Blood & Bleeding Flashcards
What do I need to know about blood?
The purpose of blood – to deliver nutrients and oxygen, and to remove waste,
from cells throughout the body.
Although acting like a fluid, blood is considered a connective tissue made of cells and an extracellular matrix
What is blood made from? Two elements:
1. The extracellular matrix which is plasma – water, nutrients, proteins, electrolytes, dissolved gases and other soluble substances
2. Cellular or formed elements – red blood cells called erythrocytes, platelets
and white blood cells called leukocytes
Where does haemoglobin fit?
* Haemoglobin is a protein found within red blood cells
* The ‘haem’ is the iron portion of blood, the site of oxygen binding
Thinking point – if iron is required to carry oxygen, what might be a clinical sign of lack of iron? (lack of oxygen/anaemia/ low energy/ paleness)
How is blood created?
Life Cycle of a Red Blood Cell
1. Low oxygen stimulates release of erythropoietin from the kidney
2. Erythropoietin stimulates erythropoiesis in red bone marrow (The spleen and liver also have the ability to perform erythropoiesis)
3. Over about 7 days a (beginning red blood cell) myeloid stem cell becomes a proerythroblast, reticulocyte then (full red blood cell) erythrocyte
4. Average lifespan of an erythrocyte is 120 days
5. Macrophages in bone marrow, liver and spleen remove worn out erythrocytes from circulation
Names for red blood cell production but all mean the same thing:
* Erythropoiesis - usual name
* Haemopoiesis
* Haematopoiesis
What is needed for red blood cell production?
Two types of component are needed for healthy red blood cell production:
- General - all new cells need these: Lipids, Amino Acids, Glucose
- Specific - red blood cells/ erythrocytes need these - Iron, Copper, Zinc, B Vitamins
Consider sources of nutrition that are essential to provide these components, and those which actively impair absorption, and also timing of meals
How does the body deal with bleeding?
The meaning of haemostasis- ‘the arrest of bleeding’, consisting of the two component parts ‘haemo’ pertaining to blood, and ‘stasis’ meaning a slowing or stopping.
There are three key stages to this process:
1. When bleeding detected, Vascular spasm or vasoconstriction, to stop blood going to the cut
2. Platelet plug formation to try and plug the gap
3. Coagulation or clotting - Vitamin K is the key vitamin involved in coagulation
Key factors in the clotting process (there are 13 factors in the clotting cascade in all):
* Prothrombin, which activates the enzyme…
* Thrombin which converts inactive….
* Fibrinogen to insoluble fibrin threads which stabilise the platelet plug
The regulated clotting pathway means that only when activated by appropriate factors does clotting occur, preventing coagulation of blood within healthy vessels. All very controlled.
What causes excessive bleeding?
Hypocoagulability. As with its close linguistic companion, homeostasis which is the maintenance of balance of body functions, haemostasis can become disrupted. If the capacity to coagulate is reduced, a
hypocoagulable state arises leading to excessive bleeding.
The following diseases and factors may cause this:
* Haemophilia - Genetic deficiency of clotting factors
* Thrombocytopaenia - Deficiency of platelets (reduced production or increased destruction)
* Liver disease - Multifactorial e.g. decreased synthesis of clotting factors
* Use of anticoagulant drugs - Warfarin is the most well known
Herbal thinking point: What therapeutic considerations might there be for a patient in a hypocoagulable state? (It needs orthodox intervention, but what could a herbalist do?)
What causes incorrect clot formation?
Hypercoagulability - This state is defined as the presence of exaggerated coagulation activity or coagulation in the absence of bleeding, leading to thrombosis with attendant risks of, for example, pulmonary embolism or stroke. Causes may be inherited or acquired
- Inherited – thrombophilia with genetic factors causing mutation and dysfunctional response of clotting factors
- Acquired – surgery, malignancy, infection and inflammation, contraception, pregnancy and hormone replacement therapy, antiphospholipid syndrome (an acquired autoimmune disorder characterised by venous or arterial thrombosis)
What should be considered for a hypercoagulable patient?
What is anaemia - an introduction?
Anaemia – one disease, many causes!!
We will be considering anaemia in more depth in the third video of this lesson, but it is relevant at this point to introduce it and start to think of the variety of different disease processes underlying a single disease presentation.
- Nutritional deficiency (iron, B12)
- Inherited cell defect (intrinsic haemolytic anaemia)
- Extrinsic haemolytic anaemia (autoimmune, malignancy, infection)
- Bone marrow failure (pancytopaenia)
The holistic perspective – anaemia as a condition demonstrates the breadth and
depth of interconnection across the systems and functions of the body, where
digestive health to optimise absorption, reduction of inflammation and treatment of
autoimmune presentations can all contribute to resolution of a single presentation.
