Lymphatic System Flashcards
What are functions of the lymphatic system?
It provides blood pressure in capillaries and maintains normal blood volume
It defends the body from microorganisms and physical trauma by acting as a “Helper system” for the CVS and immune systems
What is lymph?
Basically filtered plasma
What are the three parts of the lymphatic system?
Lymph (Fluid)
Lymphatic vessels (Capillaries, vessels, ducts) (Drain into the R/L subclavian veins)
Lymphoid tissues (Lymph nodes, tonsils, spleen, MALT) and organs (Thymus, bone marrow)
How do lymphatic vessels compare to veins?
They have thinner walls
They have larger lumens (diameter)
There are no easily identifiable tunics
They have more permeability
They also have valves
What is the flow of lymph?
Capillaries, vessels, trunks, ducts
What are the five lymphatic trunks?
Lumbar
Interstinal
Brochomesiastinal
Subclavian
Jugular
What’s the difference between the two lymphatic ducts?
The right lymphatic duct only drains 1/4ish of the body on the upper right side but the thoracic duct (the larger one) drains the rest of the body
What are the primary cells of the lymphoid system called?
Lymphocytes
What do lymphocytes do?
They respond to bacteria and viruses, abnormal body cells (cancer cells), foreign proteins and toxins released by some bacteria
What are the three types of lymphocytes?
T cells (Thymus-dependent cells)
B cells (bone marrow-derived cells)
NK cells (Natural killer cells)
Where do T cells come from? Where do they go to be activated?
Bone marrow then they travel to the thymus gland to be activated by thymosin
What are the types of T cells?
Cytotoxic T cells (attack foreign cells and viruses)
Helper T cells and suppressor T cells (coordinate immune response)
Memory T cells (Become active if same antigen appears in the body at a later date)
Where are B cells made? Where do they mature?
They are made and achieve immunocompetentcy in bone marrow
What are the two types of the B cells?
Plasmocytes (produce antibodies that react with antigens)
Memory B Cells (Become active if the same antigen appears at a later date
What are NK cells also called?
Immunological surveillance cells
What is cell mediated immunity?
Direct cell to cell attack, known as cellular immunity
What is antibody mediated (humoral) immunity
The release of antibodies to bind to antigens on foreign cells
Where is lymphoid tissue found?
It’s found in between the connective tissue
Where are the areas of high concentration of lymph nodes in the body?
Cervical area
Axillary area
Breasts
Abdominal region
Inguinal area
What are the parts of a lymph nodes?
Capsule with afferent vessels
Subcasular space
Outer cortex
Germinal center
Medulla
Medullary cords
Hilum with efferent vessels
What does the cortex of the thymus do?
It receives stem cells and produces T cells from them and then sends them to the medulla of the thymus
What does the medulla of the thymus do?
It stores the T cells that remain inactive until needed
What are facts about the spleen?
It is the largest lymphoid organ
It is on the left edge of stomach
It consists of three parts
- Capsule
- Red Pulp (contains lots of blood)
- White Pulp (forms lymphoid nodules)
What happens to the lymphatic system as we age?
T cells become less responsive to antigens
B cells become less responsive
Thymus gland diminish in size
Where do all lymphatic vessels drain into?
The subclavian veins
What is strep throat also called?
Tonsillitis
