Cardiovascular Physiology Exam Questions
with correct answers provided
Components of the Cardiovascular System - ✅✅- Heart: supplies the blood entering the
cardiovascular system
- Blood: carries O2 and CO2, nutrients and wastes, immune cells, clotting cells, etc.
- Arteries: deliver blood to organs and tissues
- Veins: deliver blood back to the heart
- Capillaries: key site of gas exchange
Composition of Blood - ✅✅- Formed elements: cells and cell fragments (45%)
- Plasma (55%)
Formed Elements of Blood - ✅✅- Cells: erythrocytes and leukocytes
- Cell fragments: platelets
Hematocrit - ✅✅- Percentage of blood volume occupied by erythrocytes
- Key health indicator
- Typically about 45% in males and 42% in females
Plasma - ✅✅- Liquid part of blood
- Mostly water (more than 90%)
- Includes dissolved substances: plasma proteins, ions (Na+, K+), nutrients (glucose, amino acids), waste
(urea), gases (O2, CO2), and hormones
Plasma Proteins - ✅✅- Account for most of the plasma solutes by weight
- Three classes: albumins, globulins, fibrinogen
Serum - ✅✅- Plasma with fibrinogen and other clotting proteins removed
,Erythrocytes (Red Blood Cells) - ✅✅- Account for more than 99% of blood cells
- Produced inside the red bone marrow; precursor cell is a reticulocyte
- Main function is gas transport
- Contain hemoglobin
Major Function of Erythrocytes - ✅✅- Gas transport: carry oxygen from the lungs to the tissues and
carry carbon dioxide from the tissues to the lungs
Erythropoiesis - ✅✅- Production of erythrocytes
- Occurs in the red bone marrow
- Regulated by the hormone erythropoietin
Erythrocyte Structure - ✅✅- Small: 7um in diameter
- Biconcave disc shape (this increases the surface-area to volume ratio so gas transport can occur
rapidly)
- Simple structure: no nucleus and few organelles including no ribosomes and no mitochondria
Hemodynamics - ✅✅- The relationship between blood pressure, blood flow, and resistance to blood
flow
Why is the cardiovascular system important? - ✅✅- Our bodies are too large and comprised of too
many cells to rely on diffusion as the sole method of substance transportation
- The cardiovascular/circulatory system facilitates the transport of oxygen and nutrient-rich blood to
active cells and transports byproducts of metabolism away from cells
Erythrocyte Life Span - ✅✅- Since they lack nuclei and other organelles, they cannot reproduce or
maintain their structure for very long
- Average life span is ~120 days
- Damaged or dying erythrocytes are destroyed in the spleen and liver
, Substances Required for Erythrocyte Production - ✅✅- Iron
- Folic acid
- Vitamin B12
Hemoglobin - ✅✅- An iron-containing protein in red blood cells that reversibly binds oxygen and
carbon dioxide
Erythropoietin (EPO) - ✅✅- Hormone that controls erythropoiesis
- Secreted into the blood by the cells in the kidney and stimulates the production of erythrocytes in the
bone marrow
- Normally released in small amounts that stimulate the production of erythrocytes at a rate similar to
erythrocyte breakdown
Stimuli For Increased Erythropoietin Secretion - ✅✅- Low blood oxygen and a decrease in oxygen
delivery to the kidneys
- May be caused by insufficient pumping of the heart, lung disease, anemia, prolonged exercise, and/or
exposure to high altitudes
- The increased erythropoietin secretion increases the oxygen-carrying capacity of the blood
Increased Erythropoiesis Loop - ✅✅- Stimulus: decreased oxygen delivery to kidneys
- Increased EPO secretion by kidneys
- Increased plasma erythropoietin
- Increased erythrocyte production in bone marrow
- Increased blood hemoglobin levels and blood oxygen-carrying capacity
- Result: restoration of oxygen-carrying capacity
Type of Circulatory System in Humans - ✅✅- Closed loop
- Contains two circuits: pulmonary and systemic circulation
with correct answers provided
Components of the Cardiovascular System - ✅✅- Heart: supplies the blood entering the
cardiovascular system
- Blood: carries O2 and CO2, nutrients and wastes, immune cells, clotting cells, etc.
- Arteries: deliver blood to organs and tissues
- Veins: deliver blood back to the heart
- Capillaries: key site of gas exchange
Composition of Blood - ✅✅- Formed elements: cells and cell fragments (45%)
- Plasma (55%)
Formed Elements of Blood - ✅✅- Cells: erythrocytes and leukocytes
- Cell fragments: platelets
Hematocrit - ✅✅- Percentage of blood volume occupied by erythrocytes
- Key health indicator
- Typically about 45% in males and 42% in females
Plasma - ✅✅- Liquid part of blood
- Mostly water (more than 90%)
- Includes dissolved substances: plasma proteins, ions (Na+, K+), nutrients (glucose, amino acids), waste
(urea), gases (O2, CO2), and hormones
Plasma Proteins - ✅✅- Account for most of the plasma solutes by weight
- Three classes: albumins, globulins, fibrinogen
Serum - ✅✅- Plasma with fibrinogen and other clotting proteins removed
,Erythrocytes (Red Blood Cells) - ✅✅- Account for more than 99% of blood cells
- Produced inside the red bone marrow; precursor cell is a reticulocyte
- Main function is gas transport
- Contain hemoglobin
Major Function of Erythrocytes - ✅✅- Gas transport: carry oxygen from the lungs to the tissues and
carry carbon dioxide from the tissues to the lungs
Erythropoiesis - ✅✅- Production of erythrocytes
- Occurs in the red bone marrow
- Regulated by the hormone erythropoietin
Erythrocyte Structure - ✅✅- Small: 7um in diameter
- Biconcave disc shape (this increases the surface-area to volume ratio so gas transport can occur
rapidly)
- Simple structure: no nucleus and few organelles including no ribosomes and no mitochondria
Hemodynamics - ✅✅- The relationship between blood pressure, blood flow, and resistance to blood
flow
Why is the cardiovascular system important? - ✅✅- Our bodies are too large and comprised of too
many cells to rely on diffusion as the sole method of substance transportation
- The cardiovascular/circulatory system facilitates the transport of oxygen and nutrient-rich blood to
active cells and transports byproducts of metabolism away from cells
Erythrocyte Life Span - ✅✅- Since they lack nuclei and other organelles, they cannot reproduce or
maintain their structure for very long
- Average life span is ~120 days
- Damaged or dying erythrocytes are destroyed in the spleen and liver
, Substances Required for Erythrocyte Production - ✅✅- Iron
- Folic acid
- Vitamin B12
Hemoglobin - ✅✅- An iron-containing protein in red blood cells that reversibly binds oxygen and
carbon dioxide
Erythropoietin (EPO) - ✅✅- Hormone that controls erythropoiesis
- Secreted into the blood by the cells in the kidney and stimulates the production of erythrocytes in the
bone marrow
- Normally released in small amounts that stimulate the production of erythrocytes at a rate similar to
erythrocyte breakdown
Stimuli For Increased Erythropoietin Secretion - ✅✅- Low blood oxygen and a decrease in oxygen
delivery to the kidneys
- May be caused by insufficient pumping of the heart, lung disease, anemia, prolonged exercise, and/or
exposure to high altitudes
- The increased erythropoietin secretion increases the oxygen-carrying capacity of the blood
Increased Erythropoiesis Loop - ✅✅- Stimulus: decreased oxygen delivery to kidneys
- Increased EPO secretion by kidneys
- Increased plasma erythropoietin
- Increased erythrocyte production in bone marrow
- Increased blood hemoglobin levels and blood oxygen-carrying capacity
- Result: restoration of oxygen-carrying capacity
Type of Circulatory System in Humans - ✅✅- Closed loop
- Contains two circuits: pulmonary and systemic circulation
