include phagocytosis of bacteria and
old RBCs; acts as a blood reservoirold RBCs; acts as a blood reservoir
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 15
THE IMMUNE SYSTEM THE IMMUNE SYSTEM (TABLE 13-1)(TABLE 13-1)
Protects body from pathological bacteria, foreign Protects body from pathological bacteria, foreign tissue cells, and cancerous cellstissue cells, and cancerous cells
Made up of specialized cells and moleculesMade up of specialized cells and molecules Nonspecific immunityNonspecific immunity
Also called Also called innate immunityinnate immunity because it does not require because it does not require prior exposure to an antigenprior exposure to an antigen
Skin—mechanical barrier to bacteria and other harmful Skin—mechanical barrier to bacteria and other harmful agentsagents
Tears and mucus—wash eyes and trap and kill bacteriaTears and mucus—wash eyes and trap and kill bacteria Inflammation—attracts immune cells to site of injury, Inflammation—attracts immune cells to site of injury,
increases local blood flow, increases vascular increases local blood flow, increases vascular permeability; promotes movement of WBCs to site of permeability; promotes movement of WBCs to site of injury or infection (Figure 13-8)injury or infection (Figure 13-8)
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 16
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 17
THE IMMUNE SYSTEMTHE IMMUNE SYSTEM
Specific immunitySpecific immunity Also called Also called adaptive immunityadaptive immunity because of the ability of because of the ability of
the body to recognize, respond to, and remember the body to recognize, respond to, and remember harmful substances or bacteriaharmful substances or bacteria
Types of specific immunityTypes of specific immunity• Natural immunity—exposure to causative agent is not Natural immunity—exposure to causative agent is not
deliberatedeliberate Active—active disease produces immunityActive—active disease produces immunity Passive—immunity passes from mother to fetus through Passive—immunity passes from mother to fetus through
placenta or from mother to child through mother’s milkplacenta or from mother to child through mother’s milk• Artificial immunity—exposure to causative agent is Artificial immunity—exposure to causative agent is
deliberatedeliberate Active—vaccination results in immunityActive—vaccination results in immunity Passive—protective material developed in another Passive—protective material developed in another
individual’s immune system and given to previously individual’s immune system and given to previously nonimmune individualnonimmune individual
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 18
IMMUNE SYSTEM MOLECULESIMMUNE SYSTEM MOLECULES
AntibodiesAntibodies Protein compounds with specific combining sitesProtein compounds with specific combining sites Combining sites attach antibodies to specific antigens Combining sites attach antibodies to specific antigens
(foreign proteins), forming an antigen-antibody complex(foreign proteins), forming an antigen-antibody complex—called —called humoral,humoral, or or antibody-mediated, immunityantibody-mediated, immunity (Figure 13-9)(Figure 13-9)
Antigen-antibody complexes may:Antigen-antibody complexes may:• Neutralize toxinsNeutralize toxins
• Clump or agglutinate enemy cellsClump or agglutinate enemy cells
• Promote phagocytosisPromote phagocytosis
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 19
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 20
IMMUNE SYSTEM MOLECULESIMMUNE SYSTEM MOLECULES
Complement proteinsComplement proteins Group of proteins normally present in blood in inactive Group of proteins normally present in blood in inactive
statestate Complement cascadeComplement cascade
• Important mechanism of action for antibodiesImportant mechanism of action for antibodies
• Causes cell lysis by permitting entry of water through a Causes cell lysis by permitting entry of water through a defect created in the plasma membrane (Figure 13-10)defect created in the plasma membrane (Figure 13-10)
Also perform other functions (Also perform other functions (examples:examples: attracting attracting immune cells to a site of infection, activating immune immune cells to a site of infection, activating immune cells, marking foreign cells for destruction, increasing cells, marking foreign cells for destruction, increasing permeability of blood vessels)permeability of blood vessels)
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 21
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 22
IMMUNE SYSTEM CELLSIMMUNE SYSTEM CELLS
Phagocytes—ingest and destroy foreign Phagocytes—ingest and destroy foreign cells or other harmful substances via cells or other harmful substances via phagocytosis (Figure 13-11)phagocytosis (Figure 13-11) TypesTypes
• NeutrophilsNeutrophils
• MonocytesMonocytes
• MacrophagesMacrophages Kupffer cells (liver)Kupffer cells (liver) Dust cells (lung)Dust cells (lung)
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 23
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 24
IMMUNE SYSTEM CELLSIMMUNE SYSTEM CELLS
LymphocytesLymphocytes Most numerous of immune system cellsMost numerous of immune system cells Development of B cells—primitive stem cells migrate from Development of B cells—primitive stem cells migrate from
bone marrow and go through two stages of development bone marrow and go through two stages of development (Figure 13-12)(Figure 13-12)
• First stage—stem cells develop into immature B cells; takes place First stage—stem cells develop into immature B cells; takes place in the liver and bone marrow before birth and in the bone marrow in the liver and bone marrow before birth and in the bone marrow only in adults; immature B cells are small lymphocytes with only in adults; immature B cells are small lymphocytes with antibody molecules (which they have synthesized) in their plasma antibody molecules (which they have synthesized) in their plasma membranes; migrate chiefly to lymph nodesmembranes; migrate chiefly to lymph nodes
• Second stage—immature B cell develops into activated B cell; Second stage—immature B cell develops into activated B cell; initiated by immature B cell’s contact with antigens, which bind to initiated by immature B cell’s contact with antigens, which bind to its surface antibodies; activated B cell, by dividing repeatedly, its surface antibodies; activated B cell, by dividing repeatedly, forms two clones of cells—plasma cells and memory cells—forms two clones of cells—plasma cells and memory cells—plasma cells secrete antibodies into blood; memory cells stored in plasma cells secrete antibodies into blood; memory cells stored in lymph nodes; if subsequent exposure to antigen that activated B lymph nodes; if subsequent exposure to antigen that activated B cell occurs, memory cells become plasma cells and secrete cell occurs, memory cells become plasma cells and secrete antibodiesantibodies
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 25
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 26
IMMUNE SYSTEM CELLSIMMUNE SYSTEM CELLS
Lymphocytes (cont.)Lymphocytes (cont.) Function of B cells—indirectly, B cells produce humoral Function of B cells—indirectly, B cells produce humoral
immunity; activated B cells develop into plasma cells; plasma immunity; activated B cells develop into plasma cells; plasma cells secrete antibodies into the blood; circulating antibodies cells secrete antibodies into the blood; circulating antibodies produce humoral immunity (Figure 13-12)produce humoral immunity (Figure 13-12)
Development of T cells—stem cells from bone marrow migrate Development of T cells—stem cells from bone marrow migrate to thymus gland (Figure 13-13)to thymus gland (Figure 13-13)
• Stage 1—stem cells develop into T cells; occurs in thymus during Stage 1—stem cells develop into T cells; occurs in thymus during few months before and after birth; T cells migrate chiefly to lymph few months before and after birth; T cells migrate chiefly to lymph nodesnodes
• Stage 2—T cells develop into sensitized T cells; occurs when, and Stage 2—T cells develop into sensitized T cells; occurs when, and if, antigen binds to T cell’s surface proteinsif, antigen binds to T cell’s surface proteins
Functions of T cells—produce cell-mediated immunity; kill Functions of T cells—produce cell-mediated immunity; kill invading cells by releasing a substance that poisons cells and invading cells by releasing a substance that poisons cells and also by releasing chemicals that attract and activate also by releasing chemicals that attract and activate macrophages to kill cells by phagocytosis (Figures 13-14 and macrophages to kill cells by phagocytosis (Figures 13-14 and 13-15)13-15)
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 27
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 28
Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 29