blood: chapter 19

Question 1

list the 5 functions of blood

Answer 1

1. transport dissolved substances
2. stabilize body temperature
3. defense against pathogens & toxins (white blood cells)
   4.pH regulation)
4. clotting at injury sites (platelets)

Question 2

what are the 3 things that form a pump, conducting system & fluid medium in Cardiovascular system

Answer 2

-pump =the heart
-conducting system =blood vessels
-fluid medium =blood

Question 3

what are the 4 physical characteristics of blood

Answer 3

1, 38 degrees celsius =normal temperature
2. high viscosity
3. slightly alkaline
4. contributes 7% of body weight

Question 4

what is the normal pH of blood

Answer 4

7.35-7.45

Question 5

between males and females, who are expected to have more blood volume

Answer 5

males

Question 6

list 4 components of blood

Answer 6

1.plasma
2.red blood cells
3.white blood cells (leukocytes)
4. Platelets

Question 7

what component of blood is not part of formed elements of blood

Answer 7

plasma

Question 8

what is the function of each formed element of blood

Answer 8

leukocytes- defense/ immune system
platelets- clotting
red blood cells- transport oxygen

Question 9

define the term haematopoisis

Answer 9

process of producing formed elements of blood

Question 10

Define the term Haenatocrit

Answer 10

% of whole blood volume contributed by formed elements of blood

Question 11

how are RBC’s structurally suited for their function (modify the answer when done with chapter 19: blood)

Answer 11

their function is to transport oxygen and structurally they are biconcave disc shaped which allows them to move flexibly in blood vessels and it contains haemoglobin which contains iron that allows oxygen to bind.

Question 12

how does RBCs not having mitochondria help them be suited for the function

Answer 12

their function is to transport oxygen, without mitochondria they undergo anaerobic respiration therefore oxygen is not used up during transportation by RBC’s

Question 13

what are Agglutinogens and what are agglutinins

Answer 13

Agglutinogens are antigens and Agglutinins are antibodies

Question 14

in 3 steps explain what will happen during donation from types B to type A blood transfusion and what do we call this process

Answer 14

1. blood type B antigens will enter blood type A plasma
2. anti-B antibodies will detect and attack the new foreign type B agglutinogens (antigens)
   3.haemolysis will occur

we call this agglutination

Question 15

do the donor’s antibodies attack the recipients antigens during agglutination

Answer 15

No. Antibodies are only active in their home ground lol.

Question 16

what does Rh- or the minus sign on A- mean

Answer 16

it means the D-antigen is absent

Question 17

Is a Rh+ individual born with the D antigen (is it genetically acquired)

Answer 17

Yes the D-antigen is genetically acquired

Question 18

Is a Rh- individual born with the D agglutinin (antibody) (is it genetically acquired)

Answer 18

No its not genetically acquired but is acquired 6months after exposure to Rh+ blood . Without exposure to Rh+ blood it is not possible to acquire it.

Question 19

what is Sensitization

Answer 19

it is when a pregnant Rh- woman is carrying a Rh+ baby and gets exposed to Rh+ blood during giving birth and 6months later develops anti-D antibodies.

Question 20

do anti-D antibodies affect all pregancies a woman has

Answer 20

no, they only start developing and affecting from the second pregnancy.

Question 21

can blood type AB receive and donate to blood type A or blood type B

Answer 21

blood type AB can receive from both blood types A and B but cannot donate to either of them (can only donate to blood type AB) because blood type AB donates a combination not individual A and B ….therefore antibodies will attack and agglutination will occur.

Question 22

an incompatible blood transfusion in terms of Rh factor, does it result in agglutination. Explain

Answer 22

no. it results in sensitization as a consequence (check what sensitization is).

Question 23

if blood of unknown type is donated to a sample of blood that has anti-B antibodies and agglutination doesnt occur, does this mean blood of unknown type has B agglutinogens

Answer 23

no it doesnt. the anti-B antibodies would have affected the B-antigens

Question 24

if blood of unknown type is donated to a sample of blood that has anti-B antibodies and agglutination occurs, does this mean blood of unknown type has B agglutinogens

Answer 24

Yes, correct.

Question 25

what is the first phase of haemostasis and for how long does it last for

Answer 25

Vascular phase lasts for 30min

Question 26

from homework : describe the vascular phase of haemostasis off by heart

Answer 26

answer on the notes (handbook date 21july23)

Question 27

what are the 3 phases of haemostasis

Answer 27

vascular phase
platelet phase &
coagulation phase

Question 28

list (in order) the 4 layers of a blood vessel cross-section

Answer 28

1. endothelial layer with endothelial cells
   2.Basement membrane
2. smooth muscle cells
   4.collagen layer containing fibroblasts

Question 29

what is the first action by endothelial cells and what is the consequence

Answer 29

they contract, exposing the basement membrane to blood stream

Question 30

what are the 3 chemical factors (& their functions) that endothelial cells will secrete when they feel attacked by the injury

Answer 30

1.ADP (adenosin di-phosphate) which stimulates platelet aggregation
2. Tissue factor which promotes the Extrinsic (fast clotting) pathway
3. Prostacyclin which is prostaglandin that inhibits platelet aggregation (because too much of a good thing is bad)

Question 31

what are the local hormones that endothelial cells secrete called

Answer 31

endothelins

Question 32

what 2 things do endothelins do

Answer 32

stimulate smooth muscle contraction and stimulate division of endothelial cells, smooth muscle cells and fibroblasts and this speeds up the repair process.

Question 33

what is the result of smooth muscle contraction

Answer 33

smooth muscle cells contraction leads to local contraction which leads to a decrease in blood vessel diameter to slow down blood loss.

Question 34

Endothelial cells become sticky during the vascular phase of haemostasis. what is the importance of this

Answer 34

to seal off blood flow and stimulate platelet aggregation