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Announcements

Exams-
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Extra Credit -
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Lab 5 - Lymphatic System
Lecture Overview

Lymphatic System and Components
– What is lymph and how does it travel?
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General Immune Reaction- Inflammation
– What is one function of the cells carried in
lymph?
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Selected Topics in Immunity
Lymphatic System
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Absorbs excess fluid from the tissues
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Returns this fluid to the circulatory system
or the heart
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Additional function in Immunity
Components of the Lymphatic
System
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Lymph
 Lymphatic Tissue
 Lymphatic Vessels
 Thymus
 Bone Marrow
 Spleen
Lymph
 Lymph
– The clear fluid
absorbed by
the lymphatic
system
 Lymphatic Tissue
– Clusters of
Lymphocytes
and
macrophages
Lymphatic Tissue
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Malt: (Mucosa Associated Lymphatic Tissue)
– Diffuse array of lymphocytes found along body
passages in mucous membranes.
– Examples of malt: lining of the stomach and
respiratory tract
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Lymph nodules:
– Dense clusters of Lymphocytes
– Transient: pop up during infection
Lymphatic Vessels
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Carry and Transport
Lymph and proteins
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Similar Structure to
veins
– Tunica Interna:
Thin inner lining
and valves
– Tunica Media:
Elastic fibers and
Smooth Muscle
– Tunica Externa:
Thin Outer Layer
Lymphatic Filters
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Lymph Nodes- Screen and Filter
Lymph for infectious particles
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Spleen- Screen and Filter Blood for
old, dead cells and infectious particles
Subclavian
2 collecting Trunks
6 Lymphatic Trunks
More Collecting Vessels
Lymph Nodes
Collecting Vessels
Lymphatic Vessels
Lymphatic Movement
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No pump
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Rhythmic contraction of the lymph vessels
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Skeletal Muscles
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How is backflow prevented?
Immune Cell Generators
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Bone Marrow- Makes B- Cells
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Thymus- Makes T- Cells
Thymus
Break for
Dynamic Human
Inflammation
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Non-specific response to tissue trauma or
infection
4 signs of Inflammation
4 signs of Inflammation
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Redness
 Swelling
 Heat
 Pain
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What’s the purpose of pain?
Purpose of Inflammation
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Remove Invading Pathogens
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Remove Debris of Damaged Tissues
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Initiate Tissue Repair
Mediators of Inflammation
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Chemical Messengers
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Leukocyte
Chemical Messengers
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Released by mast cells in response to damage
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Bradykinin, Histamine, and Leukotrienes
– Increases Local Blood Flow to distressed area
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Stimulates Vasodilation
Increases Permeability of Capillaries
What’s Accomplished?
Chemical Messengers
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Bradykinin, Histamine, and Leukotrienes
– Increases Local Blood Flow
 Stimulates Vasodilation
 Increases Permeability of Capillaries
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What’s Accomplished?
– Heats area causes redness and swelling
– Dilutes toxins and helps Remove waste
– Supplies oxygen and nutrients for tissue repair
Pain Response
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Purpose?
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Causes?
Pain Response
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Purpose? Prevents further injury to area.
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Causes?
– Direct Nerve Damage
– Pressure from Swelling
– Chemical Stimulation particularly bradykinin
Leukocyte Deployment
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Leukocyte: any white blood cell including
T cells, B cells, granulocytes, platelets,
basophils, mast cells, monocytes and
macrophages
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Leukocytes Migrate toward inflammed area
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Why? TO KILL and RECRUIT
Leukocyte Deployment
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Leukocytes Migrate to inflammed tissue
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How?
1. Margination or pavementing: To
migrate to the wall of a capillary
2. Diapedesis: Passage of blood cells
through vessel wall into tissue
3. Chemotaxis: Movement of a cell
towards or away a chemical source
What do the leukocytes plan
to do?
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Phagocytosis: release of toxic chemicals
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Recruit more leukocytes
Phagocytosis
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Leukocytes consume and destroy foreign
invaders and dead cells
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Ejected as Pus
Break for
Dynamic Human
Selected Topics in Immunity