Composition and Function of Blood

Question 1

Cellular elements

Answer 1

erythrocytes
leukocytes
platelets

Question 2

Plasma

Answer 2

Proteins-immunoglobulins, clotting proteins, lipid escorts
Nutrients
Ions
Wastes
Hormones

Question 3

Blood volume

Answer 3

4-6L, 8% of body weight

Question 4

Hemtocrit

Answer 4

packed cell volume. normal value is 45%

Question 5

Hemoglobin

Answer 5

4 globin chains-each w/ heme group that can carry a molecule of oxygen.
250mill Hb/RB
95% dry weight of cell

Question 6

Spectrin

Answer 6

stretchable protein under plasma membrane in RBc, allows shape distortion

Question 7

glycolytic enzymes

Answer 7

Generate ATP by glycolysis in RBC

Question 8

carbonic anhydrase

Answer 8

in RBC, catalyzes formation of Carbonic acid from CO2 and water

Question 9

RBC lacks

Answer 9

nucleus, organelles, ribosomes

Question 10

Erythropoiesis

Answer 10

formation of erythrocytes, 4 day process-stem to RBC
begins in bone marrow and completed in circulating blood
100 mill/min

Question 11

Erythropoiesis exceeding rate of RBC destruction

Answer 11

conditions of tissue oxygen deficiency which is sensed by kidneys that produce erythropoietin (EPO) that stimulates bone marrow to increase rate of erythrocyte production

Question 12

Erythrocyte destruction

Answer 12

break apart in capillaries b/c of mechanical stress within 3-4 months of formation.
tested in sinuses in spleen and lvier
debris eaten by macrophages in spleen and liver

Question 13

Why is Hb needed to carry O2 in blood

Answer 13

O2 alone has low solubility in blood

Heme alone would carry CO not O2

Question 14

Cooperative

Answer 14

Each O2 molecule that binds makes it easier for the next O2 to bind. results in sigmoidal binding kinetics

Question 15

Hb also binds

Answer 15

CO2- decreases affinity for O2 when CO2 is binded
H+-kicks O2 off Hb
Bisphosphoglycerate (BPG)-more O2 dumped in tissues

Question 16

Bohr effect

Answer 16

pH dependent shift in O2 binding curve of Hb

Question 17

Fetal Hb

Answer 17

2 alpha 2 gamma, higher affinity for O2 than adult Hb

Question 18

Muscle myoglobin

Answer 18

stores O2, related to Hb

Question 19

Diving response

Answer 19

slowed heart rate, vasoconstriction, splemic cnotraction, changing buyancy, less sensitivity to lower blood pH

Question 20

Platelet plugs

Answer 20

form early

Question 21

Fibrin clots

Answer 21

form later

Question 22

Platelets

Answer 22

> 250 000mmcubed, do not respond to smooth vessel walls

activated by collagin fibers, damage to vessel walls, ahterosclerotic plaques

Question 23

Opposing clotting

Answer 23

smooth vessel walls, anticoagulants, Heparon sulfate (Warfarin)

Question 24

Favouring clothing

Answer 24

rough vessel walls, vit-K, sluggish blood flow

Question 25

Clot dissolution

Answer 25

Fibrinolysis

plasminogen->(TPA)-> plasmin->dissolves clots