L1 Blood and Its Composition

Question 1

composition of the blood?

Answer 1

contains the blood cells: erythrocytes, leukocytes and thrombocytes
and the fluid portion—–> plasma which have organic and inorganic constituents

Question 2

what is the normal volume of the blood?

Answer 2

5 liters and 55% of it is plasma.

Question 3

what are the 3 functions of the blood?

Answer 3

1) Respiratory function: RBCs transport oxygen and carbon dioxide
2) defensive function: WBCs defend the body against foreign microorganisms
3) haematostatic function: platelets responsible for the stoppage of bleeding
4) other: transports-nutrition-storage-regulating body temperature and excretion.

Question 4

what are the constituents of plasma?

Answer 4

90% water
1% inorganic constituents: sodium chloride calcium potassium
9% organic constituents: 7% plasma proteins 2%nutrients and waste products

Question 5

What are plasma proteins?

Answer 5

their concentration is about 7-9 grams per decilitre and contain 3 major proteins
albumin-4.8g/dl
globulin-2.7g/dl
fibrinogen-0.2g/dl

Question 6

what’s the albumin level in normal adult’s plasma? what’s the total exchangeable pool? and where is it stored?

Answer 6

3.5-5.0g/dl and the total exchangeable pool is 4.0 to 5.0g/kg body mass
38-45% of it is stored in intravuscular and the rest of it is in the skin

Question 7

what’s the % of albumin degraded daily?

Answer 7

6-10% is degraded daily and is being replaced by the liver that produces 200-400mg/kg/d

Question 8

when does albumin decrease and when does it increase?

Answer 8

decreases—> when fasting

increases—-> nephrosis due to excessive albumin loss.

Question 9

state the 7 functions of plasma proteins

Answer 9

1-protein metabolism 
2-regulating the blood volume 
3-Immunity
4-blood coagulation 
5-buffering action
6-regulation of arterial pressure
7-Transport of important substances

Question 10

Protein metabolism?

Answer 10

plasma proteins are constantly used by tissue for their protein metabolism
thus they are dynamic

Question 11

Regulation of blood volume

Answer 11

major function of albumin is providing colloidal osmotic pressure which prevents plasma proteins loss from the capillaries. the capillary walls are relatively impermeable to plasma proteins thus this osmotic pressure tend to pull water back in the blood therefore maintains the blood’s volume

Question 12

Blood coagulation?

Answer 12

some plasma proteins are needed for blood coagulation (clotting factors) especially prothrombin and fibrinogen.
Fibrinogen polymerizes into long threads of fibrin which forms a clot and helps repair the leaks in the circulatory system.

Question 13

Difference between serum and blood?

Answer 13

serum have the same constituents as the plasma but its missing
fibrinogen clotting factors II ,V, VII and it has high levels of serotonin due to the breakdown of platelets during clotting

Question 14

Buffering action?

Answer 14

Plasma proteins are responsible for 15% of the blood’s buffering capacity because the weak ionization of their substituent COOH and NH2 groups.
At normal PH of 7.40 the proteins are anionic.

Question 15

Regulation of arterial blood pressure?

Answer 15

blood is 5 times and plasma is 2 times more viscous than water. viscosity is due to the blood cells and plasma proteins. blood viscosity is partially responsible for their peripheral resistance, which is resistance the blood meets during its passage through peripheral narrow blood vessels. it prevents rapid outflow of the blood thus maintains the normal arterial pressure

Question 16

Transport of important substances?

Answer 16

some plasma proteins are carriers for various hormones other solutes and drugs