Lymphatic System Flashcards
Functions of the lymphatic system
Defending his infection disease. Return tissue fluid to the bloodstream
What do you call the fluid that is transported by the lymphatic vessels
Lymph
Pathogens
Disease causing organisms include bacteria viruses fungi and parasites
Lymphatic system
The cells tissues and organs that defend the body. Primary cells of the system are lymphocytes
Nonspecific defences
Anatomical barriers
Prevent or slow entry of infectious stuff
Born with them
Don’t distinguish one threat from another
Specific defended
Immune response
Lymphocytes respond to specific threats
Adaptive bc the immune response will adapt and change depending on the type of pathogen
The immune system
The cells and tissues involved in the production of immunity
Includes: digestive, integumentary, lymphatic, cardiovascular, respiratory
Lymphatic vessels
Carry fluid froM peripheral tissues to veins
The fluid that flows through lymphatic vessels. Similar to plasma but has less proteins
Lymph
Lymphocytes
Specialized cells that function in defending body
Lymphoid tissues
Collections of loose connective tissue and lymphocytes. Example is tonsils
Lymphoid organs
More complex structures, contains large number of lymphocytes, connected to lymphatic vessels. Example… Lymph nodes, spleen, thymus
Primary lymphoid tissues and organs
The original place where lymphocytes are formed a matured. Example… Red bone marrow and thymus
Secondary lymphoid tissues And organs
Sites were lymphocytes are activated and cloned. Appendix, spleen, lymph nodes, tonsils, mucosa associated lymphoid tissue
Three functions of the lymphatic system
Produce maintain and distribute lymphocytes, return the fluid from peripheral tissues to the bloodstream, distribution of hormones nutrients and waste products
Where are lymphocytes produced
In the red bone marrow and stored in lymphoid organs
What are the smallest lymphatic vessels
Lymphatic capillaries
What do you lymphatic Capillaries do
One-way flow into larger lymphatic vessels, endothelial cells overlap to act as a one-way valve allowing fluids out but not in
What are the similarities/differences between lymphatic vessels and veins
The walls are both similar, both contain valves to maintain one-way flow, contraction of skeletal muscles around lymphatic vessels help the flow, eventually empties into structure is called lymphatic ducts
What are the two lymphatic ducts
Thoracic duct, right lymphatic duct
The thoracic duct collect lymph from where
The lower body and Lt side of body
What is the cisterna Chyli
It lives at the base of the thoracic duct it receives lymph from the inferior part of the abdomen the pelvis the lower limbs by way of the right and left lumbar trunk and the intestinal trunk
The right lymphatic Dicts collects lymph from where
The right side of upper body and Empties into the right subclavian vein
What lymphoedema
Fattic vessels resulting in an effective drainage. Fluid accumulates and the limb becomes swollen and distended
What cells make up about 80% of circulating lymphocytes
T cells
What cells make up about 10 to 15% of circulating lymphocytes
B cells
What cells make up about 5 to 10% of circulating lymphocytes
NK cell
T cells
- Cytotoxic, helper and suppressive
Cytotoxic T cells
Directly attack foreign cells or virus infected cells. Provide cell mediated immunity
Helper T cells
Both stimulate and suppress other T and B cells
Suppressor T cells
Inhibit the activation and function of both T cells and B cells. When they work together, Suppressor T cells and helper T cells establish and control the sensitivity of the immune response
B cells
When stimulated, they differentiate into plasma cells which produce and secrete antibodies. T cells are responsible for antibody mediated immunity. The cells that do not differentiate into plasma cells instead become memory B cells which remain and reserves to deal with future infections
NK cells
“Natural killer” cells that provide innate non specific immunity. Attacked foreign cells, normal cells infected with viruses, and cancer cells. Continually monitor peripheral tissues as part of immune surveillance
What produces lymphoid cells in the red bone marrow
Haemocytoblast
How are lymphoid stem cells produced
One group stays in red bone marrow and makes B cells and NK cells. Second group my grades to thymus and divides to form T cells.
What hormones influence the production of lymphocytes
Thymosins
How long can lymphocytes live for
Five years in the blood spleen lymph nodes and other lymphoid
Mucosa-associated lymphoid tissue
Extremely important in the digestive tract. Ex: tonsils, appendix, peyer patches
Three lymphoid organs
Lymph nodes
Spleen
Thymus
Characteristics of lymph nodes
Small oval organs, multiples grouped together.
Neck armpits and groin
They filter lymph from pathogens.
Destroy pathogens my macrophages and dendritic cells
What vessel drains the lymphatic nodes
Efferent vessels
Thymus
Make T cells
In mediastinum
The spleen
Largest collection of lymphoid tissues
Filters blood not lymph and removed abnormal blood cells
Initiated stimulation of b and T cells
What are the two types of body defences
Innate unity and adaptive immunity
Explain innate immunity
Genetically determined, present at birth, nonspecific defences
Explain adaptive immunity
Not present at birth, specific response to an antigen
Examples of innate defences
Physical barriers Phagocytes Immune surveillance Fever Inflammation
Explain physical barriers as a deffence
Keep hazardous organisms in materials inside the body such as skin and mucous membranes
- lysosomes are important
Phagocytes as a defense mechanism
Cells that surround and engulf objects
Diapedesis - move into tissue by squeezing through capillary cells
Chemotaxis - attracted or repelled by chemicals
Specialized macrophages (2)
Microglia - in CNS
Kupffer cells - in liver
Explain immune surveillance
NK cells mainly involved
Recognize foreign cells and respond quickly. Secret perforins that create holes in The nuclei of these cells therefore killing them
What are cytokines
Chemical messengers
Produce anti viral proteins, interfere with viral replication, slow the spread and stimulate macrophages and NK cells
Histamine and heparin
Produces local swelling, redness heat and pain in response to localized tissue injury
Why do we want a histamine production
Increases blood vessel permeability. Let’s white blood cells move out of blood and into tissues, also let’s plasma leak out ( Edema) and brings more blood flow
Pus is the dead cells
Fever in response to pathogens
Greater than 37.2
Pyrogens: proteins that reset temp centre in Hypothalamus and raise body temp. Mild fever is good - increases metabolism
Adaptive defences respond to…
The presence of specific antigens. Provided by coordinated activities of T and B cells resulting into self-defence specifically against pathogens
Three features of adaptive immunity
Not present at birth, can be active or passive, acquired either naturally or artificially
Adaptive immunity: specificity
Specific defended activated by specific antigens
Adaptive immunity: versatility
Millions of different lymphocytes produced each one with a different antigen receptor
Adaptive immunity… Memory
First exposure triggers development of memory cells second exposure triggers the same cells with a faster and longer lasting immune response
Adaptive immunity… Tolerance
When the immune system does not respond to normal antigens. And ET or B cells that attacked normal antigens are destroyed during differentiation
Two forms of active immunity
Naturally acquired… Develops after exposure to antigens in environment
Artificially induced… Develops after administering an antigen to prevent disease like a vaccine
Naturally acquired passive immunity
Conferred by transferring maternal antibodies across will centre or in breastmilk
Artificially induced passive immunity
Conferred by administering antibodies to combat infection
Aka…. You get an infection so you take an antibiotic
Cytotoxic T cells
Called killer T cells
Cell mediated immunity
Release performing, secret cytokines that activate apoptosis (cell death) and secret lumphotoxins that disrupt target cells metabolism
Helper T cells
Activists by exposure to antigens. Divide into memory and active helper T cells. Active cells secret cytokines
Stimulates both cell and antibody mediated immunity
Memory T cells
Both cytotoxic and helper T cells divide into memory cells. Remain in reserve when second exposure it’s so quick to defend and identify
Regulatory T cells
Suppress response to tiger t and B cells. Secret cytokines called suppression factors. Limit degree of immune response
Epitopes
Antibodies bind to portions of these antigens
5 classes of antibodies
IgG - largest class
IgM - first antibody produced
IgA - exocrine secretions (tears,saliva)
IgE - inflammatory and allergic responses
IgD - attached to B cells aiding in sensitization
Six functions of antibodies
- Naturalization
- Precipitation and agglutination
- Of completion of completion
- Attraction of phagocytes
- Enhancement of phagocytosis
- Stimulation of inflammation
