Blood is a type of connective tissue.
It consists of:
o A liquid matrix
o Cells and cell fragments
The liquid matrix in blood is called plasma.
The cells and cell fragments are collectively called the formed elements.
2. Plasma
Plasma is the liquid matrix of blood.
It makes up 55% of the total blood volume.
3. Formed Elements
The formed elements are the cells and cell fragments in blood.
They make up 45% of the total blood volume.
4. Total Blood Volume
In the average adult female, total blood volume is 4–5 L.
In the average adult male, total blood volume is 5–6 L.
5. Blood as a Percentage of Body Weight
Blood makes up about 8% of the total weight of the body.
Plasma Overview
Plasma (PLAZ-mah) is the liquid matrix of blood.
It is described as a pale yellow fluid.
Plasma Composition
, Plasma consists of:
o About 91% water
o About 9% other substances
The other substances include:
o Proteins
o Ions
o Nutrients
o Gases
o Waste products
o Regulatory substances
Reference: (L" table 19.1).
Plasma as a Colloid
Plasma is a colloid (KOL-oyd).
A colloid is defined as a liquid containing suspended substances that do not settle
out of solution.
In plasma, most of the suspended substances are plasma proteins.
Plasma Proteins
Plasma proteins make up about 7% of the volume of plasma.
Reference: (L$ figure 19.1).
Plasma proteins can be classified into three groups, based on molecular size and
charge:
1. Albumins
2. Globulins
3. Fibrinogen
Production of Plasma Proteins
Almost all of the plasma proteins are produced by the liver or blood cells.
A notable exception is protein hormones, which are not included in this group.
Production of Formed Elements
Definition of the Process
The process of blood cell production is called:
o Hematopoiesis (hee-MA-toh-poy-EE-sis), or
o Hemopoiesis (HEE-moh-poy-EE-sis).