Haematology Flashcards
What are the Cellular Components of blood?
Erythrocytes (RBC)
Leucocytes (WBC)
Platelets (Thrombocytes)
Blood Constituents -
55% ________
Plasma
Leucocytes and Platelets
Erythrocytes
What is Haematocrit?
The percentage of erythrocytes as proportion of the total blood volume.
(Adult female - 37-47%)
(Adult male - 40-54%)
Erythrocytes (Red Blood Cells (RBC) ) contain millions of molecules of _______________.
Haemoglobin (Hb)
Erythrocytes life-span is ______ days.
Old erythrocytes are destroyed by ________ in liver and spleen.
120.
Macrophages.
Iron from recycled Hb is used to form new RBC.
True or False?
True!
What is Erythropoiesis?
Production of Erythrocytes.
Explain the cycle of Erythropoiesis.
- Too few RBC leads to hypoxia.
- Hypoxia detected by kidney.
- Kidney secretes hormone erythropoietin (EPO).
- EPO stimulates red bone marrow to produce RBCs.
Specific dietary needs are required for Erythropoiesis.
These include……..
Iron - Production of Hb.
Vitamin B12 - Production of DNA.
Folic Acid (Folate) - Production of DNA.
A decrease in Hb in blood (below normal for age and sex), resulting in hypoxia and hypoxaemia is known as ______________.
Anaemia.
Can be due to: Decreased production of RBC, increased destruction of RBC or increased loss of RBC.
Hypoxia secondary to anaemia causes compensatory mechanisms in the _____________ system and the _________ system.
Cardiovascular system - vasodilation, causes increased HR and SV to compensate, can lead to heart failure.
Respiratory system - increased respiratory rate and depth, Dyspnoea.
Typical symptoms of Anaemia include:
Fatigue, Dyspnoea on exertion. Coldness. Pallor. Dizziness. Lips, skin, conjunctivae, nail beds may appear pale. Poor wound healing. Abdominal pain, nausea, vomiting.
(If mild anaemia, symptoms only occur upon exertion).
In Anaemia diagnosis, what do blood tests measure?
Mean cell volume (MCV), size of RBC. Mean cell Hb (MCH), Hb content (can be indicated by colour of RBCs). Total Hb (g/L). Haematocrit. Reticulocyte count (immature cell).
What is Plasma made up of?
Plasma is 90% water, plasma proteins, globulins (Antibodies), clotting factors, electrolytes.
There are many different types of Anaemia.
List the types of Anaemia that occur from Decreased RBC production:
Iron deficiency anaemia
Folate deficiency anaemia
Pernicious anaemia
What type of Anaemia occurs from Increased RBC destruction or loss.
Post haemorrhagic anaemia.
The most common type of Anaemia is ___________.
What are the causes?
Iron deficiency anaemia.
Causes:
Inadequate iron intake (vegan etc.)
Inadequate iron absorption (coeliac).
Increased iron requirement (growth, pregnancy).
Excessive iron loss (bleeding, chemotherapy).
RBC characteristics in Iron deficiency anaemia are:
Microcytic &
Hypochromic.
What do these terms mean?
Microcytic - cells too small.
Hypochromic - cells too pale (not enough iron).
How is Iron deficiency anaemia managed?
Treat cause of blood loss.
Assess body iron status (fingerprint test).
Iron supplements, oral or parenteral (injection).
Folate deficiency anaemia occurs due to inadequate folate intake or increased requirements.
The RBC characteristics are:
Macrocytic &
Normochromic.
What do these terms mean?
Macrocytic - cells too large (don’t fit in tiny vessels).
Normochromic - Normal colour.
Who is at risk of Folate deficiency anaemia?
Alcoholics. Pregnant, lactating females. Malabsorption sufferers. People who don't eat veges. Some medications.
Folate deficiency anaemia should be treated with oral supplements.
What can occur during pregnancy if folate intake is inadequate?
Birth defects.
What is Pernicious anaemia?
Anaemia caused by insufficient intrinsic factor in the stomach. (Inability to absorb vitamin B12 from small intestine).
In Pernicious anaemia, RBC characteristics are:
Macrocytic &
Normochromic.
What do these terms mean?
Macrocytic - cells too large (can’t fit through tiny vessels).
Normochromic - normal colour.
What are the clinical features of Pernicious anaemia?
Typical symptoms of anaemia.
Usually severe on presentation (develops over many years).
Neurological abnormalities may develop;
Numbness, tingling, difficulty walking, confusion, depression.
Who is at risk of Pernicious anaemia?
What are the treatments?
Vegan/vegetarian children.
Elderly (gastric atrophy).
Gastritis sufferers.
Treatment could be high oral doses or injections of vitamin B12.
What is Acute Posthaemorrhagic anaemia?
How is it treated?
Rapid loss of large blood volume from trauma or surgery.
Treatment is blood transfusion.
What is Chronic Posthaemorrhagic anaemia?
What is the treatment?
Slower blood loss. It can cause Iron Deficiency anaemia due to excess menstruated flow or GI bleeding (ulcers, aspirin).
Treatment should be supplemental Iron.
What is Polycythaemia?
Excess RBC production, results in increased blood viscosity. (Eg. EPO administration).
Can also occur through dehydration.
What is Secondary Polycythaemia?
A physiological response to prolonged Hypoxia.
It occurs in:
Individuals with COPD or Heart failure.
Individuals living at high altitude.
Smokers with increased blood levels of carbon monoxide.
Erythrocytes have surface antigens. Surface antigens are cells that ______ _____.
Belong ‘to us’.
Antigens determine major blood groups.
You can only receive blood from a donor which has antigens that __________! (Or no antigens)
You already have
ABO blood groups are based on two Antigens; A and B. AB - A & B B - B only A - A only O - ??
What is O?
Neither A nor B.
Type AB have both antigens. They can receive _______ types: universal recipient.
Type O have neither antigen. They can donate to ___ types: universal donor.
All
All
Rh(D) blood groups are based on Rh(D) antigens (Rhesus factor).
Rh(D)+ has ___________.
Rh(D) - has ___________.
D antigen.
No D antigen.
Blood groups B and A can receive their own blood groups in a transfusion, and they can also receive group O in a transfusion.
Why?
Because O group blood contains neither A or B antigens and is a universal donor.
(You can only receive blood from a donor who has the SAME antigens as you, or no antigens)
Transfusion of mismatched blood causes agglutination of RBCs (clump together) (NOT blood coagulation!).
What are the dangers of this?
Small blood vessels can get blocked.
Haemolysis (break down) occurs.
Release of Hb causes kidney damage.
May be fatal.
Leucocytes form our immune system and protect us from……….,
Bacteria, viruses, parasites, toxins and tumour cells.
