The Lymphatic System Flashcards
What is immunity and resistance?
It is the ability to use body defences to ward off diseases or damage
What are the 2 types of immunity?
Innate and adaptive
What is innate immunity?
These are the defences that are present at birth. They are always available and will provide rapid responses to protect us against disease
What is adaptive immunity?
These are the defences that involve specific recognition of a microbe. It response to a specific microbe that it adapts to or it adjusts to handle that specific microbe
What is a lymphocyte?
A white blood cell that participates in the immune response
What are the 2 lymphocytes found in adaptive immunity?
T Lymphocytes (T cells) and B lymphocytes (B cells)
What does the lymphatic system consist of?
Lymph vessels including - lymphatic capillaries, lymphatic vessels and lymphatic trunks and ducts.
Organs - lymph nodes, tonsils, spleen, thymus, red bone marrow and appendix
What is lymphatic tissue?
It is a specialised form of connective tissue that contains a large number of lymphocytes
What are the 3 primary functions of the lymphatic system?
1 - drains excess interstitial fluid
2 - transports dietary lipids
3 - carries out immune responses
How is interstitial fluid formed?
Components of blood plasma filter out from blood capillary walls to form the fluid
What do lymphatic vessels begin as?
lymphatic capillaries in tissue spaces between cells.
What do lymphatic capillaries merge to form?
lymphatic vessels
What flows through the lymph nodes?
Lymph
What are located in intervals along the lymphatic vessels?
Lymph nodes
What drains into the thoracic duct from the lymphatic vessels?
Lymph
What does the thoracic duct empty it’s lymph into?
Into the left internal jugular and the left subclavian vein.
Where does the lymphatic vessel empty it’s lymph into?
The thoracic duct or the right lymphatic duct
What does the right lymphatic duct empty it’s lymph into?
The right internal jugular or right subclavian vein.
What is a lymph node?
Masses of B and T cells surrounded by a capsule
What are the 2 pumps that bring back venous blood to the heart to maintain the flow of lymph?
Respiratory pump and skeletal muscle pump
What are primary lymphatic organs for?
They are the sites where stem cells divide and develop into mature T and B cells.
What are 2 primary lymphatic organs?
Red bone marrow and the thymus
What do the stem cells in the red bone marrow do?
Mature the B cells
What do the stem cells in the thymus do?
Mature into functioning T cells
What are the secondary lymphatic organs?
Lymph nodes, spleen and lymphatic nodules
What happens at the secondary lymphatic organ sites?
This is where the immunity responses occur
What is the thymus?
And what does is contain?
This is a 2 lobed organ that is located posterior to the sternum and medial to the lungs.
It contains large numbers of T cells and macrophages
What do lymph nodes contain?
B cells that develop into plasma cells, T cells, dendritic cells and macrophages.
How does lymph go through the lymphatic vessels?
They enter through the afferent lymphatic vessels and exits through the efferent lymphatic vessels
What is the spleen?
It is the largest single mass of lymphatic tissue. It lies between the stomach and the diaphragm. It contains 2 types of tissue - the white pulp and the red pulp
What are the 2 types of tissue found in the spleen?
The white pulp which is where the B and T cells carry out the immunity responses
The Red pulp which is blood filled sinuses where worn out blood cells and platelets are removed
What is a pathogen?
A disease causing organism - bacteria, viruses, fungi and parasites
What is an antigen?
A substance that induces the production of antibodies
What is an antibody?
An immunoglobulin that binds to specific antigens to facilitate their breakdown and removal from the body
What is an allergen?
An inert antigen capable of inducing an allergic reaction
What are some physical barriers in immunity?
- acid in the stomach
- intact skin
- coughing and sneezing
- mucus in the lungs and digestive system
- acid in sweat
- bacteria in genital tract
- cilia in respiratory tract
- enzymes in tears
What is the first line of defence in the innate immune system?
The skin and mucous membranes
What are the external barriers for innate immunity?
The skin and mucous membranes which have physical and chemical barriers
What are the internal barriers for innnate immunity?
- Antimicrobial substances, natural killer cells, phagocytes, inflammation and fever
What’s the second line of defence for innate immunity?
The internal barriers including - Antimicrobial substances, natural killer cells, phagocytes, inflammation and fever
What are 4 main types of antimicrobial substances?
- interferons
- complement system
- ironing-bindings proteins
- antimicrobial proteins (AMPs)
What happens if microbes penetrate the skin and mucous membranes or bypass the antimicrobial substances in the blood?
It goes to the next level response which is phagocytes and natural killer cells
What is inflammation?
It is a nonspecific defensive response of the body to tissue damage
What is a fever?
It is an elevated body temperature that intensifies the effects of interferons which inhibits the growth of some microbes and speeds up the reactions that aid repair
What is the function of the Epidermis of skin?
Forms physical barrier to the entrance of microbes
What is the function of Mucous membranes?
Inhibit entrance of many microbes, but not as effective as intact skin
What is the function of Mucus?
Traps microbes in respiratory and gastrointestinal tracts
What is the function of Hairs?
Filter out microbes and dust in nose
What is the function of the Cilia?
Together with mucus, trap and remove microbes and dust from upper respiratory tract
what is the function of the Lacrimal apparatus?
Tears dilute and wash away irritating substances and microbes
what is the function of the Saliva?
Washes microbes from surfaces of teeth and mucous membranes of mouth
What is the function of Urine?
To wash microbes from the uretha
what is the function of Defecation and vomiting?
to Expel microbes from body
What is the function of Sebum?
Forms protective acidic film over skin surface that inhibits growth of many microbes
What is the function of Lysozyme?
Antimicrobial substance in perspiration, tears, saliva, nasal secretions, and tissue fluids
What is the function of Gastric juice?
Destroys bacteria and most toxins in stomach
What is the function of Vaginal secretions?
Slight acidity discourages bacterial growth; flush microbes out of vagina
What is the function of Interferons (IFNs)?
Protect uninfected host cells from viral infection
What is the function of Complement system?
Causes cytolysis of microbes; promotes phagocytosis; contributes to inflammation
What is the function of Iron-binding proteins?
Inhibit growth of certain bacteria by reducing amount of available iron
What is the function of Antimicrobial proteins (AMPs)?
Have broad-spectrum antimicrobial activities and attract dendritic cells and mast cells
What is the function of Natural killer (NK) cells?
Kill infected target cells by releasing granules that contain perforin and granzymes; phagocytes then kill released microbes
What is the function of Phagocytes?
Ingest foreign particulate matter
What is the function of Inflammation?
Confines and destroys microbes; initiates tissue repair
What is the function of a fever?
Intensifies effects of interferons; inhibits growth of some microbes; speeds up body reactions that aid repair
What is Adaptive Immunity?
It produces specific types of cells or specific antibodies to destroy a specific Antigen.
What is an Antigen?
It is anything that the body recognises as foreign.
What are some examples of antigens?
Pollen, Foods, Microbes, Drugs, Bacteria, and Viruses.
What does adaptive immunity involve?
It involves lymphocytes called B cells and T cells. Both develop in the primary lymphatic organs.
What are the 2 types of adaptive immunity?
1) cell-mediated immunity
2) antibody-mediated immunity
What does antibody-mediated immunity involve?
B cells transform into plasma cells, then into antibodies
What does cell-mediated immunity involve?
cytotoxic T cells directly attack invading antigens
What are the 3 types of T cells?
1) Killer/cytotoxic T cells
2) Help T cells
3) Memory T cells
What do Killer/cytotoxic T cells do?
- Kill Target cells
- Kill those cells that are infected with a virus or cancer
What do helper T cells do?
- Secrete Cytokines
- Help coordinate other immune cells
What do Memory T cells do?
Remains in lymphatic tissue and recognises the original invading antigen, even years after the first encounter.
What are the 3 types of B cells?
1) Naive B cells
2) Plasma B cells
3) Memory B cells
What do Naive B cells do?
- They have to be activated by coming into contact withthe specific antigen
What do Plasma B cells do?
- They are the Antibody factory
- They make a lot of Antibodies then die
What do Memory B cells do?
They are ready to produce a more rapid and forceful secondary response should the same antigen enter the body in the future
What is the difference between primary and secondary response?
The primary response is slower and not as strong as the secondary response.
This is because of the lack of Memory cells.
What is a vaccination?
Its putting a whole or part of a dead or weakened pathogen into the body
What happens after the 1st and 2nd vaccination?
After the first vaccination, you develop a primary response. After the 2nd vaccination, you develop a secondary response.
Why do you have to have annual boosters for vaccinations?
This is because after time the secondary response can go down and having a booster can bring the secondary response back up.
What are RNA vaccinations for?
They are to get our bodies to make the antigens
