P3 chapter 23 THE RESPIRATORY SYSTEM Flashcards
Chemoreceptors in the brain are activated primarily by the presence in the cerebrospinal fluid of
a. hydrogen ions
b. oxygen ions
c. carbonic acid
d. bicarbonate ions
a. hydrogen ions
Carbon dioxide binds to the globin portion of hemoglobin to form
a. oxyhemoglobin
b. hemoglobin
c. carbonic anhydrase
d. carbaminohemoglobin
d. carbaminohemoglobin
Mucous membranes of the nasal passages, pharynx and trachea are lined with what type of epithelium?
a. stratified columnar
b. simple squamous
c. pseudostratified ciliated columnar
d. proprioceptors
c. pseudostratified ciliated columnar
The enzyme carbonic anhydrase causes
a. carbon dioxide to react with water
b. carbon dioxide to react with bicarbonate ions
c. hydrogen ions to react with bicarbonate ions
d. hydrogen ions to react with water
a. carbon dioxide to react with water
The term pulmonary ventilation refers to
a. external respiration
b. cellular respiration
c. internal respiration
d. breathing
d. breathing
If the air we breath contains 10 percent of Gas X, the partial pressure of Gas X is
a. 760 mm Hg
b. 76 mm Hg
c. 7.6 mm Hg
d. 0.76 mm Hg
b. 76 mm Hg
Nerves, pulmonary vessels, and bronchi enter the lungs at the
a. cupola
b. hilus
c. base
d. costal surface
b. hilus
As blood enters the systemic capillaries
a. PO2 is high in the blood and low in the tissues
b. PO2 is low in the blood and high in the tissues
c. PCO2 is high in the blood and low in the tissues
d. PCO2 is high in the blood and high in the tissues
b. PO2 is low in the blood and high in the tissues
The first respiratory branches after the trachea are called
a. lobar bronchi
b. segmental bronchi
c. primary bronchi
d. respiratory bronchi
c. primary bronchi
When oxygen combines with heme, what is formed?
a. oxyhemoglobin
b. hemoglobin
c. carbaminohemoglobin
d. carbonic acid
a. oxyhemoglobin
The right lung has
a. 2 fissures and 3 lobes
b. 1 fissure, 2 lobes, and the cardiac notch
c. 2 fissures, 3 lobes, and the cardiac notch
d. 1 fissure and 2 lobes
a. 2 fissures and 3 lobes
Tidal volume is
a. the amount of air that can be forced from the lungs after normal exhalation
b. the volume of air in one breath during normal relaxed breathing
c. about 5,800 mL
d. about 3,000 ml
b. the volume of air in one breath during normal relaxed breathing
During swallowing, the glottis is covered by
a. hyaline cartilage rings
b. the epiglottis
c. pseudostratified ciliated columnar epithelium
d. the tongue
b. the epiglottis
Some hydrogen ions in the blood are produced by the dissociation of
a. bicarbonate
b. carbonic acid
c. carbonic anhydrase
d. carbaminohemoglobin
b. carbonic acid
The amount of oxygen that can combine with heme is determined mainly by the
a. systolic blood pressure
b. partial pressure of oxygen
c. concentration of hydrogen ions
d. concentration of carbonic anhydrase
b. partial pressure of oxygen
During inspiration
a. alveolar pressure decreases
b. the thoracic cavity decreases in size
c. external intercostal muscles pull ribs down and in
d. posterior intercostal muscles contract
a. alveolar pressure decreases
Internal respiration occurs
a. between atmosphere and blood
b. between systemic capillaries and tissue cells
c. in bronchi and trachea
d. in the lungs
b. between systemic capillaries and tissue cells
The amount of oxygen released by the hemoglobin molecules in the blood to the tissues
a. decreases as PCO2 increases
b. increases as blood pH decreases (acidity increases)
c. decreases as temperature increases
d. increases as PCO2 decreases
b. increases as blood pH decreases (acidity increases)
Most carbon dioxide is carried in the blood
a. as part of a bicarbonate ion
b. as carbonic anhydrase
c. as dissolved carbon dioxide gas
d. bound to hemoglobin
a. as part of a bicarbonate ion
The respiratory membrane consists of a.
a single layer of epithelial cells
b. a single layer of epithelial cells and a basement membrane
c. two layers of epithelial cells and 2 basement membranes
d. two layers of epithelial cells
c. two layers of epithelial cells and 2 basement membranes
In the lungs
a. PCO2 is high in the alveoli and low in the capillaries
b. PO2 is low in the alveoli and high in the capillaries
c. PCO2 is low in the alveoli and high in the capillaries
d. PO2 is low in the alveoli and low in the capillaries
c. PCO2 is low in the alveoli and high in the capillaries
Surface tension of the alveolar fluid is reduced by the presence of
a. surfactant
b. serotonin
c. histamine
d. hyaline cartilage rings
a. surfactant
Exchange of respiratory gases occurs in all of the following except the
a. alveolar ducts
b. alveoli
c. respiratory bronchioles
d. terminal bronchioles
d. terminal bronchioles
The phrenic nerves innervate the
a. trachea
b. visceral pleura
c. alveoli
d. diaphragm
d. diaphragm
The vocal cords are found in the a. glottis b. pharynx c. larynx d. trachea
c. larynx
Lung compliance is affected mainly by the amount of elastic tissue in the lungs and the
a. thickness of cartilage in the trachea
b. partial pressure of oxygen in inhaled air
c. diameter of the bronchioles
d. amount of surfactant
d. amount of surfactant
The rhythm of normal breathing is controlled by neurons located in the
a. cerebellum
b. vagus nerve
c. spinal cord
d. medulla oblongata
d. medulla oblongata
Epithelial cells of the respiratory tract are ciliated. The function of the cilia is to
a. trap incoming bacteria and debris
b. secrete mucus
c. move mucus toward the pharynx
d. respond to olfactory stimuli
c. move mucus toward the pharynx
During internal and external respiration, gases move by
a. osmosis
b. active transport
c. endocytosis
d. diffusion
d. diffusion
When the diaphragm lowers during breathing
a. volume in the thoracic cavity increases
b. alveolar pressure increases
c. external intercostal muscles relax
d. pleural cavity decreases in size
a. volume in the thoracic cavity increases
An individual with abnormally large alveoli suffers from
a. emphysema
b. pneumonia
c. pneumothorax
d. pleurisy
a. emphysema
Functionally, the bronchi are considered to be part of the _____ portion of the respiratory system
a. upper
b. lower
c. conducting
d. respiratory
c. conducting
We hold our breath by closing off the opening of the larynx using the
a. ventricular folds (false vocal cords)
b. vocal folds (true vocal cords)
c. epiglottis
d. soft palate
a. ventricular folds (false vocal cords)
Which of the chemical reactions below would NOT be proceeding mainly in the indicated direction as blood flows through a capillary in your triceps muscle?
a. H2 + CO2 H2CO3
b. H+ + HCO3- H2CO3
c. Hb-O2 Hb + O2
d. Hb + CO2 Hb-CO2
b. H+ + HCO3- H2CO3
The most sensitive region of the respiratory tract for triggering the cough reflex is the a. larynx b. epiglottis c. carina d. bronchioles
c. carina
The smallest and last tube the air flows through before it reaches the alveoli is the
a. tertiary bronchiole
b. terminal bronchiole
c. respiratory bronchiole
d. alveolar duct
d. alveolar duct
The total surface area of all the alveoli is huge, about the size of a
a. large garbage can
b. telephone booth
c. handball court
d. football field
c. handball court
In conditions of hypoxia (low oxygen level)
a. both pulmonary and systemic blood vessels constrict, reducing blood flow
b. pulmonary vessels constrict and reduce blood flow, systemic vessels dilate and increase blood flow
c. pulmonary blood vessels dilate and increase blood flow, systemic blood vessels constrict and reduce blood flow
d. both pulmonary and systemic blood vessels dilate, increasing blood flow
b. pulmonary vessels constrict and reduce blood flow, systemic vessels dilate and increase blood flow
Which of the following muscles is NOT an active muscle of forceful expiration?
a. diaphragm
b. rectus abdominis
c. internal intercostals
d. transversus abdominis
a. diaphragm
During normal quiet breathing, the diaphragm descends and the alveolar pressure decreases about
a. 0.5 mm Hg
b. 2 mm Hg
c. 10 mm Hg
d. 100 mm Hg
b. 2 mm Hg
When we inhale
a. both alveolar pressure and intrapleural pressure decrease
b. both alveolar pressure and intrapleural pressure increase
c. alveolar pressure increases and intrapleural pressure decreases
d. alveolar pressure decreases and intrapleural pressure increases
a. both alveolar pressure and intrapleural pressure decrease
A modified respiratory pattern involves a series of convulsive inspirations followed by a single prolonged expiration. This pattern is characteristic of
a. crying
b. sobbing
c. laughing
d. sighing
b. sobbing
After you inhale in a quiet inhalation, which lung volume does not contain any air?
a. residual volume
b. expiratory reserve volume
c. tidal volume
d. inspiratory reserve volume
d. inspiratory reserve volume
Which of the following is NOT a conducting zone action? a) Clean air of debris b) Conduct air into the lungs c) Add water to air d) Warm air e) All of these are actions of the conducting zone.
e) All of these are actions of the conducting zone.
Although air contains about 79 percent nitrogen, very little of it dissolves in blood plasma because of its low solubility coefficient. This is an example of
a. Boyle’s law
b. Dalton’s law
c. Henry’s law
d. the Bohr effect
c. Henry’s law
Which of the following is likely in a patient with pulmonary edema?
a. difficulty exhaling due to increased surface tension
b. difficulty inhaling due to loss of lung elastic fibers
c. decreased rate of gas exchange due to increased diffusion distance
d. increased rate of gas exchange due to decreased diffusion distance
c. decreased rate of gas exchange due to increased diffusion distance
At a partial pressure of 105 mm Hg in the alveoli, the percent saturation of hemoglobin with oxygen in the pulmonary capillaries will be
a. almost 100 percent
b. about 90 percent, depending on the rate of blood flow
c. 80 percent or more, depending on how hard we breathe
d. 75 percent, because the solubility of oxygen in water is low
a. almost 100 percent
At a PO2 of 40 mm Hg (the average partial pressure of oxygen in tissues at rest) the blood will release about _____ of the oxygen it is carrying
a. 10 percent
b. 25 percent
c. 50 percent
d. 90 percent
b. 25 percent
In normal, quiet breathing, the basic rhythm of respiration is determined almost entirely by the autorhythmic cells of the
a. expiratory area
b. inspiratory area
c. pneumotaxic area
d. apneustic area
b. inspiratory area
By age seventy, the vital capacity can decrease as much as
a. 10 percent
b. 20 percent
c. 35 percent
d. 50 percent
c. 35 percent
The most common infectious cause of death in the United States is
a. pneumonia
b. influenza
c. tuberculosis
d. coryza
a. pneumonia
An increase in pulmonary capillary permeability or an increase in pulmonary capillary pressure leads to
a. pulmonary embolism
b. respiratory stress syndrome
c. asthma
d. pulmonary edema
d. pulmonary edema
Which of the following is NOT part of the upper respiratory system?
a) Nose
b) Oral cavity
c) Pharynx
d) Trachea
e) Nasal meatuses
d) Trachea
Which of the following is NOT a factor that determines the rate of pulmonary and systemic gas exchange?
a) Partial pressure difference of gases
b) surface are availability for gas exchange
c) Diffusion distance
d) Molecular weight and solubility of the gases
e) All of these are factors that determine the rate of pulmonary and systemic gas exchange.
e) All of these are factors that determine the rate of pulmonary and systemic gas exchange.
Which of the following is a passageway for air, food and water?
a) Pharynx
b) Larynx
c) Paranasal sinuses
d) Trachea
e) Esophagus
a) Pharynx
Which structure prevents food or water from entering the trachea?
a) Arytenoid cartilage
b) Epiglottis
c) Nasopharynx
d) Thyroid cartilage
e) Paranasal sinus
b) Epiglottis
The gas law that describes the pressure changes that occur during pulmonary ventilation is
a) Boyle’s law
b) Charles’ law
c) Henry’s law
d) The inhalation law
e) The law of partial pressure
a) Boyle’s law
Which structure is located anterior to the esophagus and carries air to the bronchi?
a) Trachea
b) Larynx
c) Nasopharynx
d) Pharynx
e) None of these choices
a) Trachea
Which of the following is the primary gas exchange site?
a) Trachea
b) Bronchiole
c) Nasal sinuses
d) Alveolus
e) Bronchus
d) Alveolus
Which of the below tissues maintains open airways in the lower respiratory system?
a) stratified squamous epithelium with keratin
b) ciliated pseudostratified columnar epithelium with goblet cells
c) hyaline cartilage
d) mucus membrane
e) bone
c) hyaline cartilage
Which of the below tissues provides the functions of the inner layer of the conducting organs?
a) stratified squamous epithelium with keratin
b) ciliated pseudostratified columnar epithelium with goblet cells
c) ciliated cuboidal epithelium with goblet cells
d) transitional epithelium with cilia
e) columnar connective tissue with goblet cells
b) ciliated pseudostratified columnar epithelium with goblet cells
The point where the trachea divides into right and left primary bronchi is a ridge called
a) Carina
b) Secondary bronchioles
c) Parietal pleura
d) Visceral pleura
e) Diaphragm
a) Carina
Which of the below tissues forms the exchange surfaces of the alveolus?
a) stratified squamous epithelium
b) ciliated pseudostratified columnar epithelium with goblet cells
c) simple squamous epithelium
d) hyaline cartilage
e) columnar connective tissue with goblet cells
c) simple squamous epithelium
Which of the following are cells of the alveoli that produce surfactant?
a) Type I alveolar cells
b) Type II alveolar cells
c) Type III alveolar cells
d) Surface cells
e) Macrophages
b) Type II alveolar cells
Which of the following is NOT a factor that affects pulmonary ventilation?
a) Lung compliance
b) Suface tension of alveolar fluid
c) Elastic recoil of the chest wall and lungs
d) Airway resistance
e) All of these are factors that affect pulmonary ventilation
e) All of these are factors that affect pulmonary ventilation
Which of the following indicates the direction of diffusion of gases at the alveoli of the lungs?
a) Oxygen into blood, Carbon dioxide into blood
b) Oxygen out of blood, Carbon dioxide into blood
c) Oxygen into blood, Carbon dioxide out of blood
d) Oxygen out of blood, Carbon dioxide out of blood
c) Oxygen into blood, Carbon dioxide out of blood
Exhalation begins when
a) Inspiratory muscles relax
b) Diaphragm contracts
c) Blood circulation is the lowest
d) Both Inspiratory muscles relax and Diaphragm contracts
e) All of these choices
a) Inspiratory muscles relax
Which of the following is the sum of the residual and the expiratory reserve volume?
a) Total lung capacity
b) Functional residual capacity
c) Inspiratory capacity
d) Vital capacity
e) Minimal volume
b) Functional residual capacity
Which of the following is NOT a factor that the rate of pulmonary and systemic gas exchange depends on?
a) Partial pressure difference of the gases
b) Surface area for gas exchange
c) Diffusion distance
d) Molecular weight and solubility of the gases
e) Force of contraction of diaphragm
e) Force of contraction of diaphragm
Which of the following is the dominant method of carbon dioxide transport?
a) Bound to hemoglobin
b) Bound to oxygen
c) Dissolved in plasma as a gas
d) Dissolved in plasma as bicarbonate ions
e) Diffusion
d) Dissolved in plasma as bicarbonate ions
When blood pH drops, the amount of oxyhemoglobin _____ and oxygen delivery to the tissue cells _____.
a) Increases, increases
b) Increases, decreases
c) Decreases, increases
d) Decreases, decreases
e) Does not change, does not change
c) Decreases, increases
Which of the following is a factor that does NOT affect hemoglobin’s affinity for oxygen?
a) pH of blood
b) Partial pressure of the oxygen
c) Amount of oxygen available
d) Temperature
e) Respiratory rate
e) Respiratory rate
Where are the nasal conchae?
a) A
b) C
c) T
d) U
e) V
b) C
Which tonsils are found in the oropharynx?
a) V
b) R
c) S
d) Q
e) U
b) R
What structure is also referred to as the Adam’s Apple?
a) G
b) H
c) I
d) J
e) K
d) J
Where is the larynx?
a) I
b) M
c) L
d) N
e) O
a) I
Where is the uvula?
a) E
b) F
c) Q
d) S
e) U
d) S
Where are the palatine tonsils?
a) E
b) F
c) R
d) U
e) None of these choices
c) R
Where is the soft palate?
a) C
b) E
c) G
d) Q
e) S
b) E
Where is the epiglottis?
a) O
b) R
c) S
d) F
e) Q
a) O
Where are the olfactory receptors found?
a) A
b) B
c) C
d) D
e) U
b) B
Where is the middle nasal concha?
a) A
b) B
c) C
d) D
e) E
b) B
Where is the inferior nasal concha?
a) A
b) B
c) C
d) D
e) E
c) C
What is E pointing to?
a) Soft palate
b) Ethmoid bone
c) Hard palate
d) Nasal septum
e) Air cells
d) Nasal septum
What is line D pointing to?
a) Thyrohyoid membrane
b) Corniculate cartilage
c) Cricothyroid ligament
d) Cricoid cartilage
e) Tracheal cartilage
b) Corniculate cartilage
Where is the cricoid cartilage?
a) D
b) E
c) F
d) G
e) H
e) H
Where is the tracheal cartilage?
a) J
b) I
c) H
d) G
e) F
a) J
What is line A pointing to?
a) Hyoid bone
b) Trachea
c) Adams Apple
d) Thyroid
e) Epiglottis
e) Epiglottis
What is line J pointing to?
a) Right secondary bronchus
b) Left secondary bronchus
c) Right primary bronchus
d) Left primary bronchus
e) Carina
d) Left primary bronchus
Where is the right bronchiole?
a) F
b) G
c) H
d) L
e) M
b) G
What lines are pointing to tertiary bronchi?
a) E and K
b) D and J
c) F and L
d) H and M
e) A and B
c) F and L
What is line B pointing to?
a) Carina
b) Visceral pleura
c) Parietal pleura
d) Pleural cavity
e) Diaphragm
c) Parietal pleura
Which letter represents the primary gas exchange structure?
a) A
b) B
c) C
d) E
d) E
What is line C pointing to?
a) Terminal bronchiole
b) Respiratory bronchiole
c) Alveolar ducts
d) Alveolar sac
e) Alveoli
c) Alveolar ducts
Where is the terminal bronchiole?
a) A
b) B
c) C
d) D
e) E
a) A
Which structure provides disease resistance within the lungs?
a) A
b) B
c) C
d) D
e) None of these choices
d) D
Which cells are the main sites of gas exchange?
a) A
b) B
c) C
d) D
e) All of these choices
c) C
Which cell secretes surfactant?
a) A
b) B
c) C
d) D
e) None of these choices
a) A
Describe the inward forces of elastic recoil, and explain why the lungs do not normally collapse during expiration.
Elastic recoil is the recoil of elastic fibers stretched during inspiration and the pull of the surface tension of alveolar fluid. Intrapleural pressure is always subatmospheric during normal breathing, which tends to pull lungs outward and to keep alveolar pressure from equalizing with atmospheric pressure. Surfactant in alveolar fluid decreases surface tension to help prevent collapse.
Why is epinephrine injected as a treatment for the respiratory signs and symptoms of anaphylaxis?
Epinephrine enhances sympathetic activity to dilate airways and decrease airway resistance, which had been elevated by the effects of histamine on the bronchioles. It also raises blood pressure, which enhances oxygen delivery to tissues by increasing flow.
Describe and explain the effects of smoking on the functioning of the respiratory system
Nicotine constricts terminal bronchioles to increase airway resistance, as does the increased mucus secretion and swelling of the mucosa. Smoke inhibits the movement of cilia, which allows buildup of substances and microbes normally removed. Over time, smoking leads to destruction of elastic tissue, which decreases compliance, and ultimately to the effects of emphysema.
Describe the neural, chemical, and physical changes that increase the rate and depth of ventilation during exercise.
: Anticipation of exercise generates neural input to the limbic system. Sensory input is provided from proprioceptors and motor input is provided from the primary motor cortex. As the partial pressure of oxygen falls due to increased consumption, the partial pressure of carbon dioxide and the temperature increase due to metabolic activity in muscle fibers. Also, carbon dioxide is added via the buffering of the hydrogen ions produced as a result of lactic acid production. Chemoreceptors sense the changes in partial pressure and notify the medullary rhythmicity center to increase the rate and depth of breathing.
In chronic emphysema, some alveoli merge together and some are replaced with fibrous connective tissue. In addition, the bronchioles are often inflamed, and expiratory volume is reduced. Using proper respiratory system terminology, explain at least four reasons why affected individuals will have problems with ventilation and external respiration.
reduced compliance (reduces ability to increase thoracic volume); increased airway resistance (decreases tidal volume); decreased diffusion due to increased diffusion distance, decreased surface area, and changes in partial pressures of gases (altering gradients). Other answers may be acceptable.
Normal quiet breathing is controlled by the?
a) Pontine respiratory group
b) Medullary respiratory center dorsal respiratory group
c) Medullary respiratory center ventral respiratory group
d) Medullary respiratory center dorsal respiratory group and medullary respiratory center ventral respiratory group
e) all of these
e) all of these
What area in the figure is the sum of the tidal volume and the inspiratory reserve volume?
a) A
b) B
c) G
d) E
e) H
d) E
What area in the figure is the sum of the tidal volume and the inspiratory reserve volume and expiratory reserve volume?
a) H
b) B
c) G
d) E
e) F
e) F
What area in the figure is the sum of the vital capacity and residual volume?
a) B
b) A
c) G
d) D
e) F
c) G
What area in the figure is the sum of the residual volume and the expiratory reserve volume?
a) H
b) A
c) G
d) E
e) F
a) H
What area in the figure represents a very deep inhalation, much greater than the tidal volume?
a) B
b) A
c) G
d) E
e) F
b) A
What area in the figure represents the volume of a normal breath?
a) B
b) A
c) G
d) E
e) F
a) B
What area in the figure represents the volume of air remaining in the lungs after a deep exhalation?
a) C
b) H
c) D
d) B
e) G
c) D
What area in the figure represents a very deep exhalation, much greater than the tidal volume?
a) C
b) H
c) D
d) B
e) G
a) C
Which of the following is a forced exhalation against the closed rima glottidis as may occur during periods of straining while defecating?
a) sobbing
b) coughing
c) crying
d) hiccupping
e) Valsalva maneuver
e) Valsalva maneuver
Which of the following is a spasmodic contraction of the diaphragm followed by spasmodic closure of the rima glottidis, which produces a sharp sound on inhalation?
a) sneezing
b) coughing
c) laughing
d) hiccupping
e) Valsalva maneuver
d) hiccupping
Which of the following is an inhalation followed by many short convulsive exhalations during which the rima glottidis remains open and the vocal folds vibrate, accompanied by characteristic facial expressions?
a) sneezing
b) yawning
c) hiccupping
d) laughing
e) Valsalva maneuver
d) laughing
Which of the following is an inhalation followed by many short convulsive exhalations during which the rima glottidis remains open and the vocal folds vibrate, accompanied by characteristic facial expressions?
a) sneezing
b) yawning
c) hiccupping
d) crying
e) Valsalva maneuver
d) crying
Which of the following is a series of convulsive inhalations followed by a single prolonged exhalation where the rima glottidis closes earlier than normal after each inhalation so only a little air enters the lung with each inhalation?
a) sobbing
b) sneezing
c) coughing
d) hiccupping
e) Valsalva maneuver
a) sobbing
Which of the following is a deep inhalation through a widely opened mouth producing an exaggerated depression of the mandible, the precise cause of which is unknown?
a) sobbing
b) yawning
c) coughing
d) laughing
e) hiccupping
b) yawning
Which of the following is a long drawn and deep inhalation immediately followed by a shorter but forceful exhalation?
a) sobbing
b) yawning
c) sighing
d) hiccupping
e) Valsalva maneuver
c) sighing
Which of the following is a spasmodic contraction of the muscles of exhalation that forcefully expels air through the nose and mouth?
a) sobbing
b) sneezing
c) coughing
d) sighing
e) Valsalva maneuver
b) sneezing
Which of the following is a long drawn and deep inhalation followed by a complete closure of the rima glottidis, which results in a strong exhalation, pushing the rima glottidis open and sending a blast of air through the upper respiratory passages?
a) crying
b) sneezing
c) coughing
d) sighing
e) Valsalva maneuver
c) coughing
Which structure in the figure is the hyoid bone?
a) A
b) B
c) D
d) F
e) G
a) A
Which structure in the figure is the ventricular fold?
a) F
b) D
c) C
d) E
e) G
c) C
Which structure in the figure is the vocal fold?
a) F
b) D
c) C
d) E
e) G
d) E
Where is the rhythmicity center for respiration?
a) in the medulla
b) in the pons
c) in the cerebrum
d) in the hypothalamus
e) in the cerebellum
a) in the medulla
With which body system does the respiratory system work to regulate the pH of body fluids?
a) muscular
b) digestive
c) nervous
d) endocrine
e) urinary
e) urinary
