Lymph sys Flashcards
What are the components of the lymphatic system?
Spleen
Lymph nodes
Lymphatic vessels
Organs of the lymphatic sys
Primary: Bone marrow + Thymus
Secondary: Lymph nodes + spleen
The organ with the largest collection of lymphatic tissues in adults is the
Spleen
Lymphatic Tissues
Specialized form of connective tissue that contains lymphocytes + other immune cells, which help defend the body against pathogens
Thoraic Duct
Drains lymph from the lower body + left upper body into left subclavian vein
Right lymphatic duct
Drains lymph from the right upper body into right subclavian vein
Cisternae chyli
a dilated sac at the base of the thoracic duct that receives lymph from the lower body + intestines
Functions of the Lymphatic sys
Transport excess fluid + protein back to blood stream
Defend body against pathogens
Distribute hormones, nutrients, waste products
Transport dietary fats
Types of lymphocytes
T cells
B cells
Natural Killer (NK) cells
% of lymphocytes in WBCs
20-40%
Organs involved in lymphocyte production + maturation
Produced: Bone marrow
Mature: T cells - Thymus + B cells- Bone marrow
Where lymphocytes can NOT be found
Central Nervous system (CNS)
Classes of lymphocytes + their production sites
T cells: Produced in bone marrow + mature in thymus
B cells: produced + mature in Bone marrow
NK cells: produce in bone marrow
Types of T cells
Helper T cells
Cytotoxic T cells
Suppressor T cells
Helper T cells
Activate B cells + other immune cells
Cytotoxic T cells
Destroy infected or abnormal cells
Suppressor T cells
Regulate + suppress immune responses
T cell activation
Activated by recognizing antigen presented by MHC proteins on antigens presenting cells (macrophages)
Types of B cells
Plasma B cells
Memory B cells
Plasma B cells
Produce antibodies
Memory B cells
Provide long term immunity
B cell activation
Activated by binding to antigens + receiving signals from helper T cells
Lymphoid nodules
Small, localized collections of lymphoid tissues
Filters lymph, remove pathogens, activate immune response
Thymus
Secretes hormone Thymosin, which stimulates T cells maturation
Spleen
Filters blood + removes old + damaged RBCs
Stores blood + Platelets
Initiates immune response by activating B + T cells
Non specific Defense
Repel all microorganism equally
Do NOT target specific pathogens
Types of Non specific defense
Physical barriers
Phagocytes
Immunological surveillance
Interferons
Inflammation
Fever
Physical barriers
Skin
Mucous mem
Phagocytes
Engulf + destroy pathogens
Immunological surveillance
NK cells detect + destroy abnormal cells
Interferons
Proteins that inhibit viral replication
Inflammation
Localized response to injury / infection
Fever
Increase in body temp to inhibit pathogen growth
Specific defense
Targets specific pathogens + involves activation of lymphocytes (B + T Cells )
Characteristics: Specific, Memory, Versatility, Tolerance
Cell responsible for cell mediated immunity
T cells
Cells responsible for antibody mediated immunity
B cells
Types of immunity
Innate immunity
Acquired immunity
Innate immunity
In you
Genetically determined immunity
Acquired immunity
Acquired through antibodies from another source (mother milk or injection)
MHC class proteins
MHC class I
MHC class II
MHC class I
Found on ALL nucleated cells
Present intracellular antigens to cytotoxic T cells
MHC class II
Found on antigens presenting cells (macrophages)
Present extracellular antigens to helper T cells
Antibodies
Proteins produced by B cells that recognize + bind to specific antigens
Produced by Plasma B cells
Neutralize pathogens, activate complement, mark pathogens for destruction
IgG antibody
Most abundant
Long term Immunity
Classes of antibodies
IgG
IgM
IgA
IgE
IgD
IgM antibody
First antibody produced during infection
IgA antibody
Found in secretion (saliva, breast milk)
IgE antibody
Involved in allergic reactions
IgD antibody
Found on B cell surfaces, involved in B cells activation
