Chapter 21: Blood

Describe the layers of a Centrifuged blood sample

Top: Plasma

Middle: Buffy coat (leukocytes/platelets)

Bottom: erythrocytes

What are the functions of blood?

Transportation

• oxygen, co2, nutrients, hormones, waste products, regulation

• regulates many body functions

List of Regulatory Functions of Blood

Regulation of

• temperature

• PH

• Protection

How does blood regulate temperature?

Plasma absorbs and distributes heat throughout the body

• If body needs COOLED, blood vessels in the dermis dilate and dissipate the heat

• If the body needs to conserve HEAT, blood vessels constrict and warm blood is shunted to deeper vessels

What is the normal pH range of blood?

7.35 - 7.45

Acidosis

When the blood pH is BELOW 7.35, depresses the nervous system and can lead to potential coma and death

Akalosis

Blood pH is ABOVE 7.45, hyperexcited nervous system and possible convulsions

How does the blood protect the body?

Leukocytes help guard against infection by mounting an immune response if a pathogen is found, antigens, antibodies: molecules that can bind to antigens until a leukocyte can kill and destroy it, platelets protect against excessive blood loss

What is the most abundant material in plasma?

Water (92%)

Plasma Proteins

1. Albumins

2. Globulins

3. Fibrinogen

4. Regulatory Proteins

Albumins (function)

Regulate water movement b/w blood and interstitital fluid, transport proteins that carry ions, hormones, and lipids

Globulins Function

Bind, support, protect certain water insoluble molecules, hormones, and ions

Fibrinogen Function

Blood clot formation

Regulatory Proteins

Enzymes and proenzymes

What is a hematocrit?

The percentage of the volume of all formed elements in the blood

• % of erythrocytes

% of hematocrit in males/females

Male: 42-56

Female: 38 - 46

High vs Low Hematocrit

High: dehydrated or blood dropping

Low: anemia