Blood and Homeostasis

Question 1

what is plasma made up of?

Answer 1

plasma proteins and interstitial fluid

Question 2

what are the three types of plasma proteins in the blood?

Answer 2

albumin
fibrinogen
globulins

Question 3

what are the components of blood?

Answer 3

plasma, RBC, WBC, platelets

Question 4

what molecule stimulates the production of erythrocytes, and when?

Answer 4

erythropoietin

released by kidney (and liver) when O2 distribution to the kidney is low

Question 5

how long does it take from erythropoietin being activated to RBC being made?

Answer 5

2-3 days

Question 6

what causes the production of white blood cells and when?

Answer 6

cytokines (interleukins and colony stimulating factors)

production stimulated by infection

Question 7

what are the granulomatous leukocytes?

Answer 7

eosinophils
basophils
neutrophils

Question 8

what are the agranulomatous leucocytes?

Answer 8

monocytes

lymphocytes B and T

Question 9

what is the normal amount of blood in the body, and where is it distributed?

Answer 9

5 Liters:
1 in arterial circulation
1 in pulmonary circulation
3 in venous circulation

Question 10

what is the lifespan of a RBC?

Answer 10

120 days

Question 11

what is the lifespan of a platelet?

Answer 11

10 days

Question 12

what stimulates the production of platelets?

Answer 12

thrombopoietin

Question 13

what causes plasma to go yellow when hematocrit is separated?

Answer 13

bilirubin in the blood

Question 14

what is the stickiness of plasma and whole blood vs water?

Answer 14

plasma - 1.8x thicker than water

whole blood - 3 or 4x thicker than water

Question 15

what affects the viscosity of blood?

Answer 15

temperature
blood flow
increased hematocrit production

Question 16

what are the characteristics of negative feedback systems, and what is an example of them?

Answer 16

commonest type of feedback in body
returns levels back to normal
can't prevent change from happening
self-limiting
oscillates around parameters
eg temperature, blood glucose, blood pressure etc

Question 17

what are the characteristics of feed-forward systems, and what is an example of them?

Answer 17

more sophisticated than negative feedback
can prevent large change to a degree
eg goosebumps in reaction to temperature

Question 18

what are the characteristics of positive feedback systems, and what is an example of them?

Answer 18

normally pathological
causes an increase in response
eg oxytocin during labor, action potentials in nerves
eg diabetes

Question 19

which systems are responsible for coordination of homeostasis?

Answer 19

endocrine system

nervous system

Question 20

what percentage of water goes into which compartments?

Answer 20

2/3 - ICF

1/3 - ECF (ISF and plasma)

Question 21

what are the values of water content in different compartments?

Answer 21

plasma - 3L
interstitial fluid - 11L
ICF - 28L

Question 22

what is the total water content in the body?

Answer 22

42L

Question 23

which water compartments in the body can be measured directly?

Answer 23

the ones that include plasma:
plasma
total body water
ECF

Question 24

which water compartments in the body can be measured indirectly?

Answer 24

ISF

ICF

Question 25

what mechanisms are used to measure water compartments directly?

Answer 25

plasma - radioactive dye on plasma proteins
ECF - large molecules that cross capillary but not cell
total body water - loading dose of heavy water

Question 26

what are the three things to bear in mind when considering the dilution principle?

Answer 26

1. concentration = mass/volume
2. only body compartments that include plasma can be measured directly
3. the different types of barriers in the body compartments

Question 27

how to calculate the volume of distribution?

Answer 27

quantity injected/total concentration of sampled fluid