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What are the three main components of the circulatory system?
Heart, blood vessels, and blood
Name the three formed elements of blood.
Red blood cells (erythrocytes)
White blood cells (leukocytes)
Platelets
What is the main function of red blood cells?
Transport oxygen and carbon dioxide
What is the average lifespan of a red blood cell?
120 days
What condition results from low red blood cell levels?
Anemia
What are the three major functions of blood?
Transport, protection, and regulation
What is the buffy coat made of?
White blood cells and platelets
What is the shape of a red blood cell?
Biconcave disc
Where are red blood cells produced?
Red bone marrow
What condition occurs when there are too many red blood cells?
Polycythemia
Give three examples of substances transported by blood.
Oxygen
Carbon dioxide
Nutrients
Hormones
Metabolic wastes
Heat
About what percentage of blood is plasma?
About 55%
Do mature red blood cells contain a nucleus?
No (they are anucleate)
What hormone stimulates red blood cell production?
Erythropoietin (EPO)
What is the main function of white blood cells?
Fight infections and provide immune defense
Blood is classified as what type of tissue?
Connective tissue
Approximately what percentage of plasma is water?
About 90%
What protein in red blood cells carries oxygen?
Hemoglobin
Which organ produces this hormone?
Kidneys
Which white blood cell is most abundant and fights bacterial infections?
Neutrophils
What are the two main parts of blood?
Plasma and formed elements
What is the difference between plasma and serum?
Serum is plasma without clotting proteins
How many oxygen molecules can one hemoglobin molecule bind?
4 oxygen molecules
What does hematocrit measure?
The percentage of blood made up of red blood cells
Which white blood cells produce antibodies?
B lymphocytes