Blood

Question 1

What blood cells have a survival rate of 10 days?

Answer 1

Platelets

Question 2

How can the survival time of lymphocytes vary?

Answer 2

It can be anywhere between 1 day and years.

Question 3

What happens in the bone marrow?

Answer 3

This is the site of blood cell production. Cells come from trabeculae of bone and mature in the bone marrow.

Question 4

What problem with bone marrow can affect blood cell production?

Answer 4

Bone marrow stroma can become fibrotic. When this happens blood cell production can happen in the spleen.

Question 5

Where is bone marrow mainly found in adults?

Answer 5

Pelvis, skull and sternum.

Question 6

What is the name of the chemicals which stimulate Haemopoesis?

Answer 6

Cytokines.

Question 7

What can be said about blood cell lineages?

Answer 7

All blood cells are produced from the same progenitor stem cell, but daughter cells gradually differentiate into more and more specific lineages.

Question 8

What are the functions of an Erythrocytes?

Answer 8

Erythrocytes are red blood cells. They deliver oxygen to tissues and maintain osmotic equilibrium. They are carriers of haemoglobin.

Question 9

What happens to red blood cells as they mature?

Answer 9

They loose their nucleus and therefore their ability to make new proteins.

Question 10

What are the two metabolic pathways which occur in red blood cells?

Answer 10

Embden Meyerhof pathway - glucose is metabolised to lactate and the heroes monophosphate pathway where glucose 6 phosphate produces NADPH

Question 11

What stimulates erythropoesis?

Answer 11

When there is a drop in O2, this stimulates increased production of erythropoietin (hormone) which leads to production and maturation of red blood cells and haemoglobin rises.

Question 12

Where are red blood cells broken down?

Answer 12

In the liver into bilirubin which is then excreted via the kidney as urobilirubin.

Question 13

What is a megakaryocyte?

Answer 13

This is a cell found in the bone marrow which platelets bud off.

Question 14

What is the most commonly seen function of platelets?

Answer 14

This is in the clotting cascade. Platelets can adhere to each other, connective tissue and the phospholipid bilayer via their glycoprotein receptors.

Question 15

How are platelets involved in the clotting cascade?

Answer 15

Platelets lead to clotting factor activation which causes a fibrin mesh to form and trap platelets and red blood cells.

Question 16

What stimulates neutrophil production? What other effect does this chemical have?

Answer 16

G-CSF. It also reduces the time for the cells to mature and enhances chemotaxis and phagocytotic killing of pathogens.

Question 17

What are monocytes?

Answer 17

These are cells which migrate to tissues as a response to antigenic stimulation and inflammation. They move through intact Capillary walls (diapedesis) and contain lysosomes to phagocytise the pathogen.

Question 18

What is an eosinophil?

Answer 18

These contain granules which phagocytosis antigen antibody complexes.

Question 19

What four substances are found in the granules in basophils?

Answer 19

Hyaluronic acid, histidine, heparin and seratonin.

Question 20

What two cell types are involved in allergic response?

Answer 20

Basophils and eosinophils.

Question 21

What can be said about the cytoplasm of lymphocytes?

Answer 21

It is non granular.

Question 22

What is the survival rate of a red blood cell?

Answer 22

120 days

Question 23

What cell produces B lymphocytes?

Answer 23

Plasmablasts in the bone marrow.