(56. What is the normal pH of blood) 18.1b Physical Characteristics of Blood

Temperature

- 1 degree (or 1C) higher than measured body temperature - Warms area through which it travels

Viscosity

- 4 to 5 times more viscous than water (thicker) - Depends on amount of dissolved substances in blood • e.g., increased if erythrocytes increased • increased if amount of fluid decreases

Volume

- About 5 liters in an adult - Males with slightly more blood than females - Normal blood volume essential for maintaining blood pressure

Color

- The color of blood depends upon whether it is oxygen-rich or oxygen-poor. *Oxygen-rich blood is bright red* or *almost scarlet*. Contrary to popular belief, oxygen-poor blood is not blue; rather, oxygen-poor *blood is dark red.* • appears blue in superficial veins • due to the way blue light reflected back to the eye

Blood

- is a type of connective tissue that can be described based on its physical characteristics including color, volume, viscosity, plasma concentration, temperature, and pH:

Blood pH

- Plasma slightly alkaline (or slightly basic) - pH between 7.35 and 7.45 - And the normal Ph is 7

Plasma concentration

- Relative concentration of solutes in plasma - Determines whether fluids move into or out of plasma by osmosis • e.g., during dehydration plasma hypertonic • fluid moving into plasma from surrounding tissues