Red Blood Cells Flashcards
What are RBC’s also known as?
Erythrocytes
How are Erythrocytes Produced?
via erythropoiesis
Where are Erythrocytes Produced and How?
in the bone marrow
- cell size decreases, loses RNA and DNA
- colour change from blue to red
- leaves bone marrow
- nuclei destroyed by macrophages
cell becomes a reticulocyte
after couple days = erthrocyte
Which Hormone Enhances Erythropoiesis?
Testosterone
Which Vitamins are Particularly Needed in Erythropoiesis?
Vitamin B12+B9
List Features and their Advantages from the Morphology of Erythrocytes. (5)
- haemoglobin - carry oxygen
- no mitochondria - more volume for Haemoglobin
- no nucleus - same
- biconcave shape - surface area and flexibility
- 2 alpha chains, 2 beta chains, 4 haem groups
How Large are Erythrocytes and Why?
7.5micrometers in diameter when capillaries are 8micrometers
- allows more surface area for gaseous exchnage
What is a ‘Porphyrin’?
the ring like compound, how erythrocytes are structured
- iron sits in the middle
What are the 3 Types of Haemoglobin?
HbA = most common
HbA2 = small amounts
HbF = foetal haemoglobin
when oxygenated = red
when deoxygenated = blue
What is the Life Span of Erythrocytes?
100-120 days
What is the name for RBC death?
Eryptosis
What Hormone is Released when Erythrocytes are being Destroyed, Why and Where From?
Erythropoietin is released from the kidneys
- in response to hypoxia
- it stimulates rapid maturation of RBC’s
Describe Eryptosis. (4)
- change on the erythrocyte membrane
- detected and engulfed by macrophages
- divided into globin and haem
- destroyed by macrophages in liver, spleen and bone marrow
What Happens to the Globin during Eryptosis?
broken down into it’s amino acids and reused
What Happens to the Haem during Eryptosis and How does it Leave the Body?
broken down into Biliverdin, CO2 and Fe by haem oxidase
- Biliverdin appears green in bruises
Biliverdin broken down into Bilirubin
- in the liver
- stored in the gall bladder
Bilirubin released into the intestines
- transformed into urobilinogen by bacteria
some remains as sterocobilin
- excreted in faeces
some sent to kidneys as urobilin
- excreted as urine
Iron is Released from Haem During Eryptosis, what Happens to it?
binds to tranferrin
- becomes unreactive
- transported to the liver
- becomes ferritin
- binds to aluminum and stored in the gall bladder
- moves out and recirculated
Define Anaemia
decrease in a number of red blood cells or less than the normal quantity
What are the 3 Main Causes of Anaemia?
- excess blood loss
- excess RBC destruction
- deficient RBC production
What are the Common Underlying Causes behind Anaemia (5)
- dietary
- blood loss
- malabsorption
- pregnancy
- parasitosis
Give some Signs and Symptoms to Anaemia (8)
- fatigue
- paleness
- irritable
- light headed
- poor wound healing
- candida infections
- glossitis
- recurring mouth ulcers
Define Pernicious Anaemia.
RBC count drops as intestines cannot properly absorb vitamin B12
What are the Common Causes of Pernicious Anaemia (4)
- autoimmune disease
- tapeworm
- diet
- celiac
What are the Symptoms of Pernicious Anaemia? (8)
- tired
- parasthesia
- dyspepsia
- depression
- weight loss
- neurological
- glossitis
- angular cheilitis
How do you Treat Pernicious Anaemia?
- B12 injections
- oral supplements
What is Haemoglobinopathies?
a group of recessively inherited genetic conditions affecting the haemoglobin component of blood
What is Sickle Cell Anaemia?
- haemoglobin is abnormal
= red blood cells = hard and sticky - look like a C-shape called a “sickle”
How does Sickle Cell Anaemia affect Haemoglobin?
change in amino acid from Glutamine to Valine on position 6
on the beta chain of chromosome 11
= sickle cell
What are the Problems of Sickle Cell Anaemia?
- cause haem molecules to polymerise and clumo
- cant carry oxygen
How is Sickle Cell Anaemia Inherited? How does this Affect Malaria?
autosomal recessive
- if you are a heterozygote, offers protection against malaria as you cant carry infection
How is Sickle Cell Anaemia Treated?
Hydroxyurea to increase HbF production
Difference between Sickle Cell Anaemia and Thallassaemia
SCA = qualitative
Th = quantitative
What is Thalassaemia and the Two Types?
inherited when the body doesn’t make enough haemoglobin
alpha - reduction of alpha unit production
alpha unit = 2 genes, 4 alleles
lose 1 = no problem
lose 2 = mild anaemia
lose 3 = severe anaemia
lose 4 = incompatible with life
beta - reduction of beta unit production
beta unit = 1 gene, 2 alelles
- varying severity
- when the extra units clump together = abnormal RBC
What is Haemolytic Anaemia?
when there is more destruction of RBC than production
