BIO 253 EXAM 3 CERTIFICATION EVALUATION
EXAMS 2026 COMPLETE QUESTIONS AND
ANSWERS GUARANTEED TO PASS
◉ hemoglobin saturation.
Answer: percent of hemoglobin that has O2 or any other gas bound
to its iron moiety regardless of the red cell concentration
(hematocrit) in the blood
◉ effect of decreased hematocrit.
Answer: hemoglobin can be 100% saturated with o2 but the oxygen-
carrying capacity of the blood will be decreased
◉ factors that influence hemoglobin saturation.
Answer: 1. PCO2
2. Temperature (increase = decreased affinity for oxygen, curve to
right)
3. H+ Concentration (increase = decreased affinity for oxygen, curve
to right))
4. DPG/ BPG concentration (increase = decreased affinity for
oxygen)
5. presence of hemoglobin found in fetal blood
,◉ fetal hemoglobin.
Answer: has a higher affinity for oxygen than adult hemoglobin
allows adequate oxygen uptake in the placenta to supply the
developing fetus
◉ Carbon Monoxide (CO).
Answer: A colorless, odorless gas that is produced in small
quantities by certain cells of the body and is believed to have
physiologically important functions
toxic at higher concentration; product of incomplete combustion of
hydrocarbons
extremely high affinity for oxygen binding sites in hemoglobin;
reduces amount of O2 that combines with hemoglobin in pulmonary
capillaries
◉ carbaminohemoglobin.
Answer: formed when 25% to 30% of CO2 molecules react
reversibly with the amino groups of hemoglobin
◉ carbonic anhydrase.
,Answer: enzyme that catalyzes the reaction between carbon dioxide
and water to form carbonic acid
present in erythrocytes but not in plasma
◉ total-blood carbon dioxide.
Answer: sum total of dissolved carbon dioxide, HCO3-, and carbon
dioxide in carbaminohemoglobin
◉ respiratory acidosis.
Answer: increased arterial H+ concentration due to carbon dioxide
retention
◉ respiratory alkalosis.
Answer: hyperventilation decreases arterial Pco2 and H+
concentration
◉ breathing depends entirely upon.
Answer: cyclical respiratory muscle excitation of the diaphragm and
the intercostal muscles by their motor neurons
destruction of these neurons or a disconnection between their
origin in the brainstem and respiratory muscles results in paralysis
of the respiratory muscles and death
, ◉ medullary respiratory center.
Answer: part of the medulla oblongata involved in the neural control
of rhythmic breathing
◉ two main components of medullary respiratory center.
Answer: 1. dorsal respiratory group (DRG): fire during inspiration
and have input to the spinal motor neurons that activate the
diaphragm and inspiratory intercostal muscles
2. ventral respiratory group (VRG): contains expiratory neurons that
are important when large increase in ventilation are required
(exercise)
◉ respiratory rhythm generator.
Answer: located in the pre-botzinger complex of neurons in the
upper part of the VRG
composed of pacemaker cells and a neural network that sets the
basal respiratory rate
◉ During active expiration.
Answer: motor neurons activated by the expiratory output from the
VRG cause the expiratory muscles to contract
EXAMS 2026 COMPLETE QUESTIONS AND
ANSWERS GUARANTEED TO PASS
◉ hemoglobin saturation.
Answer: percent of hemoglobin that has O2 or any other gas bound
to its iron moiety regardless of the red cell concentration
(hematocrit) in the blood
◉ effect of decreased hematocrit.
Answer: hemoglobin can be 100% saturated with o2 but the oxygen-
carrying capacity of the blood will be decreased
◉ factors that influence hemoglobin saturation.
Answer: 1. PCO2
2. Temperature (increase = decreased affinity for oxygen, curve to
right)
3. H+ Concentration (increase = decreased affinity for oxygen, curve
to right))
4. DPG/ BPG concentration (increase = decreased affinity for
oxygen)
5. presence of hemoglobin found in fetal blood
,◉ fetal hemoglobin.
Answer: has a higher affinity for oxygen than adult hemoglobin
allows adequate oxygen uptake in the placenta to supply the
developing fetus
◉ Carbon Monoxide (CO).
Answer: A colorless, odorless gas that is produced in small
quantities by certain cells of the body and is believed to have
physiologically important functions
toxic at higher concentration; product of incomplete combustion of
hydrocarbons
extremely high affinity for oxygen binding sites in hemoglobin;
reduces amount of O2 that combines with hemoglobin in pulmonary
capillaries
◉ carbaminohemoglobin.
Answer: formed when 25% to 30% of CO2 molecules react
reversibly with the amino groups of hemoglobin
◉ carbonic anhydrase.
,Answer: enzyme that catalyzes the reaction between carbon dioxide
and water to form carbonic acid
present in erythrocytes but not in plasma
◉ total-blood carbon dioxide.
Answer: sum total of dissolved carbon dioxide, HCO3-, and carbon
dioxide in carbaminohemoglobin
◉ respiratory acidosis.
Answer: increased arterial H+ concentration due to carbon dioxide
retention
◉ respiratory alkalosis.
Answer: hyperventilation decreases arterial Pco2 and H+
concentration
◉ breathing depends entirely upon.
Answer: cyclical respiratory muscle excitation of the diaphragm and
the intercostal muscles by their motor neurons
destruction of these neurons or a disconnection between their
origin in the brainstem and respiratory muscles results in paralysis
of the respiratory muscles and death
, ◉ medullary respiratory center.
Answer: part of the medulla oblongata involved in the neural control
of rhythmic breathing
◉ two main components of medullary respiratory center.
Answer: 1. dorsal respiratory group (DRG): fire during inspiration
and have input to the spinal motor neurons that activate the
diaphragm and inspiratory intercostal muscles
2. ventral respiratory group (VRG): contains expiratory neurons that
are important when large increase in ventilation are required
(exercise)
◉ respiratory rhythm generator.
Answer: located in the pre-botzinger complex of neurons in the
upper part of the VRG
composed of pacemaker cells and a neural network that sets the
basal respiratory rate
◉ During active expiration.
Answer: motor neurons activated by the expiratory output from the
VRG cause the expiratory muscles to contract
