BIOL 2402 (BLINN) Chapter 22: The Respiratory System

The ____ respiratory group adjusts the respiratory rate based on stimuli from the limbic system or cerebral cortex.

pontine

Which component of the respiratory center is responsible for setting the basal respiratory rate and providing output to the muscles of respiration?

ventral respiratory group

The sum of the expiratory reserve volume, tidal volume, and inspiratory reserve volume is the ____ capacity.

vital

Which factors would decrease the affinity of hemoglobin for oxygen?

- Decreased blood pH - Decreased PO2 of surrounding tissue

Which are examples of obstructive lung disorders?

- asthma - chronic bronchitis

How many oxygen molecules are bound to a fully loaded hemoglobin molecule?

4

Which term refers to the conducting zones of the respiratory system because they are incapable of gas exchange?

Anatomical dead space

According to this figure, most of the carbon dioxide you exhale comes from which of the following?

Bicarbonate ions transported into the RBCs and used to generate free CO2

Why is carbon monoxide a serious health threat?

CO competes with oxygen for the same binding sites

Match each receptor to the type of stimulus it detects

Central chemoreceptors: pH of CSF Peripheral chemoreceptors: oxygen level, carbon dioxide level, and pH of the blood Stretch receptors: inflation of the lungs Irritant receptors: smoke, dust, pollen, chemical fumes, cold air

Which factor is typically responsible for setting the respiratory rate in healthy individuals?

Cerebrospinal fluid pH

_____ Law states that the total pressure of a gas mixture is equal to the sum of individual partial pressures of gases.

Dalton's

Match each of the following to its description.

Oxyhemoglobin: hemoglobin with one or more oxygen molecules bound to it Deoxyhemoglobin: hemoglobin with no oxygen bound to it Carboxyhemoglobin: hemoglobin with carbon monoxide bound to it Carbaminohemoglobin: compound of hemoglobin and carbon dioxide

The lungs of premature infants often develop respiratory distress syndrome. Why do these infants experience alveolar sac collapse?

Surfactant is not produced yet in adequate quantities

What is the intrapleural pressure?

The pressure in the fluid-filled space between the parietal and visceral pleurae

Oxygen loading in the lungs decreases hemoglobin's affinity for H+. How does this promote alveolar gas exchange?

The released H+ combines with HCO3- to form free CO2, which can diffuse out of the blood

What is the normal systemic arterial blood value for PCO2?

40 mm Hg

As the volume of a closed container decreases, the pressure of the gas within it increases. This is an example of which gas law?

Boyle's Law

TRUE OR FALSE: all of the oxygen transported in the blood is usually unloaded at a systemic capillary.

False

TRUE OR FALSE: the residual volume may be exhaled with a forceful expiration.

False

TRUE OR FALSE: The respiratory control centers of the brainstem are involved in voluntary respiration.

False Voluntary respiration bypasses the respiratory centers of the brainstem

During the respiratory cycle, the intake of air is called ____.

Inhalation

Ambient (outside) air is 22C is inhaled. The gases are warmed to body temperature (37.5C) by the time they reach the alveoli of the lungs. According to Charles's Law, what will happen to the volume of the inhaled air?

The volume will increase

TRUE OR FALSE: evidence suggests that ventilation increases more quickly in response to high levels of CO2 than it does to low levels of O2 in the blood.

True

TRUE OR FALSE: the anatomical dead space is subtracted from tidal volume when calculating the alveolar ventilation rate.

True

As the thoracic cavity expands, the visceral pleura clings to the parietal pleura, and the surface of the lung is pulled outward. Why does this increase in lung volume cause inspiration?

Intrapulmonary pressure is temporarily lower than atmospheric pressure

Which type of lung disorder decreases pulmonary compliance and thereby decreases vital capacity?

Restrictive

Where does systemic gas exchange occur?

at the capillary networks of the tissues

Hemoglobin that is NOT bound to oxygen is called ____.

deoxyhemoglobin

Which best defines alveolar gas exchange?

movement of oxygen and carbon dioxide across the respiratory membrane

____ is a general term for a drop in the pH of blood below 7.35.

acidosis

_____ is the collapse of a lobe or lung due to equalizing the intrapleural and atompspheric pressure.

atelectasis

Why does air flow into the lungs during inspiration?

atmospheric pressure is greater than intrapulmonary pressure, and air flows toward the lower pressure area.

Most carbon dioxide in the blood is transported in the form of ____ dissolved in the plasma.

bicarbonate

The peripheral chemoreceptors detect changes in which of the following?

blood oxygen saturation, blood pH, blood carbon dioxide saturation

The enzyme found in erythrocytes catalyzes the formation of carbonic acid, which then dissociates into bicarbonate and hydrogen ions, is ___ ____.

carbonic anhydrase

Irritants in the lower respiratory system may stimulate which of the following?

coughing

The ____ respiratory group receives input from chemoreceptors and adjusts the respiratory rate accordingly.

dorsal

When the diaphragm relaxes, air is forced from the lungs. This process is known as _____.

expiration

The _____ neurons inhibit the inspiratory neurons of the ventral respiratory group.

expiratory

The term ____ describes a condition where there is an excess of CO2 in atrial blood (PCO2 greater than 43 mmHg).

hypercapniaW

The condition called ______ occurs when arterial CO2 concentrations fall below normal. (POC2 less than 37 mm Hg).

hypocapnia

Which of these occurs during exhalation?

lung volumes decrease, intrapulmonary pressure increases

Which describes the respiratory cycle?

one complete inspiration and expiration

When oxygen binds to hemoglobin it forms the molecule called _____

oxyhemoglobin

Central chemoreceptors in the brain stem that are involved in respiratory control respond most directly to changes in which of the following?

pH

Which term refers to the pressure that each individual gas in a mixture would exert if the other gases were not present?

partial pressure

Which is often increased in individuals with pulmonary disease?

physiological dead space

A(n) ______ is a clinical condition characterized by the presence of air in the pleural cavity.

pneumothorax

_____ receptors respond to the degree of inflation of the lungs/alveoli.

stretch

____ refers to a shift in the pH of blood above 7.45.

alkalosis

A person expelling air while yelling is performing which type of breathing?

forced

Which term refers to the volume of air (or percentage of the vital capacity) that can be exhaled in a specific amount of time?

forced expiratory volume

What does this graph illustrate?

higher temperatures promote the unloading of oxygen from hemoglobin

The sum of the tidal and inspiratory reserve volumes is a measure of the ____ capacity.

inspiratory

In a healthy individual, which of these volumes would have the greatest numerical value?

inspiratory reserve volume

Which two muscles (or muscle groups) are primarily responsible for resting (non-forced) inspiration?

intercostals and diaphragm

Which of these calculated volumes typically has the greatest value?

total lung capacity

RBCs usually leave the systematic capillaries at about 75% oxygen saturation. Which term refers specifically to the oxygen remaining in the blood after it passes through a capillary bed?

venous reserve

Which explains why the oxyhemoglobin dissociation curve is nonlinear (s-shaped)?

Binding of the first oxygen molecule to hemoglobin facilitates the binding of additional oxygen, so the mid portion of the curve becomes steeper.

Which is true about carbon dioxide loading?

Carbonic anhydrase catalyzes the conversion of CO2 and H2O into bicarbonate and hydrogen ions.

The functional residual capacity is obtained by adding together which of the following respiratory volumes?

ERV and RV

____ law states that the amount of gas dissolved in water is determined by solubility in the fluid and the partial pressure of the gas in the surrounding air.

Henry's

Match each respiratory volume to its definition.

Residual Volume (RV): the amount of air remaining in the lungs after a forced expiration Expiratory Reserve Volume (ERV): the amount of air that may be exhaled over the tidal volume Forced Expiratory Volume (FEV): the amount of air that can be exhaled in a given time interval Tidal Volume (TV): the amount of air inhaled and exhaled during quiet breathing

Which term refers to the exchange of gases across the respiratory membrane?

alveolar gas exchange

The maximum volume of air that can be exhaled after exhalation of the tidal volume is the ___ ___ volume.

expiratory reserve

Which muscles are used for inspiration?

external intercostals, sternocleiodomastoid, scalenes

Which locations contain the brainstem respiratory centers?

medulla oblongata and pons

____ volume is the volume of air inhaled or exhaled during a respiratory cycle.

tidal

The ______ maneuver entails increasing abdominal pressure by holding a deep breath while contracting the abdominal muscles. The depressed diaphragm increases abdominal pressure and helps push out organ contents during childbirth, urination, and defection.

valsalva

What are the 4 predominant components of inspired air?

- nitrogen - water vapor - carbon dioxide - oxygen

Identify the forms in which carbon dioxide is transported in the blood.

- bicarbonate ion - carbaminohemoglobin - dissolved gas

What occurs during the "chloride shift" in red blood cells?

- chloride ions are transported into the RBC - bicarbonate ions are transported out of the RBC

Which two factors contribute most to airflow resistance?

- diameter of the bronchioles - lung compliance

Which hormones promote oxygen delivery to tissues by stimulating biphosphoglycerate (BPG) synthesis?

- epinephrine - thyroxine - testosterone - growth hormone

Which facts that would decrease the affinity of hemoglobin for oxygen?

- increased bisphosphoglycerate production by RBC - increased temp

What is the normal systemic arterial blood gas value for PO2?

95 mmHg

Deoxygenated blood can carry more carbon dioxide, whereas oxygenated blood has a lower carbon dioxide carry capacity. This phenomenon is known as the ____.

Haldane

Deoxygenated blood can carry more carbon dioxide, whereas oxygenated blood has a lower carbon dioxide carrying capacity. This phenomenon is known as the _______ effect.

Haldane

The Bohr effect occurs because CO2 lowers the pH of the blood, which (as this graph illustrates) facilitates the unloading of oxygen from hemoglobin. Given this, what is the physiological significance of the Bohr effect?

more oxygen is released to tissues that have higher metabolic rates

Which term describes the ease with which lung tissue expands during breathing?

pulmonary compliance

Which process is facilitated by the elastic components of the lungs and bronchial tree?

quiet exhalation

Which would increase the efficiency of alveolar gas exchange?

Breathing air that contains increases levels of oxygen Increasing the air's oxygen content would increase the amount of oxygen that diffuses into the blood