Blood And Blood Cells

Question 1

Where is erythropoietin produced?

Answer 1

It is produced in the kidneys and stimulates erythropoiesis in stem cells in bone marrow

Question 2

Describe the life cell of an erythrocytes

Answer 2

They don’t have organelles so cant synthesise proteins = they have only last 120 days
1. Erythrocytes produced in the bind marrow
2. Immature erythrocytes contain ribosomes = reticulocytes
A lot of reticulocytes = anaemia

Question 3

Types of anaemia and their causes

Answer 3

Microcytic = mensuration (low MCV)
Normocytic = acute blood loss (normal MCV)
Macrocytic = DNA synthesis fails so less division of progenitor cells. Caused by vitamin b12 deficiency and folic acid (high MCV)

Question 4

Describe the structure of haemoglobin

Answer 4

4 polypeptides each with a haem group

Oxidised to form methaemoglobin with Fe3+ instead if Fe2+

Question 5

What do leukocytes do?

Answer 5

Invade tissue space to fight infection

Question 6

Characteristics of polymorphonuclear granulocytes

Answer 6

Segmented nucleus 
Cytoplasmic granules
Release inflammatory signals
Engulf, kill, digest 
Adhere to vessels

Question 7

Role of antibodies

Answer 7

Precipitation
Agglutination
Opsonisation
Neutralisation

Question 8

What are platelets derived from?

Answer 8

Megakaryocytes

Question 9

How are platelets activated?

Answer 9

Platelets have surface receptors to collagen and thrombin
Binds to collagen
Release granules which promote aggregation
Produce thromboxane A2 using cyclooxygenase

Question 10

How does aspirin prevent blood clotting?

Answer 10

Inhibits cyclooxygenase so platelets can’t thromboxane A2 can’t be produced