Belongs to HUBS, Lecture 30: Introduction to immunology and immune system Flashcards
what is immunology
the study of an organism’s immune system in health and disease
the immune system is composed of:
- organs
- cells
- molecules
what is the immune system
organised system of organs cells and molecules that interact to defend the body against disease
examples of diseases affected by immune responses
- infectious disease
- inflammatory disease
- cancer
examples of microbes
- viruses (smallest)
- bacteria
- fungi
- protozoa (biggest)
pathogens are
disease causing microbes
two classifications of immune system organs
- primary/secondary lymphoid organs
activity occurring in primary lymphoid organs
production of white cells (lymphocytes)
activity occurring in secondary lymphoid organs
site where immune responses are initiated
primary lymphoid organs include
- thymus
- bone marrow
thymus function
- ‘school’ for white blood cells called T cells
- developing T cells learn not to react to itself
bone marrow function
source of stem cells that develop into cells of the innate/adaptive immune response
bone marrow stem cells are
pluripotent
secondary lymphoid organs include
- spleen
- lymph nodes
spleen function
site of initiation for immune responses against blood-born pathogens
lymph node location
along lymphatic vessels
lymph node function
- lymph fluid from blood and tissue is filtered
- site of initiation of immune responses
three layers of defence in the immune system
- chemical and physical barriers
- innate ‘arm’
- adaptive ‘arm’
chemical and physical barrier layers
- epidermis
- dendritic cell
- dermis
epidermis composition
dead cells, keratin and phagocytic immune cells
layer of dead cells
dermis composition
thick layer of connective tissue, collagen, blood vessels and phagocytic immune cells
dendritic cell functions
immune cells
chemical defences on skin
antimicrobial peptides
lysozyme
sebum
salt
antimicrobial peptides function
forms pores in microbial cell membranes
lysozyme function
breaks down bacterial cell walls
sebum function
low PH acts as antimicrobial
salt function
hypertonic causes cell to shrivel
mucous membranes layers
- epithelium
- fibrous connective tissue
mucous membrane epithelium composition
highly packed live cells, constantly renewed, mucus-producing goblet cells
location of mucosal membranes
lining parts of the internal body that are exposed to air
mucociliary escalator function
get things we shouldn’t have inhaled out of our system
innate immunity features:
- already in place
- fast acting
- limited specificities
- has no specific memory
adaptive immunity features:
- improves during the response
- slow acting
- highly specific
- has long-term specific memory
innate defences include:
- surface barriers
- internal defences
adaptive defences include:
- humeral immunity (B.cells)
- cellular immunity (T cells)
