Structure/Organization of Lymph Flashcards
What kind of tissue is Lymphatic tissue?
Reticular connective tissue
Body system responsible for adaptive (and in some aspects innate) immunity?
Lymphatic system
What makes interstitial fluid and lymph different from blood plasma?
Less protein due to it being too large to filter through capillary wall
How many liters of fluid filter from blood into tissue spaces?
About 20 liters
Which system must fluid flow back to in order to maintain normal blood volume?
Cardiovascular system
How many liters of fluid is filtered daily from the arterial end of blood capillaries?
About 17 liters
How many liters per day pass into the lymphatic vessels and returned to the blood?
About 3 liters
What are the 3 primary functions of the lymphatic system?
- Drains excess interstitial fluid
- Transports dietary lipids
- Carries out immune response
How are endothelial cells that make up the wall of a lymphatic capillary connected?
Overlap at the ends rather than being attached end to end
What happens when pressure is greater in interstitial fluid than in lymph?
The cells separate like a one way swinging door
What happens when pressure is greater inside the lymphatic capillary?
The cells adhere more closely and the lymph cannot escape back into interstitial fluid
Lymphatic capillaries unite to form what?
Larger lymphatic vessels
Where do lymphatic vessels begin and where does it carry lymph?
Begins in the tissues and carries lymph towards larger lymphatic vessels
What is the difference between lymphatic vessels and veins?
Lymphatic vessels have thinner walls and more valves
What are the 2 main lymphatic channels?
- Thoracic duct
- Right lymphatic duct
Which is the main lymph collecting duct?
Thoracic duct
Where does the thoracic duct receive lymph from?
Left side of head, neck, chest, left upper limbs and entire body below the ribs
Where does the right lymphatic duct receive lymph?
Upper right side of body
Where does the thoracic duct empty lymph?
Left internal jugular and left subclavian veins
Where does the right lymphatic duct empty lymph?
Right internal jugular and right subclavian veins
Which 2 pumps aid the return of venous blood to the heart and maintain the flow of lymph?
- Skeletal muscle pump
- Respiratory pump
What action of the skeletal muscle contractions compresses lymphatic vessels and forces lymph into the subclavian veins?
Milking action
What prevents the backflow of lymph upon exhalation?
Valves
What are the primary lymphatic organ?
- Red bone marrow
- Thymus
What are the secondary lymphatic organs?
- Lymph nodes
- Spleen
- Lymphatic Nodules
Where are lymph nodes heavily concentrated?
Mammary glands, axillae and groin
Lymph nodes contain what cells?
B cells, plasma cells, T cells, dendritic cells and macrophages
What is the largest single mass of lymphatic tissue in the body?
Spleen
The spleen has what 2 types of tissue?
White pulp
Red Pulp
What is the white pulp in the spleen?
Lymphatic tissue where B and T cells carry out immune response
What is the red pulp in the spleen?
Blood filled sinuses where worn-out blood cells and platelets are removed
What is innate immunity?
Barriers provide by the skin and mucous membranes (first line of defense) and various internal defense (second line of defense) such as antimicrobial substances, natural killer cells, phagocytes, inflammation and fever
What are the 2 types of adaptive immunity?
Cell-mediated immunity and antibody-medicated immunity
What are phagocytes?
Cells that perform phagocytosis thus the ingestion of microbes or other particles
What are natural killer cells?
About 5-10% of lymphocytes that can kill a wide variety of microbes and tumor cells
What is inflammation and how does it help?
Non specific response of body to tissue damage
Prevents spread to other tissues and prepares site for repair
How does fever help the body?
Intensifies effects of interferons, inhibits microbial growth and speeds up reactions that aid in repair
Where are natural killer cells present?
Spleen, nodes and bone marrow
What are the 4 main types of antimicrobial substances in the second line of defense?
- Interferons (IFNs)
- Complement System
- Iron- binding proteins
- Antimicrobial Proteins (AMPs)
Lymphocytes, macrophages and fibroblasts infected with viruses produce proteins called?
Interferons (IFNs)
A group of normally inactive proteins in blood plasma and on plasma membranes make up what system?
Complement system
What does the complement system enhance?
Immune, allergic and inflammatory reaction
Complement system proteins do what to plasma membranes in microbes?
Creates holes
Which proteins inhibit the growth of certain bacteria by reducing the amount of available iron?
Iron-binding protein
What are short peptides that have a broad spectrum of antimicrobial activity?
Antimicrobial Proteins
What are examples of antimicrobial proteins?
- Dermicidin (produced by sweat glands)
- Cathelicidins (produced by neutrophils, macrophages and epithelia)
- Thrombocidin (produced by platelets)
Besides killing a wide range of microbes, what else do AMPs attract to participate in immune response?
Dendritic cells and mast cells
What is the next nonspecific defense when microbes penetrate the skin and mucous membranes or by pass antimicrobial substances in blood?
Phagocytes and Natural Killer cells
What are the 4 signs of inflammation?
Redness, pain, heat and swelling
Inflammation can cause what to happen to the function of an injured area?
Loss of function depending on the site and extent of injury
What is an antigen?
Any substance such as microbes, foods, drugs, pollen or tissue that the immune system recognizes as foreign
What branch of science deals with responses of the body to antigens?
Immunology
What are the 2 major types of mature T Cells that exit the thymus?
Helper T Cells and Cytotoxic T Cells
What are the 2 types of adaptive immunity?
Cell mediated and antibody-mediated immunity
Cell mediated immunity is particularly effective against what?
- Intracellular pathogens
- Cancer cells
- Foreign tissue implants
What immunity involves antibodies that bind to antigens in body humors or fluids (such as blood and lymph)?
Antibody- mediated immunity
What is another name for anti-body mediated immunity?
Humoral immunity
When lymphocytes encounter a copy of the antigen and receives stimulatory cues, what does it undergo?
Clonal selection
What is clonal selection?
Formation of a population of identical cells that can recognize the same specific antigen as the original lymphocyte
What is the difference in lymphocytes from first exposure to antigen to after clonal selection occurs?
First exposure, only a few lymphocytes are able to recognize antigen
After clonal selection, thousands of lymphocytes respond
Where does clonal selection occur?
Secondary lymphatic tissues
A lymphocyte that undergoes clonal selections gives rise to what 2 major types of cells?
Effector cells and memory cells
Effector cells include what cells?
Active helper T cells, Active cytotoxic T cells and plasma cells
When do effector cells die off?
After immune response has been completed
What part of the immune response do memory cells participate in?
Memory cells do not actively participate in the initial immune response
How long do memory cells last?
Long life span, often lasting decades
Examples of antigens?
Pollen, egg, incompatible blood cells, transplanted tissues
What are the “self-antigens” located at the plasma membrane surface of most body cells?
Major histocompatibility complex (MHC) protiens
Antibodies bind to particular antigen much like?
Key fits into lock
What shape can antibodies assume?
T or Y shape
What are the 5 classes of immunoglobulins?
IgM, IgA, IgD, IgE, IgG
Which immunoglobulin is short lived and indicates a recent invasion?
IgM
Which immunoglobulin can cross the placenta?
IgG
Which immunoglobulin is in breast milk?
IgA
