Lecture 23

Question 1

How much blood in the human body?

Answer 1

its about 7% of the body weight
5L in a 70kg male
4L in a 58kg female

Question 2

What is blood and what is it made up of?

Answer 2

a connective tissue
- 58% plasma (1/4 of body ECF) containing vitamins, proteins and ions
- 42% Cellular Elements red and white blood cells and transported round the body
- 1% platelets used in clotting and hemostasis

Question 3

The layer of platelets is known as…

Answer 3

the Buffy layer

Question 4

Hematopoeisis

Answer 4

the synthesis of blood in red bone marrow in flat bones and proximal ends of long bones

Question 5

Lifespan of red and white blood cells

Answer 5

• 120 days for red blood cells (25% bone marrow production)
• 6-12 hours for white blood cells (75% of bone marrow production)

Question 6

What is the name of the precursor cell for all white. red and platelets

Answer 6

pluripotent hematopoitetic stem cells

Question 7

what are cytokines?

Answer 7

proteins that are released from a cell to signal another

Question 8

Where are the cytokines released and what do they affect?

Answer 8

Erythropoietin (EPO) - released from the kidneys to increase red blood cell growth
Thrombopoietin (TPO) - productions of platelets signalled from liver
Interleukins - all types of cells prompted from fibrocytes in the bone marrow

Question 9

Hypoxia

Answer 9

low O2 in the blood

Question 10

hemoglobin

Answer 10

2 alpha and beta dimers forming a tertramer with binding cooperatvity
each heme have a porphyrin ring that contains Fe

Question 11

Anemia

Answer 11

low RBC count by accelerated loss of blood or decreased production

Question 12

examples of accelerated RBC loss

Answer 12

• blood loss
• hemolytic anemia
• genetic like sickle cell
• acquired like malaria

Question 13

examples of decreased RBC production

Answer 13

• aplastic anemia from drugs or radiation
• dietary insuffciencies iron, folic acid and vitamin b12

Question 14

Difference between Hemostasis and Hemapotesis

Answer 14

Hemostasis - keeping blood inside the blood
Hemapotesis - production of blood cells

Question 15

the 4 stages of hemostasis

Answer 15

1) Vasoconstriction
2) Platelet Plug Formation
3) Coagulation (formation of clots)
4) Dissolution of the clot (fibrinolysis)

Question 16

Explain Vasoconstriction

Answer 16

paracrine signal for a release of norepinephrine which will go to the alpha 1 receptors on the smooth muscles and cause ca2+ to be released allowing for constriction

Question 17

Explain platelet plug formation

Answer 17

planets constantly flow in the blood, when a cut appears, they stick to the exposed collagen.

Question 18

explain coagulation

Answer 18

the formation of a clot
- in the intrinsic pathway, coagulation factors lead to activation of factor 10
- in the extrinsic factor phospholipids and ca2+ are released
- factor 10 uses Ca2+ and the phosolipids to set of Active 10
- in the Common Pathway, Active 10 and Ca2+ turns prothrombin into thrombin
- Thrombin turns Fibrinogen into Fibrin and factor 13 into Active 13
- Active 13 and Ca2+ turns fibrin into cross linked fibrin

Question 19

Explain Fibrinolysis

Answer 19

Once tissue is repaired, clot is dissolved by enzyme plasmin

Question 20

Blood Type O

Answer 20

• has no antigens
• creates antibodies A and B

Question 21

Blood Type A

Answer 21

• has antigen A
• makes antibodies B

Question 22

Blood Type B

Answer 22

• has antigen B
• makes antibodies A

Question 23

Blood Type AB

Answer 23

• has both antigens
• makes no antibodies

Question 24

Why does blood typing occur?

Answer 24

if you make antibodies, you cant have blood with that antigen or your blood will clot

Question 25

What makes the rhesus factor different?

Answer 25

Rh- people don’t make the rhesus factor unless they are exposed to Rh+

Question 26

What’s the danger to new Rh- mothers

Answer 26

if the baby is Rh+, the mother will make antibodies for the Rh+ if their blood mixes. The second baby could then be affected?

Question 27

What’s the solution to the Rh baby issue

Answer 27

inject with immune repressors so the mom won’t make the antibodies