Transcript Document
Announcements
Exams-
Extra Credit -
Lab 5 - Lymphatic System
Lecture Overview
Lymphatic System and Components
– What is lymph and how does it travel?
General Immune Reaction- Inflammation
– What is one function of the cells carried in
lymph?
Selected Topics in Immunity
Lymphatic System
Absorbs excess fluid from the tissues
Returns this fluid to the circulatory system
or the heart
Additional function in Immunity
Components of the Lymphatic
System
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
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
Lymph nodules:
– Dense clusters of Lymphocytes
– Transient: pop up during infection
Lymphatic Vessels
Carry and Transport
Lymph and proteins
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
Lymph Nodes- Screen and Filter
Lymph for infectious particles
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
No pump
Rhythmic contraction of the lymph vessels
Skeletal Muscles
How is backflow prevented?
Immune Cell Generators
Bone Marrow- Makes B- Cells
Thymus- Makes T- Cells
Thymus
Break for
Dynamic Human
Inflammation
Non-specific response to tissue trauma or
infection
4 signs of Inflammation
4 signs of Inflammation
Redness
Swelling
Heat
Pain
What’s the purpose of pain?
Purpose of Inflammation
Remove Invading Pathogens
Remove Debris of Damaged Tissues
Initiate Tissue Repair
Mediators of Inflammation
Chemical Messengers
Leukocyte
Chemical Messengers
Released by mast cells in response to damage
Bradykinin, Histamine, and Leukotrienes
– Increases Local Blood Flow to distressed area
Stimulates Vasodilation
Increases Permeability of Capillaries
What’s Accomplished?
Chemical Messengers
Bradykinin, Histamine, and Leukotrienes
– Increases Local Blood Flow
Stimulates Vasodilation
Increases Permeability of Capillaries
What’s Accomplished?
– Heats area causes redness and swelling
– Dilutes toxins and helps Remove waste
– Supplies oxygen and nutrients for tissue repair
Pain Response
Purpose?
Causes?
Pain Response
Purpose? Prevents further injury to area.
Causes?
– Direct Nerve Damage
– Pressure from Swelling
– Chemical Stimulation particularly bradykinin
Leukocyte Deployment
Leukocyte: any white blood cell including
T cells, B cells, granulocytes, platelets,
basophils, mast cells, monocytes and
macrophages
Leukocytes Migrate toward inflammed area
Why? TO KILL and RECRUIT
Leukocyte Deployment
Leukocytes Migrate to inflammed tissue
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?
Phagocytosis: release of toxic chemicals
Recruit more leukocytes
Phagocytosis
Leukocytes consume and destroy foreign
invaders and dead cells
Ejected as Pus
Break for
Dynamic Human
Selected Topics in Immunity