mc Flashcards
For active expiration, which occurs first?
A. air flows out of the lungs
B. thoracic volume decreases
C. alveolar pressure becomes greater than atmospheric
D. expiratory muscles contract
d.expiratory muscles contract
At rest, what is the normal carbon dioxide partial pressure (Pco2) in the pulmonary artery of a healthy
person?
A. 40 mm Hg
B. 46 mm Hg
C. 100 mm Hg
D. 150 mm Hg
B. 46 mm Hg
Which value is about the same in both the pulmonary and systemic circulations?
A. total blood flow per minute
B. vascular resistance
C. arterial pressure
a. total blood flow per minute
Which part of the brain is most important in determining the respiratory pattern for a person that is doing spirometric measurements like a forced vital capacity?
A. cerebral cortex
B. subcortical regions
C. medulla oblongata
D. pons
a. cerebral cortex
Expiration of alveolar gas:
A. is typically active.
B. can follow contraction of the expiratory muscles.
C. occurs when alveolar pressure is less than atmospheric pressure.
D. occurs as the lung volume increases.
B. can follow contraction of the expiratory muscles
Loretta breathes 10 times per minute; her tidal volume is 600 ml and her anatomic dead space is 300
ml. What is her alveolar ventilation?
A. 6000 ml/min
B. 4000 ml/min
C. 3000 ml/min
D. 2000 ml/min
C. 3000 ml/min
The volume of air inhaled between the FRC (functional residual capacity) and a maximal inspiration is the:
A. inspiratory capacity
B. tidal volume
C. inspiratory reserve volume
D. residual volume
a. inspiratory capacity
Emphysema, a pulmonary blood clot, and lung cancer are all likely to:
A. increase the lung compliance.
B. decrease the work of breathing.
C. decrease the surface area for gas exchange.
D. increase the PAO2 in the alveolar gas
d. decrease the surface area for gas exchange
Hemoglobin in systemic arterial blood is usually described as:
A. fully saturated with oxygen.
B. deoxyhemoglobin
C. 2,3 - BPG
D. having 2 alpha- and 2 gamma- chains
a. fully saturated with oxygen
The oxygen-hemoglobin dissociation curve:
A. has an steep portion that facilitates O2 unloading in the lungs
B. has a plateau portion that facilitates O2 loading in the lungs
C. has a vertical axis (Y axis) that depicts the Partial pressure of oxygen
D. is linear (a straight line) because of the interaction of the 4 heme centers.
b. has a plateau portion that facilitates o2 loading in the lungs
The oxygen-hemoglobin dissociation curve is shifted rightward by increasing which property in the blood?
A. 2,3-DPG (BPG) content
B. PO2
C. hematocrit
D. pH
a. 2,3-BPG content
The majority (70%) of CO2 in blood is transported in what form?
A. carbaminohemoglobin
B. dissolved CO2
C. H2CO3
D. HCO3-
d. HCO3-
When a patient secretes large amounts of mucus into the airways, you would expect the mucus to
__________ the lumen of the conducting zone, ______ the resistance to airflow, and _____the volume of
the dead space.
A. enlarge; decrease; increase
B. narrow; decrease; increase
C. enlarge; increase; decrease
D. narrow; increase; decrease
D. narrow; increase; decrease
Which aspect of blood chemistry elicits the greatest increase in activity of the peripheral
chemoreceptors?
A. systemic arterial pH of 7.4
B. oxyhemoglobin saturation of 90%
C. venous PCO2 of 46 mmHg
D. arterial Po2 less than 60 mmHg
arterial Po2 less than 60mmHg
When one visits a region at high altitudes (e.g., the Peruvian Andes), what is the primary sensed
variable that leads to an increase in one’s minute ventilation?
A. systemic arterial PO2
B. systemic arterial PCO2
C. systemic venous pH
D. CSF pH
a. systemic arterial PO2
What causes the partial lung collapse in a person that has pneumonia?
A. lung volume increases
B. transpulmonary pressure decreases
C. intrapleural pressure in the affected region becomes more negative
b. transpulmonary pressure decreases
Which cell type is most likely to be abnormal in a prematurely born infant?
A. alveolar type I cells
B. alveolar type II cells
C. alveolar macrophages
D. white blood cells
b. alveolar type II cells
Which brain region is most important in altering your breathing while watching a basketball game?
A. medulla oblongata
B. cerebral cortex
C. pons
D. subcortical regions
d. subcortical regions
Gas exchange across your lungs may be reduced by:
A. increased surface area
B. congestive heart failure
C. decreased dead space
D. all of the above
b. CHF
Pulmonary surfactant:
A. increases lung compliance
B. increases surface tension
C. is more effective as alveolar radius increases
D. is secreted by alveolar type I cells
a. inc lung compliance
The pressure difference between the pressures in the atmosphere and in the alveoli is equal to:
A. pressure divided by flow
B. flow times resistance
C. volume times pressure
b. FLOW x RESISTANCE
What is the total body water weight in a 100-pound female?
20 pounds
40 pounds
60 pounds
80 pounds
60 lbs
An increase in ________ activity causes contraction of the detrusor (bladder) muscle.
sympathetic
parasympathetic
somatic motor
parasympathetic
Relaxation of this muscle in the urinary system is under voluntary control.
A. smooth muscle of the ureters
B. smooth muscle of the urethra
C. internal urethral sphincter
D. external urethral sphincter
E. detrusor muscle
d. external urethral sphincter