fluid connective tissues

what is blood often defined as in histology? why is it referred this way?

it is often described as a special connective tissue, in which the intercellular substance is a fluid. it is referred to as this way because the intercellular substance of blood lacks a fibrous component

where is most of the intercellular proteins of the blood produced?

it is produced by cells in other tissues, primarily the liver, not by the blood cells

how much blood do humans contain?

they contain about 5 liters of blood, accounting for about 7% of body weight

what are some of the functions of blood?

1. transport of O2, nutrients and hormones to the tissue

2. carrying CO2 to the lungs, as well as waste products to the kidneys to be excreted

3. contributes to the regulation of body temperature

4. pH and electrolyte concentrations is maintained through constant exchange of molecules with interstitial fluids

5. helps with immune defense through production of antibodies

6. blood regulation of blood clotting, preventing blood loss

what is blood composed of?

plasma (55%) and formed elements (45%)

what is plasma? what is it composed of?

• plasma is a straw-colored clear liquid which makes 55% of blood. cellular elements and dissolvable substances (solutes) are suspended

• it is approximately 92% water and 8% solids, which is a mix of organic and inorganic substances.

what are the 3 major proteins present in plasma?

1. albumin (4.5 g/dl)

2. globulin (2.5 g/dl)

3. fibrinogen

characteristics and function of albumin

• smallest and most abundant protein in plasma

• maintains colloidal osmotic (oncotic) pressure

• formed in the liver

characteristics and function of globulin

• alpha, beta and gamma

• includes several proteins of different sizes

• involved in transport of hormones, ions, metals and lipids

what are gamma globulins?

they are immunoglobulins (antibodies) that are synthesized by cells of the lymphatic organs and tissues

characteristics and functions of fibrinogen

• produced by the liver

• takes place in hemostasis system

• essential component for blood clotting and prevention of bleeding

what does the plasma also contain?

hormones from various endocrine organs, metabolites, nutrients and several other substances

functions of plasma proteins

1. maintaining osmotic balance

2. buffering pH changes

3. transport of materials through blood (ex: water insoluble hormones)

4. antibodies (gamma globulins, immunoglobulins

5. clotting factors (fibrinogen)

what are the 3 types of formed elements in blood?

1. erythrocytes (RBC)

2. leukocytes (WBC)

3. thrombocytes (platelets)

what is hematocrit?

the result of elements which are separated by centrifugation done in calibrated tubes. it gives an estimate of the volume of the formed elements