HPEX375 exam 3
Which of the following is the primary way that CO2 formed in the tissue is transported to the lungs?
as bicarbonate
respiratory zone
respiratory bronchioles and alveoli
What is the shape of the oxyhemoglobin dissociation curve?
sigmoidal
Which of the following contributes to an increase in venous return during exercise?
skeletal muscle pump, respiratory pump, and venoconstriction
What factors determine resistance to blood flow?
blood viscosity, vessel length, vessel radius
What are the responses of cardiac output to incremental exercise?
cardiac output increases
What are the muscles of inspiration?
diaphragm and external intercostals
How is CO2 transported in the blood?
dissolve gas -> bicarbonate -> carbaminohemoglobin bound to hemoglobin
Where is nitric oxide produced?
endothelium or arterioles
What are the responses of heart rate to incremental exercise?
first cardiac output increases to meet
What is the utility of the double product?
good estimate of myocardial oxygen consumption
What role does the nitric oxide play in blood flow regulation?
increases muscle blood flow
How does the cardiovascular system aid in the regulation of body temperature?
increasing the amount of speed of blood flowing to and within the skin by widening the blood vessels (vasodilation) allows more heat to be lost thereby reducing body temperature
What is the ventilatory threshold?
infection point where VE increases exponentially
What are the muscles of expiration?
internal intercostals and abdominal muscles
Vessels that carry blood away from the heart are called
Arteries
What are the responses of stroke volume to incremental exercise?
stroke volume increases by about 20-50% in the transition from rest to submaximal exercise
How would the heart rate and blood pressure responses compare during exercise using arms vs. legs to do the exact same absolute oxygen consumption (L/min)?
it depends on type, intensity, and duration of exercise
Exercise-induced hypoxemia has been shown to occur in ~50% of highly trained males and females. Which of the following is thought to cause the reduction in arterial PO2 in these individuals?
- Ventilation/Perfusion mismatch - Short red blood cell transit time through the pulmonary capillary
Define the term "double product" (AKA rate pressure product).
- increase linearly with exercise intensity - indicates the work of the heart
What are the two major adjustments that must occur in blood flow during exercise?
- increased cardiac output - redistribution of blood flow from inactive organs to active muscle
What volumes are included in the assessment of vital capacity?
- tidal volume - inspiratory reserve volume - expiration volume
Explain the closing mechanisms for each heart valve type.
- tricuspid valve: located between the right atrium and the right ventricle. - pulmonary valve: located between the right ventricle and the pulmonary artery. - mitral valve: located between the left atrium and the left ventricle. - aortic valve: located between the left ventricle and the aorta.
Provide the names and locations of the 4 different heart valves.
- tricuspid valve: located between the right atrium and the right ventricle. - pulmonary valve: located between the right ventricle and the pulmonary artery. - mitral valve: located between the left atrium and the left ventricle. - aortic valve: located between the left ventricle and the aorta.
If the barometric pressure at sea level is 760 mmHg, what is the partial pressure of oxygen at sea level?
159 mmHg
Define vital capacity.
maximum amount of gas that can be expired after a maximum inspiration
What is the significance of the shape of the oxyhemoglobin dissociation curve?
A rightward shift of the curve indicates that hemoglobin has a decreased affinity for oxygen, thus, oxygen actively unloads.
Which of the following are true regarding the pressure changes during the cardiac cycle?
Blood can only leave the left ventricle when the pressure in the left ventricle exceeds the pressure in the aorta.
Which of the following receptors are located in the medulla and are sensitive to changes in PCO2 and H+ in the cerebrospinal fluid?
Central Chemoreceptors
What respiratory system components makes up the conducting zone?
moves air into and out of the lungs
How does atmospheric pressure change during inspiration and expiration?
During inspiration the pressure in the alveoli becomes less than the pressure at the airway opening (i.e., the mouth and nose) and gas flows into the lungs and during expiration it increases the intraalveolar pressure
What volume and pressure changes occur that result in inspiration of air?
During inspiration, the diaphragm contracts and the thoracic cavity increases in volume. It decreases the intraalveolar pressure so that air flows into the lungs.
An increase in aortic pressure will increase stroke volume since the strength of contraction is greater. True or False?
False
During a typical breath at rest, tidal volume is greater than residual volume. True or False?
False
During inspiration the diaphragm relaxes, the ribs are pulled downward, the volume of the lungs decreases, and the intrapulmonary pressure is raised. True or False?
False
The QRS complex on the EKG represents atrial depolarization. True or False?
False
How does intrapleural pressure change during inspiration and expiration?
Intrapleural pressure becomes more subatmospheric or more negative during inspiration and the relaxation of the diaphragm and elastic recoil of tissue decreases the thoracic volume and increases the intraalveolar pressure during expiration.
How does intrapulmonic pressure change during inspiration and expiration?
Intrapulmonary pressure is lowered during inspiration and is raised during expiration
Which of the following layers is the muscular layer of the heart?
Myocardium
What is a typical hematocrit value?
Normal levels of hematocrit for men range from 41% to 50%. Normal level for women is 36% to 48%.
Trace the path of a red blood cell leaving the largest, thickest chamber in the heart and ultimately returning to that same chamber.
Red blood cells pick up oxygen in the lungs. Blood travels away from the heart and lungs through the arteries.
Which of the following IS NOT a component of the conducting zone?
Respiratory Bronchioles
Which of the following is considered the "pacemaker" of the heart?
Sinoatrial Node
conducting zone
nose to terminal bronchioles
What factors are thought to cause the ventilatory threshold during incremental exercise?
The increasing ventilation rate due to faster breathing by an individual to get rid of CO2 during incremental exercise
An increased frequency of nerve impulses down the vagus nerve would release acetylcholine at the SA and AV nodes resulting in a decrease in heart rate. True or False
True
Blood flow (L/min) is directly proportional to the pressure difference between mean arterial pressure and right atrial pressure, but inversely proportional to the resistance to blood flow. True or False
True
Myoglobin's affinity for oxygen is higher than hemoglobin's affinity for oxygen.
True
Resting cardiac output is approximately 5 L/min in untrained males. True or False?
True
Define FEV1.
Volume of air expired during 1 second during maximal expiration
What volume and pressure changes occur that result in expiration of air?
When the lungs exhale, the diaphragm relaxes, and the volume of the thoracic cavity decreases, while the pressure within it increases. As a result, the lungs contract and air is forced out.
What is hematocrit?
percentage of blood composed of cells
Which of the following factors causes a rightward shift in the oxyhemoglobin dissociation curve?
a decrease in pH
What are the responses of a-vO2 difference to incremental exercise?
a-vO2 difference increases
Which of the following are the microscopic air sacs where gas exchange occurs in the lungs?
alveoli
What are the responses of systolic and diastolic blood pressure to incremental exercise?
systolic increases and diastolic remains fairly constant
What respiratory system components makes up the respiratory zone?
that is oxygen and carbon dioxide, in and out of the blood
Define pulmonary ventilation.
the amount of air moved in or out of the lungs per minute
What factor is most important for determining airway resistance?
the diameter of the airway
Which is more important in the functioning cardiovascular system?
the heart
Why does heart rate increase during steady-state exercise in hot, humid environments?
the higher skin blood flow
How is pulmonary ventilation calculated?
tidal volume x ventilation rate
What are the purposes of the cardiovascular system?
to provide adequate circulation of blood through the body
What determines airflow through the respiratory system?
transpulmonary pressure
Define dead-space ventilation.
volume of air remaining in conducting airways
Define alveolar ventilation.
volume of air that reaches the respiratory zone
