Lecture 7 - white blood cells Flashcards
Neutrophils
- what do they look like?
- what do they contain?
- what do they originate from?
-What does it mean when there are immature neutrophils in blood?
- dense granules (when stain can see) in cytoplasm
- most common ones
- stages of differentiation occur in the marrow
- made from a myeloblast
- myeloblast, promyelocyte, myeloctye, metamyleoctye, band nuetrophil, segmented nuetrophil
- immature forms of neutrophils will spill out into the blood - meaning there is stress, inflammation or cancers of blood
Granulopoiesis control
How many days do they take to mature?
What factors regulates the growth?
what growth factor can you use in clinical practice to increase the maturaiton of neutrophils?
Granulopoiesis - makes granuloctyes (neutrophils, basophils, eosinophils)
7-10 days maturation
- depends on microenvironment
- regulated by haematopoietic growth factors e.g IL3, stem cell factors, GM-CSF, G-CSF
-can use this in clinical practice - G-CSF - increase maturation of nuetrophill
Neutrophil function
What are they attracted to and attatch to?
and then what do they do when they escape and get into tissue? (via what mechanism)
- neutropfils are attracted to chemotaxic factors, and then attatch and get out of blood vessels
- go on to phagaocytose material
- then can kill bacteria - by oxidative and non oxidative mechanisms (release enzymes)
Clinical relevance
What does leucocytosis mean?
What can this indicate?
What does neutropenia mean?
- neutrophil leucocytosis - increase in immature forms of neutrophils in blood - can indicate infection and inflammation
- patients with a low neutrophil count - neutropenia, and are at risk of infection
Monocytes
What does the cytoplasm look like?
What is the precurosor?
What haemopoetic growth factor stimulates this?
what happens when it leaves the tissues?
- how many days does it circulate for?
- what cell does it turn into?
-what other cells in body have this feature
What type of infecitons do these usually combat?
-blue, gray cytoplasm with granules (not much cytoplasm)
- same precursor as neutrophil
- CFU-GM
- monoblast, promonocyte, monocyte
- circulates for 1-3 days (turns to chronic infection)
- enters tissues and turns into a macrophage
- (other related cells - kupffer cells in liver, alveolar macropages)
-parasitic infections
What are the main 3 functions of monocytes?
What molecules can they produce?
- phagocytic cells - but mainly in chronic infection
- e.g intracellular parasites (TB)
- chemotaxis, opsonization, phagocytosis and ingestion, killing of ingested bacteria by fusion with monocytic lysosomal granules
- also synthetic funciton 0 make complemetn, interferons, cytokines, growth factors, prostaglandins
- also have antigen presentation - will present to T cells
Clinical relevance
- what is monocytosis?
- how does this occur?
see increase when there is reactive (chronic infections e.g TB) or malignant things (e.g acute/chronic myeloid leukaemia)
Eosinophils
-shape, colour?
- bilobe (different to granulocytes have more lobes)
- red stained - granules are stained
what is Eosinophilia?
what is this in response to?
Eosinophilia - an increase in the number of eosinophils in the blood, occurring in response to some allergens, drugs, and parasites, and in some types of leukaemia.
we see eosinophils in these reactions ..
- allergic or hypersenstivity reactions - e.g hayefever, astham, drug reactions
- parasitic infestation e.g if have been overseas
Basophils
- what is their appearance
- what reactions are they involved in?
- what do their granules contain?
- what cell do they have a close relationship to?
not very common
- dense purply blue granules
- hard to see bilobed nucleus
- also involved in allergic reactions
- e.g type 1 sensitivity - binding sites for IgE - release granule
- have a close relationship with mast cells
- granules contain contain histamine, and anaphylaxis
What are the 2 Primary lymphoid organs
- lymphoctyes made in bone marrow but mature in primary lymphoid organs
- B cells - bone marrow, T cells - thymus
what are the 4 Secondary lymph organs
after the b and t cells have matured they travel to secondary lymphoid tissues
- lymph nodes
- spleen
- lymphoid tissue through the body e.g gut, respiratory tract,
- bone marrow
- this is where the immune response occurs
Lymph node enlargement
what are the 2 reasons why? and how are they different from each other?
Reactive -usually reactive, part of inflammatory or infective process (viral, local bacterial infection)
-Malignant - lymphoid tissue (lymphoma) or metastatic spread - normally firm and hard non tender lymph nodes
what is Lymphocytosis?
what are the two main causes?
Lymphocytosis - increase no. of lymphocytes
- reactive - generlaly after viral infections e.g
- malignant - chronic lymphocytic leukemia
what is Lymphopenia ?
what can cause this?
-reduction in lymphocytes
HIV infection CD4 positive T helper cells (lose these)
- profound T cell deficit
- opportunist infections
- malignancies
