Blood Components

Question 1

Function of Blood (3)

Answer 1

Transportation (gases, heat, nutrients, waste)
Protection
Regulation

Question 2

Formed elements (3)

Answer 2

RBCs
WBCs
Platletes

Question 3

Haemopoesis

Answer 3

= development of formed elements of blood

Question 4

Site of haemoposesis before birth?

Answer 4

1st in yolk sac…later in spleen, thymus + lymph nodes of foetus

Question 5

Main site of haemopoesis (last 3 months before birth)

Answer 5

red bone marrow

Question 6

Describe red bone marrow

Answer 6

Highly vascularised connective tissue

In macroscopic spaces between trabeculae

Question 7

0.05-0.1% of red bone marrow =

Answer 7

= PLURIPOTENT STEM CELLS

Question 8

PLURIPOTENT STEM CELLS (derivative + function)

Answer 8

Derived from mesenchyme (tissue from which almost all connective tissue develop)

Have capacity to develop into many different types of cells

Question 9

Red to Yellow Bone Marrow Transition?

Answer 9

All RED in newborns

As person ages rate of blood cell formation decreases

Red bone marrow in long bones becomes inactive (replaced with YELLOW bone marrow)

Question 10

What can pluripotent stem cells divide into (what can they develop into?)

Answer 10

Myeloid Stem Cells (develop into: platelets, WBCs, RBCs)

Lymphoid Stem cells (develop into lymphocytes)

Question 11

Precursor cells?

Answer 11

“…blasts”
Over several divisions
Develop into formed elements of blood

Question 12

Progenitor cells? (what can they become)

Answer 12

No longer capable of reproducing themselves
Some becoming colony-forming units (CFU)
Become other types of blood cell but not themselves?

Question 13

Name 3 types of Hematopoietic Growth Hormones

Answer 13

Erythropoietin (EPO)

Thrombopoietin (TPO)

Cytokines

Question 14

Function of erythropoietin

Answer 14

Increases no. of red blood cell precursors

Mainly in kidneys

Question 15

Function of thrombopoietin

Answer 15

Hormone produced by liver

Stimulates platelet formation

Question 16

Function of cytokines

Answer 16

Regulate development of different blood types

Small glycoproteins
Act as local proteins

Stimulate proliferation of progenitor cells
Regulate non-specific immune cell activities + immune responses

Cytokine Families (stimulate WBC formation) 
(Colony-stimulating factors, Interleukins)

Question 17

Why do males have higher hematocrits?

Answer 17

Higher due to higher levels of testosterone

Stimulates erythropoietin = stimulates production of RBCs

Question 18

Anemia vs Polycythemia

Answer 18

Anemia = lower hematocrit than normal

Polycythemia = abnormally high hematocrit (>65%)
Raises blood viscosity + blood pressure (due to increases resistance to flow)

Question 19

RBCs plasma membrane

Answer 19

Strong flexible plasma membrane

Allows them to deform without rupturing (when squeezing through narrow capillaries)

Question 20

What causes different blood types?

Answer 20

different glycolipids

Question 21

Pro + Con of RBCs lacking nucleus + organelles

Answer 21

Cant reproduce / carry out metabolic activities

More room to carry O2

Question 22

Structure of haemoglobin

Answer 22

Contains proteins (haem)
4 polypeptide chains (2 alpha, 2 beta) 

Contain ring like non-protein pigment (heme) bound to each of 4 chains

Centre of heme ring = Fe2+

Question 23

RBCs contain enzyme carbonic anhydrase which catalyses…

Answer 23

CO2 + H2O → ← H2CO3 → ← H+ + HCO3-

Question 24

How to tell the difference between granular + agranular WBCs?

Answer 24

(Granular = …“phil” )

Agranular =… “cyte”

Question 25

How do WBCs leave the bloodstream?

Answer 25

Roll along vessel + stick to endothelium | Squeeze between endothelial cells

Question 26

Adhesion Molecules in WBCs (+ selectins and integrins)

Answer 26

Help WBCs to stick to endothelium “selectins” = displayed on surface of endothelial cells (Response to injury + inflammation) Stick to carbs on surface of neutrophils Cause them to slow down + roll “Integrins” = tether neutrophils to endothelium

Question 27

Chemotaxis (neutrophils + macrophages) + stimulus

Answer 27

= Different chemicals released by microbes (attract phagocytes) Stimuli for chemotaxis = kinins (specialised products of damaged tissues)

Question 28

Defensins (neutrophils + macrophages) + action

Answer 28

= Proteins in neutrophils Board range of antibiotic activity Form peptides spears (poke holes in microbe membrane) Loss of cellular contents = kill invader

Question 29

Action of eosinophils

Answer 29

Released by enzymes combatting substances involved in inflammation Phagocytosis antigen-antibody complexes

Question 30

Action of basophils

Answer 30

Leave capillaries at inflammation site (enter tissues) Enter tissues + release granules Contain heparin, histamine + serotonin Intensify inflammation

Question 31

Mast Cells

Answer 31

Release substances involved in inflammation | Widely dispersed in connective tissues

Question 32

Main types of lymphocyte + function (3)

Answer 32

``` B cells (destroy bacteria + inactivate their toxins) T cells (attack infected cells + tumour cells) NK cells (natural killer) ```