Blood Cell Formation and Function

Question 1

What is the intracellular substance of blood?

Answer 1

Plasma

Question 2

What is the cellular substances of blood?

Answer 2

RBC - erythrocytes WBC - Leukocytes Platelets - derived from cells that are no longer cellular

Question 3

What is plasma?

Answer 3

-Rich in protein - albumin, globulins, Ig, fibrinogen = clotting -Regulatory substances, nutritional substances, salts, waste - Removal of fibrinogen-fibrin - serum

Question 4

What percentage of blood is made up of plasma?

Answer 4

~55%

Question 5

What percentage of blood is RBC?

Answer 5

~45%

Question 6

What is the purpose of plasma in the blood?

Answer 6

-Transport mechanism

Question 7

What is the biggest component that makes up blood?

Answer 7

90-92% water 6-7% proteins 2-3% fats, carbs, electrolytes, gases, chemical messengers

Question 8

What are the two categories of blood cells?

Answer 8

1) Red blood cells = erythrocytes 2) White blood cells = leukocytes

Question 9

Are there more red or white blood cells found in blood usually?

Answer 9

Red, but the exact number varies in an individual

Question 10

What are the 2 main components that make up erythrocytes?

Answer 10

water = 60% Haemaglobin = 40%

Question 11

True or false mammalian RBC have no nucleus

Answer 11

True - except when foetus (lose after birth)

Question 12

What colour do RBC stain?

Answer 12

Eosinophilic

Question 13

What are the functions of RBC?

Answer 13

Carrying O2, CO2 and H+ around the body - buffering role

Question 14

What are reticulocytes?

Answer 14

They are immature red blood cells - make up ~1% of red cells in the human body

Question 15

how long do reticulocytes circulate before they develop into mature RBC?

Answer 15

About 1 day

Question 16

Who’s RBC is this?

Answer 16

Avian

Question 17

Who’s RBC is this?

Answer 17

Sheep

Question 18

Who’s RBC is this?

Answer 18

Camel

Question 19

Do we know why mammalian RBC lose their organelles?

Answer 19

No

Question 20

What are the groups that carrying the oxygen in RBC?

Answer 20

Haem - made up of 4 subunits that can each carry 2 O2 so lots of carrying potential

Question 21

How is CO2 carried in blood?

Answer 21

CO2 diffuses across endothelial cells into blood (driven by high CO2 levels in tissues) - most is transported by the RBC as bicarbonate ions (64%) or combined with haemoglobin (21%) or dissolved in erythrocytes (4%) - Plasma only carries a bit 6% dissolved and 5% converted into bicarbonate ions

Question 22

What are thrombocytes?

Answer 22

Platelets

Question 23

What is the arrow pointing to?

Answer 23

Platelets

Question 24

What are thrombocytes involved in?

Answer 24

Essential for haemostasis = clotting

Question 25

Where are platelets from?

Answer 25

Megakaryocytes = bud off from Resevoir in spleen

Question 26

What is the lifespan of platelets?

Answer 26

8-10 days

Question 27

What is the structure and composition of platelets?

Answer 27

-small, ovoid bodies - granules

Question 28

What are the 2 types of blood clotting thrombocytes are involved in?

Answer 28

1) aggregation: platelet adherence - epi cell injury = platelet plug 2) Coagulation: fibrin formation - larger site wounds

Question 29

What are the steps to blood coagulation?

Answer 29

injury triggers two events: 1) the activation and deposition of platelets at a wound site 2) Activation of coagulation pathway: - prothrombin converted to thrombin - thrombin causes fibrinogen to polymerize into fibrin 3) lead to the formation of a fibrin seal on the deposited platelets 4) "plugs the leak"

Question 30

What is a differential cell count?

Answer 30

Morphological examination = general health of the animal

Question 31

What does haematocrit (Hct) measure?

Answer 31

Packed cell volume (PCV)

Question 32

What factors could change plasma levels?

Answer 32

-Dehydration = make haematocrit appear larger than it is - mask anaemia - increase in pregnancy can mimic anaemia

Question 33

How long do RBC last in the body?

Answer 33

100-120 Days Highest cells produced rate as well as longest lifespan

Question 34

What does Multipotent Stem cell mean?

Answer 34

They can form any blood cell line -myeloid and lymphoid

Question 35

How do multipotent stem cells differentiate?

Answer 35

-controlled by lineage-independent and lineage-specific cytokines and grown factors

Question 36

What is the role of haemopoiesis?

Answer 36

1) to maintain homeostasis 2) enable a rapid response to life-threatening conditions: - blood loss (RBC numbers are tightly regulated) - Infection (WBC numbers increase to fight infection) 3) Remove and replace dangerous cell types: - Neutrophils and Eosinophils

Question 37

Where is the site of haemopoiesis in Adult animals?

Answer 37

- Bone marrow = proximal ends of femurs, pelvic flat bones, vertebrae, skull, ribs and sternum

Question 38

What regulates haemopoietic stem cells?

Answer 38

Lots happening but the receptor binding controls gene expression and directs the development Differentiation triggered by: depends on signal molecules

Question 39

What triggers Erythropoiesis?

Answer 39

Hypoxia

Question 40

What controls Erythropoiesis?

Answer 40

Erythropoietin that is produced by fibroblast-like cells in the cortex and outer medulla of the kidney

Question 41

How does EPO control Erythropoietin?

Answer 41

-Shortens the cell cycle time -increases the rate of maturation -Increased rate of release from bone marrow = increases presence of circulating reticulocytes

Question 42

what is a indication of recent increase in erythropoiesis?

Answer 42

Increased presence of circulating reticulocytes

Question 43

Where is erythropoietins made?

Answer 43

Kidneys!

Question 44

What is Anaemia?

Answer 44

A disease of erythrocytes: reduction in the ability of blood to carry oxygen = too few RBC or low haemoglobin levels in RBC

Question 45

What is Polycythaemia?

Answer 45

Disease of erythrocytes: excessive number of RBC = bone marrow cancer or moving in high altitudes