Blood Cells: RBC WBC platelets

Question 1

What are the two major components of blood?

Answer 1

Cells and plasma

Question 2

What percentage of blood is cells in males? females?

Answer 2

40-50%

35-45%

Question 3

Where are the stem cells that differentiate to form different blood cell type?

Answer 3

Bone marrow

Question 4

How many micrometres is a red blood cell?

Answer 4

7

Question 5

Describe what is inside a red blood cell

Answer 5

Lacks nucleus, mitochondria, golgi, ribsomes.
Packed with haemoglobin.
Contains enzymes needed for anaerobic metabolism of glucose.

Question 6

What is the name of the penultimate precursor in bone marrow?

Answer 6

The normoblast

Question 7

Give details on the normoblast

Answer 7

8-10 micrometres
highly condensed nucleus
contains most of the haemoglobin
still has a few mitochondria and ribosomes

Question 8

What happens when maturation of a normoblast occurs?

Answer 8

Nucleus ejected and remainder of cell enters the blood as a reticulocyte. It takes 1-2 days for remaining RNA and organelles to be lost. Reticulocyte count is 1% of total rbc.

Question 9

What is a function of a platelet? What is it diameter?

Where are they produced?

Answer 9

Function = haemostasis (blood clotting) and maintenance of blood vessels. 2-3 micrometres in diameter with a bi - convex shape, no nucleus. They are produced in the bone marrow.

Question 10

Where do platelets adhere to and what does this form?

Answer 10

They adhere to fibrin filaments and damaged endothelial cells forming a blood clot.

Question 11

What is a megakaryocytes?

Answer 11

A giant cell with a large irregular nucleus. All the nuclear content is needed to support all the cytoplasm in the cell. Necessary for blood clotting.

Question 12

What are the two types of classification of white blood cells?

Answer 12

1. Granulocytes (neutrophils, basophil, eosinophil)

2. Mononuclear leukocytes (monocytes, lymphocytes)

Question 13

What is the name for the precursor cell of granulocytes and lymphocytes?

Answer 13

• myeloid (bone-marrow derived)

- lymphoid (originate in bone marrow, mature in tissues such as thymus)

Question 14

Give some details of neutrophils including diameter and lobe number

Answer 14

Neutrophils >90%
12-14um 
Highly lobulated nucleus with 2-5 lobes
Abundant glycogen 
Highly phagocyte and motile
5-90 hours in circulation
Attracted to sites of inflammation
On activation, adhere to receptors on endothelial cells expressed in response to secretion of cytokines

Question 15

What happens to a neutrophil after a single burst of activity?

Answer 15

They die due to limited synthetic capabilities.

Question 16

What do lymphocytes do to get energy?

Answer 16

They rely on glycolysis meaning they have no form of new energy so the neutrophils die after a sudden release of energy.

Question 17

Give details on eosinophils

Answer 17

12-17 micrometres diameter
bi-lobed nucleus
has specific granules
large ovular shape
major role in destruction of parasites
role in the initiation and maintenance of inflammatory responses
leave circulation within 8-12 hours of release from bone marrow

Question 18

Give details on basophils

Answer 18

14-16 micrometre diameter
bi-lobed nucleus
granules containing histamine 
release cytokines when stimulated
closely related to tissue mast cells but from a different precursor

Question 19

Give details on monocytes

Answer 19

largest blood cell (up to 20 micrometres diameter)
Nucleus which is kidney bean shaped
Highly phagocytic and motile 
Leave blood within 2 days of release
Enter tissues to become macrophages
lifespan of months/years

Question 20

What are 4 functions of macrophages?

Answer 20

1. Defence against micro-organisms
2. Refuse - collection for removal of tissue debris, old red blood cells
3. Antigen presentation - displayed on surface and presented to T lymphocytes to tigger an immune response
4. Cytokine secretion

Question 21

Give details on lymphocytes including B and T ones

Answer 21

6-9 micrometres
condensed nucleus occupies 90% of cell
thin rim of cytoplasm
responsible for adaptive immunity

B - surface immunoglobulin for antigen receptor, respond to antigen by proliferating and maturing into plasma cells which then secrete the same immunoglobin

T - receptor for antigen, they secrete cytokines into blood stream

Question 22

Outline the process of haemopoiesis

Answer 22

The process by which mature blood cells are generated from precursor cells.
2-2.5 weeks = earliest red cells are nucleated,
5 weeks = haemopoieses shift to liver
4-5 months = haemopoieses shits to bone marrow

Question 23

Explain the origin of blood cells

Answer 23

All blood cells arise from a common pluripotent stem cells.
This gives rise to unipotent stem cells.
Erythropoietin is what causes the production of erythrocytes.

Question 24

What is plasma composed of?

What pressure does it exert?

What are the main proteins in plasma?

Answer 24

• fluid component of blood
• aqueous solution of salts, nutrients and plasma proteins

Plasma proteins exert a colloid osmotic pressure to help regulate aqueous exchange between plasma and extracellular fluid.

Albumins - involved in transport of hormones, vitamins and enzymes
Globulins - include immunoglobulins
Fibrinogen - precursor or fibrin, important in blood clotting