Lymphatic and Immune system Flashcards
main structures of Lymphatic system
lymphatic vessels, lymphatic tissues, Bone marrow, lymph fluid
Lymphatic tissues cover
organs and lymphnodes
primary function of Lph system
protect against disease
types of lymphoid cells
phagocytes and lymphocytes
function of lymphoid cells
respond to toxins, environmental pathogens and abnormal body cells
primary Lymph organs
RBM, thymus
secondary lymph tissues
spleen, tonsils, lymph nodules
difference btwn primary and secondary lymph tissues
primary separated from surrounding tissues by fibrous capsule
function of lymphatic tissues
produce maintain and distribute lymphocytes
return fluid and solutes from peripheral tissues to blood
distribute hormones nutrients and waste products
lymph nodules structure
no membrane or fibrous capsule, directly linked to CT, found in intestinal and resp tract
function of lymph nodes
filter and purify before returning lymph to venous circulation
lymph node distribution
found in gut, trachea, lungs and thoracic duct
large LN glands in groin and neck
flow of lymph through nodes
in via Afferent Lvessels, out via efferent Lvessels
T cells form in which structure
thymus
B cells derived from
bone marrow
NK cells derived
bone marrow
function NK cells
kill rogue cancerous cells and virus infected cells
Flow of lymph
interstitial fluid - Lymphatic capillaries - lymphatic vessels - lymphatic trunks - lymphatic ducts
Lymphatic trunks
lumbar, intestinal, bronchomediastinal, subclavian, jugular
lymphatic ducts
thoracic and right lymphatic duct
lymphatic vessel structure
thin walls, many valves, larger diameter, flat/ irregular cross section. start as blind pockets
lymphatic capillaries
located between cells of tissues, merge to form Lvessels
lymphnode circulation involves
lymph flow through series of sinuses
Lnode structure-
afferent vessels, subclavicular space, outer cortex, deep cortex, core (medulla), hilum and efferent vessels
- subclavicular space
contains macrophages and dendritic cells. involves antigen display and antibody synthesis
- outer cortex
contains B cells within germinal centres. involves synthesis of b cells
- deep cortex
dominated by T cells, antigen presenting
- core/ medulla
contains B cells and plasma cells organised into medullary cords
Formation of lymph
- blood plasma filtered from capillaries into interstitial space to form interstitial fluid
- absorbed by Lcapillaries, passed into A LV
- lymph enters Lnodes via A LV
- nodes filter lymph, phagocytosis and immune reactions occur
- lymph leaves via E LV valves ensure one way flow
- Lymph into Lducts
- ducts empty into junction of subclavicular and jugular veins
Production of lymphocytes
haemocytoblasts in RBM = lymphoid stem cells
LSC migrate and mature depending on environment
LSC in Thymus
interact with Thymus hormones, differentiate into T cells. Involved in cell mediated immunity
LSC in BM
interact with Interleukin-7 differentiate into B cells. involved in antibody mediated immunity and immunilogical surveillance
Innate immunity
non specific defense
adaptive immunity
specifc defense
innate/ non spec function
block and attack pathogens, present from birth, no memory
adaptive function
identify, attack and develop immunity to specific antigen, acquired in response to antigens
7 types of innate immunity
- physical barriers
- phagocytic cells
- immunilogical surveillance
- interferons
- complement system
- inflammation
- fever
types of adaptive immunity
cell mediated and humoral
cells involved in cell mediated immunity
cytotoxic T cells and Helper T cells
cells involved in humoral immunity
B cells
