BIOL 235 FINAL EXAM 2025-2026
QUESTIONS AND CORRECT ANSWERS
Exhalation is - ANSWER>>a passive process resulting from elastic recoil of the chest
wall and lungs
Elastic recoil two factors - ANSWER>>recoil of elastic fibers that were stretched during
inhalation, inward pull of surface tension due to the film of alveolar fluid
Exhalation starts - ANSWER>>when inspiratory muscles relax
Lung capacities are - ANSWER>>combination of various lung volumes
Tidal volume - ANSWER>>volume of one breath
Inspiratory reserve volume - ANSWER>>by taking in a very deep breath
Residual volume - ANSWER>>volume left in lungs after forced expiration
Inspiratory capacity - ANSWER>>sum of tidal volume and inspiratory reserve
Functional residual capacity - ANSWER>>sum of residual volume and expiratory
reserve volume
Vital capacity - ANSWER>>sum of inspiratory reserve volume, tidal volume, and
expiratory reserve volume
Total lung capacity - ANSWER>>sum of vital capacity and residual volume
Dalton's law - ANSWER>>each gas in a mixture of gases exerts its own pressure as if
no other gases were present
Henry's law - ANSWER>>the quantity of a gas that will dissolve in a liquid is
proportional to the partial pressure of the gas and its solubility
Gases diffuse - ANSWER>>from areas of higher partial pressure to areas of lower
partial pressure
Rate if pulmonary and systemic gas exchange depend on - ANSWER>>partial pressure
difference of the gases, surface area available for gas exchange, diffusion distance,
molecular weight and solubility of the gases
Most O2 is transported - ANSWER>>by hemoglobin as oxyhemoglobin within red blood
cells
,Most CO2 is transported - ANSWER>>in blood plasma as bicarbonate ions
Most important factor that determines how much O2 binds to hemoglobin -
ANSWER>>the partial pressure of 02, the higher the partial pressure of O2 the more O2
combines with Hb
Other factors affecting the affinity of hemoglobin for oxygen - ANSWER>>acidity, partial
pressure of CO2, temperature
Acidity and O2 affinity for Hb - ANSWER>>as pH decreases or partial pressure of CO2
increases, the affinity of Hb of O2 declines so less O2 combines with hemoglobin and
more is available to tissues
As partial pressure of CO2 increases - ANSWER>>shifts the curve to the right, more
dissociation of O2
As temperature increases - ANSWER>>the affinity of hemoglobin for O2 decreases
Hemoglobin in red blood cells - ANSWER>>transports O2, CO2, and H+
Respiratory center is composed of - ANSWER>>neurons in the medullary respiratory
center in the medulla plus the pontine respiratory group in the pons
Medullary respiratory center - ANSWER>>made up of two collections of neurons called
the dorsal respiratory group and the ventral respiratory group
Dorsal respiratory group - ANSWER>>inhalation, phrenic nerves and intercostal nerves
Ventral respiratory group - ANSWER>>exhalation, becomes activated when forceful
breathing is required
During normal quiet breathing - ANSWER>>the ventral respiratory group is inactive
respiratory group
Chemoreceptors - ANSWER>>two locations in the respiratory system that provide input
During forceful breathing - ANSWER>>the dorsal respiratory group activates the ventral
to the respiratory center
Central chemoreceptors - ANSWER>>located in or near the medulla oblongata respond
to changes in H+ or partial pressure of CO2 in cerebrospinal fluid
, Peripheral chemoreceptors - ANSWER>>located in aortic and carotid bodies, sensitive
to changes in the blood
Increase in arterial blood CO2 - ANSWER>>stimulates the dorsal respiratory group
As cardiac output rises - ANSWER>>blood flow to the lungs (pulmonary perfusion)
increases
O2 diffusion capacity - ANSWER>>can increase during exercise because more
pulmonary capillaries become maximally perfused
Abrupt increase in breathing at the start of exercise is due to - ANSWER>>neural
changes that send excitatory impulses to the dorsal group of the medullary respiratory
center of the medulla
More gradual increase in breathing during moderate exercise - ANSWER>>due to
chemical and physical changes in the blood stream
During strenuous exercise - ANSWER>>bicarbonate buffers H+ released by lactic acid
which liberates CO2, which further increases partial pressure of CO2
Organs of the GI tract - ANSWER>>mouth, pharynx, esophagus, stomach, small
intestine, large intestine
Accessory digestive organs - ANSWER>>teeth, tongue, salivary glands, liver,
gallbladder, pancreas
Functions of the digestive system - ANSWER>>ingestion, secretion, mixing and
propulsion, digestion, absorption, defecation
Functions of the digestive system acronym - ANSWER>>I see mom and pop digging a
ditch
Ingestion - ANSWER>>taking food into mouth
Secretion - ANSWER>>release of water, acid buffers, and enzymes into the lumen of GI
tract
Mixing and Propulsion - ANSWER>>churning and movement of food through GI tract
Digestion - ANSWER>>mechanical breakdown of food
Absorption - ANSWER>>passage of digested products from GI tract into blood and
lymph
QUESTIONS AND CORRECT ANSWERS
Exhalation is - ANSWER>>a passive process resulting from elastic recoil of the chest
wall and lungs
Elastic recoil two factors - ANSWER>>recoil of elastic fibers that were stretched during
inhalation, inward pull of surface tension due to the film of alveolar fluid
Exhalation starts - ANSWER>>when inspiratory muscles relax
Lung capacities are - ANSWER>>combination of various lung volumes
Tidal volume - ANSWER>>volume of one breath
Inspiratory reserve volume - ANSWER>>by taking in a very deep breath
Residual volume - ANSWER>>volume left in lungs after forced expiration
Inspiratory capacity - ANSWER>>sum of tidal volume and inspiratory reserve
Functional residual capacity - ANSWER>>sum of residual volume and expiratory
reserve volume
Vital capacity - ANSWER>>sum of inspiratory reserve volume, tidal volume, and
expiratory reserve volume
Total lung capacity - ANSWER>>sum of vital capacity and residual volume
Dalton's law - ANSWER>>each gas in a mixture of gases exerts its own pressure as if
no other gases were present
Henry's law - ANSWER>>the quantity of a gas that will dissolve in a liquid is
proportional to the partial pressure of the gas and its solubility
Gases diffuse - ANSWER>>from areas of higher partial pressure to areas of lower
partial pressure
Rate if pulmonary and systemic gas exchange depend on - ANSWER>>partial pressure
difference of the gases, surface area available for gas exchange, diffusion distance,
molecular weight and solubility of the gases
Most O2 is transported - ANSWER>>by hemoglobin as oxyhemoglobin within red blood
cells
,Most CO2 is transported - ANSWER>>in blood plasma as bicarbonate ions
Most important factor that determines how much O2 binds to hemoglobin -
ANSWER>>the partial pressure of 02, the higher the partial pressure of O2 the more O2
combines with Hb
Other factors affecting the affinity of hemoglobin for oxygen - ANSWER>>acidity, partial
pressure of CO2, temperature
Acidity and O2 affinity for Hb - ANSWER>>as pH decreases or partial pressure of CO2
increases, the affinity of Hb of O2 declines so less O2 combines with hemoglobin and
more is available to tissues
As partial pressure of CO2 increases - ANSWER>>shifts the curve to the right, more
dissociation of O2
As temperature increases - ANSWER>>the affinity of hemoglobin for O2 decreases
Hemoglobin in red blood cells - ANSWER>>transports O2, CO2, and H+
Respiratory center is composed of - ANSWER>>neurons in the medullary respiratory
center in the medulla plus the pontine respiratory group in the pons
Medullary respiratory center - ANSWER>>made up of two collections of neurons called
the dorsal respiratory group and the ventral respiratory group
Dorsal respiratory group - ANSWER>>inhalation, phrenic nerves and intercostal nerves
Ventral respiratory group - ANSWER>>exhalation, becomes activated when forceful
breathing is required
During normal quiet breathing - ANSWER>>the ventral respiratory group is inactive
respiratory group
Chemoreceptors - ANSWER>>two locations in the respiratory system that provide input
During forceful breathing - ANSWER>>the dorsal respiratory group activates the ventral
to the respiratory center
Central chemoreceptors - ANSWER>>located in or near the medulla oblongata respond
to changes in H+ or partial pressure of CO2 in cerebrospinal fluid
, Peripheral chemoreceptors - ANSWER>>located in aortic and carotid bodies, sensitive
to changes in the blood
Increase in arterial blood CO2 - ANSWER>>stimulates the dorsal respiratory group
As cardiac output rises - ANSWER>>blood flow to the lungs (pulmonary perfusion)
increases
O2 diffusion capacity - ANSWER>>can increase during exercise because more
pulmonary capillaries become maximally perfused
Abrupt increase in breathing at the start of exercise is due to - ANSWER>>neural
changes that send excitatory impulses to the dorsal group of the medullary respiratory
center of the medulla
More gradual increase in breathing during moderate exercise - ANSWER>>due to
chemical and physical changes in the blood stream
During strenuous exercise - ANSWER>>bicarbonate buffers H+ released by lactic acid
which liberates CO2, which further increases partial pressure of CO2
Organs of the GI tract - ANSWER>>mouth, pharynx, esophagus, stomach, small
intestine, large intestine
Accessory digestive organs - ANSWER>>teeth, tongue, salivary glands, liver,
gallbladder, pancreas
Functions of the digestive system - ANSWER>>ingestion, secretion, mixing and
propulsion, digestion, absorption, defecation
Functions of the digestive system acronym - ANSWER>>I see mom and pop digging a
ditch
Ingestion - ANSWER>>taking food into mouth
Secretion - ANSWER>>release of water, acid buffers, and enzymes into the lumen of GI
tract
Mixing and Propulsion - ANSWER>>churning and movement of food through GI tract
Digestion - ANSWER>>mechanical breakdown of food
Absorption - ANSWER>>passage of digested products from GI tract into blood and
lymph