BLOOD PT 1 Flashcards
how much of blood makes up our weight
~ 8% of total body weight
Average volume -
Men: 5-6L
Women: 4-5 L
whats the only fluid tissue in body
blood
what does blood maintain and prevent
maintain body temp, normal pH, and fluid volume
prevent blood loss and infection
what are the three components of blood
plasma, Buffy coat, erythrocytes
describe plasma
55% of whole blood; least dense component
describe Buffy coat
leukocytes and platelets; less than 1% of whole blood
describe erthycroytes
45% of whole blood (hematocrit); most dense component
what are the formed elements of blood
Buffy coat and erthycoytes
whats hematocrit
- Fraction of the total column height occupied by RBCs
- Measure of concentration and not total RBC mass
describe how hematocrit changes for newborns throughout development
∼ 55% in newborn, falls to ∼ 35% at 2 mths
- rises to adult values by puberty
what are the three formed elements of blood
1) Erythrocytes (RBCs)
2) Leukocytes (WBCs)
3) Platelets
which section of the formed elements of blood are true cells
only leukocytes
whats the lifespan of the formed elements of blood
just a few days; most do not divide
what do erthycotes (RBCs) look like and what do they lack
Flattened discs with depressed centers; appear lighter in middle than on edges
lack a nucleus or organelles
what does the appearance of lighter in middle than on edges increase
surface area for gas exchange
