Unit 4A Answers (improved)
1) The heart circulates oxygenated blood to the systemic arteries via the aorta but this does
not include the blood which supplies the lungs. The heart supplies the lungs via the pulmonary
arteries, which deliver deoxygenated blood to the lungs to release Carbon Dioxide (CO2) and
pick up oxygen (O2). This oxygen-rich blood goes back to the heart via the pulmonary veins.4A 1
2) Blood circulates away from the heart via arteries, which carry blood away from the heart.
This blood can be deoxygenated at times and also oxygen-rich at other times. The main point is
that arteries carries blood away from the heart. 4A 1
3) Blood circulates back to the heart via veins, which brings blood back to the heart. This blood
can be oxygen-rich at times and also deoxygenated at other times. The main point is that veins
bring blood back to the heart.
4) Oxygen-rich blood which can be found in systemic arteries and pulmonary veins is more of a
scarlet red due to the high oxygen content. While deoxygenated blood found in systemic veins
and pulmonary arteries is more of a burgundy red due to low oxygen content. 4 A 1
5) In the illustrations of systemic circulatory vessels, arteries and arterioles are colored red
indicating their high oxygen content of the blood. The capillary networks are colored red to
purple to blue indicating the loss of their oxygen content and increasing Carbon Dioxide contend
as they facilitate gas exchange. The veins and venules are colored blue in the systemic
circulatory illustrations due to their low oxygen and high carbon dioxide content. But in actuality
the blood within these vessels is always red. 4A 1
6) In the illustrations of the pulmonary circulatory system the pulmonary arteries are colored
blue as they carry deoxygenated blood away from the heart to the lungs where the capillary
network is illustrated first being blue then purple then red due to the gas exchange they
facilitate as the capillaries first get rid of the carbon dioxide and take in oxygen and bring this
oxygen-rich blood back to the heart in pulmonary veins which are colored red. But in actuality
the blood within these vessels are always red. 4A 1
7) The main thing to remember is that arteries and arterioles carry blood away from the heart,
it does not matter what type of oxyhemoglobin is inside of them. And veins and venules carry
blood back to the heart and it does not matter what type of oxyhemoglobin is inside of them
either. 4A 1
8) The extracellular fluids include blood plasma which has more protein than lymph or
interstitial fluids which are fluids found between red blood cells, white blood cells and platelets
that are suspended in plasma. The protein in blood plasma helps pull fluids back into the blood.4A
1
9) The functions of blood are: transportation of blood gases, oxygen and carbon dioxide, along
with nutrients, vitamins, hormones and metabolic waste products, along with regulation of blood
pH acting as buffers, also regulation of temperature by blood flow through the skin and
regulation of osmatic pressure which regulates water movement in the blood and interstitial
fluid, and finally protection by clotting, phagocytes, antibodies and complement. 4A 1
10) Blood is 8% of body weight and the average volume is 5 to 6 liters in males and 4 to 5 liters
in females so an average of about 5 liters. Blood is 55% plasma and 45% formed elements which
are blood cells of which platelets are fragments of cells. 4A 2
11) Then blood is drawn out of a vein into a tube that contains an anticoagulant, which prevents
the blood from clotting, the blood can be centrifuged which will separate the blood into plasma
(55%) and formed elements (45%) which will be made up of Red Blood Cells (RBC) and a buffy
coat which contains White Blood Cells (WBC) and platelets. 4A 2
12) Blood will clot when there is no anticoagulant present and this produces serum and the blood
clot. The red blood cells form the clot by using the protein that was present in the plasma, so
the serum has fewer proteins than plasma. 4A 2
13) Blood plasma is 91.5% water, 7% protein and 1.5% other solutes.
The proteins consist of:
60% albumin which functions to control osmatic pressure and transport steroid hormones which
are made by liver cells,
36% globulins which are made up of gamma globulins that are immunoglobulins, also referred to
as antibodies, which are made by plasma cells (white blood cells), and Alpha and beta globulins
that transport fat-soluble vitamins, which are made by liver cells.
4% clotting proteins, made up of fibrinogen which is the major clotting factor made in the liver
and these clotting proteins are not left in the serum.
The other solutes are made up of electrolytes which are sodium (Na+) potassium (K+) and
Chloride (CL–), along with nutrients and gases such as oxygen (O2), carbon dioxide (CO2), and
nitrogen (N2) (which has no function but diffuses in with the O2.) And finally regulatory
substances such as hormones as well as metabolic wastes . 4A2