Blood Flashcards
What are the components of blood?
Plasma; clotting/coagulation factors, albumin, antibodies
Buffy coat; platelets, white cells/leucocytes
Red blood cells
What are the functions of blood?
Transport
Maintenance of vascular integrity
Protection from pathogens
Describe transport in blood
Red blood cells transport gases: CO2 and O2
Plasma transports nutrients, waste and messages
Describe blood involvement in maintenance of vascular integrity
Prevention of leaks; platelets and clotting factors
Prevention of blockages; anticoagulants and fibrinolytics
Describe blood involvement in protection from pathogens
Phagocytosis and killing; granulocytes/monocytes
Antigen reception and antibody formation; lymphocytes
What are some haematological abnormalities and how can they occur
High levels;
- raised production
- (decreased rate of loss)
Low levels
- decreased production
- increased rate of loss
Altered function
Describe stem cells
Totipotent
Self-renewal
Home to marrow niche
Binary fission and flux through differentiation pathways amplify numbers
Flux regulated by hormones/growth factors
What is the anatomy of bone marrow?
Where is it?
- bones; mostly in children, axial in elderly
What does it look like?
- stroma and sinusoids
Describe erythroid differentiation
Erythroblast - reticulocyte - erythrocyte
Erythropoeitin; made in kidney in response to hypoxia
Where is erythropoetin made?
kidney
What is the reticulocyte count?
A measure of red cell production
What are consequences of anaemia?
poor gas transfer; dyspnoea, fatigue
What are haematinics?
iron folate vit B12
Deficiency in anaemia
How many RBCs can you make in a day?
~10g/L/day
What is the function of platelets?
Haemostasis and immune
How is production of platelets regulated?
By thrombopoetin
- produced in liver- regulation by platelet mass feedback
- agonists (romiplostim, eltrombopag) used therapeutically
What is the lifespan of platelets?
7 days
What is the function of neutrophils?
Ingest and destroy pathogens, especially bacteria and fungi
Interleukins (between white cells) and CSFs (colony stim factors)
Regualtion by immune responses; macrophages, IL-17
What is the lifespan of neutrophils?
1-2 days
What is the response speed of neutrophils?
few hours
Describe neutrophil differentiation
- Blast
- Promyelocyte
- Myelocyte
- Metamyelocyte
- Neutrophil
When does neutrophilia occur?
Infection
Inflammation; MI, post-op, rheum arthritis
Production regulated by granulocyte-colony stim factor
When is G-CSF used therapeutically?
Granulocyte- colony stim factor
Used in neutropenia and mobilisation of stem cells
What causes neutropenia?
“racial”
Decreased production; drugs, marrow failure
Increased consumption; sepsis, autoimmune
Altered function; chronic granulomatous disease
