A&P II Test I Study Guide
Dr. Bailey
Chapter 18 The Endocrine System
Endocrine cells release their secretions directly into body fluids.
Hormones are chemical messengers that are released in one tissue and transported in the
bloodstream to alter the activities of specific cells in other tissues.
Chapter 19 Blood
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The function of blood is the transport of nutrients and wastes, transport of body heat, transport
of gases, defense against toxins and pathogens
Formed elements make up 45 percent of blood (the remainder of the blood is called plasma).
The combination of plasma and formed elements is called whole blood.
The total volume of blood in the body of a 76-kg man is approximately 5.3 liters.
The most abundant component of plasma is water.
A plasma protein essential for blood coagulation is fibrinogen.
All the circulating red blood cells in an adult originate in the red bone marrow.
Red blood cell production is regulated by the hormone erythropoietin.
Ferritin, hemosiderin, and transferrin are proteins that function to store or transport iron.
In adults, the only site of red blood cell production, and the primary site of white blood cell
formation, is the red bone marrow. In adults, red bone marrow is located in the sternum and
ribs, proximal epiphyses of long bones, iliac crest, body of vertebrae.
Each heme ring in hemoglobin encloses an atom of iron.
Excess iron is stored in the liver and spleen as hemosiderin and ferritin.
More than 95 percent of the protein in a red blood cell is hemoglobin.
The function of hemoglobin is to carry dissolved blood gases.
Anemia is a condition in which the oxygen-carrying capacity of the blood is reduced.
Aged and damaged erythrocytes are broken down by macrophages in the spleen, liver, and
bone marrow.
In adults, process of red blood cell production, erythropoiesis, exclusively takes place in red
bone marrow.
The developmental stage at which erythrocytes enter the circulation is as reticulocytes.
Reticulocytes are immature erythrocytes that are present in the circulation.
Chapter 20- The Heart
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In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus,
esophagus, and trachea called the mediastinum.
The cusps (leaflets) of atrioventricular valves attach directly to chordae tendineae.
The atrioventricular valves are located between atria and ventricle and include the tricuspid
and mitral valves.
The semilunar valves are the pulmonary valve and the aortic valve.
Contractions of the papillary muscles prevent the atrioventricular valves from reversing into the
atria.
The visceral pericardium is the same as the epicardium.
Most of the middle layer in the heart wall is composed of cardiac muscle cells.
The right ventricle pumps blood to the right and left lungs.
The left ventricle pumps blood to the aorta.
**Blood Flow Through the Heart/Circulatory System**
 Oxygen deprived blood from the head, upper extremities, torso, enters through the SVC.
Oxygen deprived blood from the abdomen, lower extremities, enters through the IVC.
 Blood travels from the SVC and IVC into the Right Atrium.
 Right Atrium pass the Tricuspid Valve to the Right Ventricle
 Contraction of the Right Ventricle forces the Pulmonary Valve to open
 Blood flows through the Pulmonary Valve into the Pulmonary Trunk
 Blood is distributed by the right and left Pulmonary Arteries to the Lungs where it unloads
carbon dioxide (CO2) and picks up oxygen (O2).
 Oxygen rich blood returns from the lungs via the Pulmonary Veins to the Left Atrium
 Blood in the Left Atrium flows through the Mitral Valve (bicuspid valve) into the Left
Ventricle
 Contraction of the Left Ventricle forces the Aortic Valve to open
 Blood flows through the Aortic valve into the ascending aorta.
 Blood is distributed to all the organs in the body where it unloads oxygen and loads CO2).
 The cycle then repeats itself.