Anatomy 2146: Respiratory System

If the tidal volume is 375 mL, and the anatomical dead space is increased from 150 mL to 375 mL, how much fresh air enters the alveoli, (i.e., what is the new alveolar ventilation)?

0 mL

Name the structures of the lower respiratory tract.

larynx, trachea, bronchi, and lungs

Name the structure that contains the vestibular and vocal folds. What protected function do these folds have?

larynx; help preven foreign particles from entering the lower respiratory system

This passageway divides into two _____, which upon entering the lungs, continue to divide into smaller _____ until they ultimately divide into ______.

primary bronchi; bronchi; terminal broncioles

____ form a network around each alveolus.

pulmonary capillaries

Another term for breathing is _____.

pulmonary ventilation

What effect does carbon dioxide delivered to the lungs from the blood have on this number?

raises PCO2 to 40

How does the elevation of the ribs affect the thoracic cavity width? This motion is similar to _____.

raising the handle of a bucket

What are alveoli? Where are they located?

small saccular outpocketings of the respiratory bronchioles and alveolar ducts; lungs

At the end of inspiration, _____.

thorax and alveoli stop expanding

Name the organ that maintains an open passageway to and from the lungs. What particular structure helps to keep this passageway open?

tracheobronchial tree; C-shaped cartilages

The blood now carries the ____ to the _____.

CO2 and O2; lungs

Assume that the alveolar ventilation is (mean tidal volume minus 150 mL) * breathing rate. What was the alveolar ventilation immediately after exercise?

About 12000 mL/min

If the volume of the anatomical dead space is not changed by exercise, how much extra air entered the alveoli due to the exercise-induce increase in tidal volume?

About 200 mL

If the volume of the anatomical dead space volume is about 150 mL, how much fresh air entered the alveoli during each breath when the virtual volunteer was at rest?

About 325 mL

Assume that the alveolar ventilation is (mean tidal volume - 150 mL) * breathing rate. What was the alveolar ventilation at rest?

About 4000 mL/min

One hemoglobin molecule can bind as many as:

FOUR molecules of oxygen.

Describe the direction of diffusion of oxygen and carbon dioxide in the alveoli.

At the arterial ends of the pulmonary capillaries, O2 diffuses from the air into the alveoli into the blood and CO2 diffuses from the blood into the alveoli

Look at the curves on your graph, about one-third of the way from zero mark on the horizontal axis (a PO2 value around 50 mm Hg). Imagine a vertical line that intersects the curves.

Blood with a lower pH has a lower transmittance value (âcolorâ).

The exchange of oxygen and carbon dioxide between the air in the lung and the pulmonary blood supply takes place:

across the walls of the alveoli.

The air in the anatomical dead space:

all of the other options are correct.

At the alveoli, the diffusion of gases between the air and blood is facilitated by:

all of the other options are true.

The amount of oxygen that binds to hemoglobin depends upon:

all of the other options are true.

At PO2 levels around 50 mm Hg (approximately the same PO2 value found in the tissues), a lower pH:

decreases the amount of bound oxygen; i.e., hemoglobin releases more oxygen to the tissues.

Pulmonary capillaries close if the arterial blood pressure:

decreases.

The oxygen dissociation curve shows that as the partial pressure of oxygen is decreased to a very low level, the amount of oxygen bound to hemoglobin:

decreases.

When a fluid (like blood) travels against the force of gravity, the pressure:

decreases.

What changes occur with the diaphragm and the thoracic cavity during expiration?

diaphragm is elevated as it relaxes and the length of the thoracic cavity decreases

Look at your data for vital capacity, recorded from the virtual volunteer at rest and immediately after exercise. Exercise:

did not really change the vital capacity.

This occurs because of _____.

differences in partial pressures

What causes the diffusion of gases across this membrane? Explain it for both oxygen and carbon dioxide.

diffuse across respiratory membrane due to differences in partial pressure; O2 diffuses from high PO2 in the alveolus to a low P02 in pulmonary capillaries; CO2 diffuses from high PCO2 in blood to low PCO2 in alveolus

Each ____ divides repetitively to form ______, ______, and ______.

bronchiole; branchioles; alveolar ducts; and alveolar sacs

What is the partial pressure of carbon dioxide in fresh air entering the lungs?

PCO2 of 0.3

What is the partial pressure of oxygen in fresh air entering the lungs?

160

If the tidal volume is 375 mL and the anatomical dead space is 150 mL, what is the alveolar ventilation?

225 mL

If the tidal volume is 375 mL and the anatomical dead space is increased from 150 mL to 350 mL, what is the new alveolar ventilation?

25 mL

What is the diameter of the alveolus? How many are in each lung?

250 micrometers; millions

This structure has a thickness of only _____, which facilitates ______.

5 micrometers; rapid exchange of CO2 from the blood into the alveolus and O2 from the alveolus into the blood

Look at your data. How did exercise change the expiratory reserve volume; this is the amount of air forced out of the lungs after the volunteer exhaled normally?

Exercise decreased the expiratory reserve volume.

Exercise increased the amount of air entering the alveoli by more than 50%. What happened to the breathing rate?

Exercise increased the breathing rate.

When compared with normal breathing, what happened to the mean tidal volume when the virtual volunteer breathed through the tube?

It increased.

What occurs at the venous ends of the tissue capillaries?

PO2 in blood=PO2 in tissue fluid; PCO2 in blood=PCO2 in the tissue fluid

Do you think that breathing through the plastic tube changed the metabolic rate of the volunteer?

No, it did not significantly increase the metabolic rate.

In a person who is lying down, gravity will create the lowest blood pressure:

None of the other options are correct. The effect of gravity will be less than in a standing person.

How do oxygen and carbon dioxide move between the blood and the alveoli?

O2 diffuses across this membrane into the blood and CO2 moves from the blood back into the air where it is expelled during exhalation

How do oxygen and carbon dioxide diffuse into/out of the tissue capillaries?

O2= out of arterial ends of tissue capillaries into tissue fluid then into cell; C)2= out into tissue fluid--> blood

What occurs as a result of diffusion at the venous ends of the pulmonary capillaries>

P02 in blood=P02 in alveoli; PCO2 in blood=PCO2 in alveoli

Which of the following is true?

The anatomical dead space is not really changed by exercise.

Which of the following do you think would be increased by breathing through the plastic tube?

The anatomical dead space.

When lying down, blood pressure is uniform and the capillaries in the lung are open. What happens to the surface area for gas exchange when a person lies down?

The surface for gas exchange increases when the person lies down.

During the breathing cycle, air enters the alveoli and the airways. If the airway volume is about 150 mL, according to your data, how much air entered the alveoli when the volunteer was standing?

The tidal volume -â the airway volume; about 225 mL.

During the breathing cycle, air enters the alveoli and the airways. If the airway volume is 150 mL, according to your data, how much air entered the alveoli when the volunteer was lying down?

The tidal volume minus the airway volume; about 150 mL.

What happened to the amount of fresh air entering the alveoli when the virtual volunteer lay down and the tidal volume decreased?

The volume of air entering the alveoli decreased.

A solution with a pH below 7 is said to be:

acidic.

Look at your graph. A high transmittance value (âcolorâ) indicates:

a large amount of oxygen is bound to hemoglobin.

If breathing through the tube increased the tidal volume by about 200 mL, what was the volume of the tube?

about 200 mL

In your experiemnt, breathing through the tube increased the tidal volume by:

about 200 mL

Air continues to flow out of the lungs until ______.

alveolar pressure become equal to barometric pressure

Air flow into the lungs causes _____.

alveolar pressure to become equal to barometrial air pressure

The ____ is now ____ than _____, so air flows ______ of the lungs.

alveolar pressure; greater; barometric air pressure; out

What structure serves as the site for gas exchange? These rounded structures are surrounded by ______.

alveoli; pulmonary capillaries

You are breathing normally and then inhale an extra 50 mL of fresh air. This will result in:

an extra 50 mL of fresh air entering the alveoli.

This occurs at the ____ ends of the _____.

arterial; pulmonary capillaries

Blood flow through pulmonary capillaries is dependent upon the blood pressure. In a standing individual, therefore, the pulmonary capillaries will most likely be closed:

at the apex of the lung, above the heart.

The pressure of a fluid decreases as it travels against gravity. In a standing person the part of the lung with the lowest blood pressure will be:

at the apex of the lung, above the heart.

At the end of expiration, _____.

barometric air pressure and alveolar air pressure are equal

In most multicellular organisms, the fluid that circulates materials around the body is called:

blood.

The compensatory change that occurred in the virtual volunteer to maintain a constant amount of air entering the alveoli was by:

both of the other options are correct.

Cells make hydrogen ions because they can produce:

both of the other options are true.

What is this thin structure composed of?

capillary endothelial cell, alveolar type I epithelial cell and their fluid basement membranes

What regulates the length of the thoracic cavity?

changes of shape of the thoracic diaphragm

What effect does the nasal cavity have on inhaled air?

cleaned, warmed, and dehumidified air

Inspiration begins with ____ of the ____ to ____.

contraction; inspiratory muscles; increase thoracic volume

The increased alveolar pressure causes a ____ in ____ below ___ and ____ flows ______.

decrease; alveolar pressure; barometric pressure; air; into the lungs

This results in a _____ in _____ and an _____ in ______.

decrease; alveolar volume; increase alveolar pressure

According to your results, changing body position from standing to lying:

decreased the tidal volume.

This results in ______.

expansion of the lungs and can increase in alveolar volume

Name the structures of the upper respiratory tract.

external nose, nasal cavity, and pharynx

How is the length of the the thoracic cavity increased during inspiration?

flattening and descent of dome-shaped diaphragm when it contracts

The plastic tube caused the anatomical dead space to artificially:

increase in size.

How does the movement of the sternum and ribs facilitate inspiration?

increase in volume and decrease in pressure in the thoracic cavity

If you artificially increase the anatomical dead space by 200 mL, you can maintain a constant alveolar ventilation by:

increasing the tidal volume by 200 mL. That answer is correct.

During exercise, the increase in the body's oxygen requirements is met by:

increasing tidal volume and breathing rate.

In humans, hemoglobin is found:

inside red blood cells.

Both ____ and _____ result from changes in ____ in the ____.

inspiration; expiration; volume; thoracic cavity

What regulates the depth and width of the thoracic cavity? How?

intercostal muscles; alternatively elevate and depress the ribs/sternum

In a person who is lying down, if more capillaries are open, the tidal volume will be:

lower than when standing, because the increased surface area allows more efficient gas exchange.

After exercise, if there were less (stale) air left in the lungs after the virtual volunteer exhaled the larger tidal volume would mean that when the virtual volunteer took a breath:

more fresh air entered the alveoli and mixed with less stale air.

At the tissues, a low pH pushes the oxygen dissociation curve to the right so that:

more oxygen is released, which leaves less oxygen bound to hemoglobin.

What are the two functions of the respiratory system?

move air into/out of lungs and provides a surface for gas exchange

What effect does this elevation of the ribs have on the sternum? What effect does this have on the thoracic cavity depth?

moves anteriorly and superiorly; increases thoracic cavity depth

Decreasing the pH of the blood (making it more acidic):

moves the oxygen dissociation curve to the right.

Hydrogen ions bind to the beta-chains of hemoglobin and decrease the affinity of hemoglobin for oxygen. Therefore, lowering the pH:

moves the oxygen dissociation curve to the right.

The pressure becomes equal, so _____.

no more movement of air occurs

Therefore, _____.

no movement of air into or out of the lungs takes place

Oxygen and carbon dioxide exchange takes place between the blood and the air in the (human) lungs across the walls of:

only the alveoli.

Name the structure shared by both the respiratory and digestive systems.

pharynx

What effect does moisture in the lungs have on this number?

reduction of P02 to 104

Name the thin structure that separates the capillary blood from the air in the alveolus.

respiratory membrane

What structures drive these changes?

respiratory muscles

Look at your data for tidal volume, recorded from the virtual volunteer at rest and immediately after exercise. Exercise:

significantly increased the tidal volume.

In the body, all of these exchanges occur _____.

simultaneously

In the lungs, gas exchange takes place _____.

terminal portion of the bronchial tree

During exercise, an increase in the rate of breathing will increase:

the alveolar ventilation.

During exercise, an increase in tidal volume will increase:

the alveolar ventilation.

The alveolar ventilation is:

the amount of air that moves in or out of the alveoli in one minute.

The tidal volume is:

the amount of air that moves in or out of the lungs during any one breathing cycle.

Blood flow to a group of alveoli will decrease if:

the level of oxygen in the alveoli decreases.

The partial pressure of oxygen is:

the portion of the barometric pressure produced by oxygen.

The alveolar ventilation is:

the volume of air that enters the alveoli.

The anatomical dead space is:

the volume of air trapped in the airways.

With no differences in partial pressure, _____.

there is no more net movement of O2 or CO2

The vocal folds are also known as the _____. Why?

true vocal cords; produces sound when air passes between them

The cells that form 90% of the alveolar wall are _____.

type I cells

What are the two types of specialized cells in the wall of the alveoli?

type I= thin, squamous epithelial cells type II= secrete pulmonary surfactant that coats inner surfaces of the alveolus; surfactant reduces surface tension and prevents the collapse of the alveolus

During inspiration, the thoracic cavity increases in ____. Why?

volume; accommodates expansion of the lungs

During expiration, the ____ of the _____ as the ____ _____, and the _____ and the _______ _____.

volume; thorax decreases; diaphragm relaxes; thorax; lungs recoil