Chapter 6: The Respiratory System

Question 1

Air enters the respiratory tract through the external ________ of the nose and then passes through the nasal cavity, where it is filtered by mucous membranes and nasal hairs (____________).

Answer 1

nare; vibrissae

Question 2

After the nares, air passes into the ________ and the ________.

Answer 2

pharynx, larynx

Question 3

The ____________ resides behind the nasal cavity and at the back of the mouth. It is a common pathway for both air destined for the lungs and food destined for the esophagus.

Answer 3

pharynx

Question 4

The ________ lies below the pharynx and is only a pathway for air.

Answer 4

larynx

Question 5

To keep food out of the respiratory tract, the opening of the larynx, the ________, is covered by the ____________ during swallowing.

Answer 5

glottis, epiglottis

Question 6

The larynx contains 2 ________ ________ that are maneuvered using skeletal muscle and cartilage.

Answer 6

vocal cords

Question 7

From the larynx, air passes into the cartilaginous ________ and then into 1 of 2 mainstem ________.

The bronchi and trachea contain ciliated epithelial cells - why?

Answer 7

trachea; bronchi

To catch any material that has made it past the mucous membranes in the nose and mouth

Question 8

In the lungs, the bronchi divide into smaller structures known as ____________, which divide further until they end in the tiny balloon-like structures in which gas exchange occurs, these are ____________.

Answer 8

bronchioles; alveoli

Question 9

Each alveolus is coated with ____________, a detergent that lowers surface tension and prevents the alveolus from collapsing on itself.

Answer 9

surfactant

Question 10

Each alveolus is surrounded by a network of ____________ to carry oxygen and carbon dioxide.

Answer 10

capillaries

Question 11

The lungs themselves are contained in the thoracic cavity, which also contains the heart. The chest ________ forms outside the thoracic cavity.

Answer 11

wall

Question 12

Membranes known as ____________ surround each lung. It forms a closed sac against which the lung expands. The surface adjacent to the lung is the ____________ ________, and the outer part is the ____________ ________.

Answer 12

pleurae; visceral pleura, parietal pleura

Question 13

The lungs do not fill passively, they require ____________ ________ to generate the negative pressure for expansion.

Answer 13

skeletal muscle

Question 14

The ____________ is a thin, muscular structure that divides the thoracic (chest) cavity from the abdominal cavity.

Answer 14

diaphragm

Question 15

The diaphragm is under ________ control, although breathing itself is under ________ control.

Answer 15

somatic; autonomic

Question 16

The space within the sac that surrounds the lung is referred to as ________________ ________, which contains a thin layer of fluid, which helps lubricate the 2 pleural surfaces.

Answer 16

intrapleural space

Question 17

The pressure ________________ that can be created across the pleura ultimately drive breathing.

Answer 17

differentials

Question 18

Inhalation is an active process. We use our diaphragm as well as the ____________ ____________ muscles (one of the layers of muscles between the ribs) to expand the thoracic cavity.

Answer 18

external intercostal

Question 19

As the diaphragm flattens and the chest wall expands outward, the ________________ ____________ (the volume of the chest cavity) increases.

Answer 19

intrathoracic volume

Question 20

Because the intrapleural space most closely abuts the chest wall, its volume increases (first/last?).

Answer 20

first

Question 21

When you inhale, the diaphragm flattens and chest wall expands outward, which creates low pressure in the intrapleural space. The gas in the lungs is initially at atmospheric pressure, but is now (lower/higher?) than the pressure in the intrapleural space.

What happens then? WHat is this called?

Answer 21

higher; the lungs will expand into the intrapleural space and the pressure in the lungs will drop, causing air to be sucked in from a higher-pressure environment (from the outside world)

This is known as negative-pressure breathing, because the driving force is lower (negative) pressure in the intrapleural space compared with the lungs

Question 22

Exhalation does not have to be an active process. Simple relaxation of the ____________ ____________ muscles will reverse inhalation processes. This causes chest cavity to decrease in volume.

Answer 22

external intercostals

Question 23

As the diaphragm and external intercostals relax, the intrapleural space is (lower/higher?) than in the lungs, which is still at atmospheric pressure. This causes air to be pushed out.

Answer 23

higher

Question 24

During active tasks, we can speed up the process of inhalation by using the ____________ ________________ muscles and abdominal muscles, which oppose the external intercostals and pull the rib cage down.

Answer 24

internal intercostal

Question 25

A ____________ is used to measure lung capacities and volumes.

Answer 25

spirometer

Question 26

____________________ is the max volume of air in the lungs when one inhales completely? Usually 6 to 7 liters.

Answer 26

Total lung capacity

TLC

Question 27

____________ is the volume of air remaining in the lungs when one exhales completely.

Answer 27

residual volume

RV

Question 28

________ ____________ is the difference between the min and max volume of air in the lungs.

Answer 28

vital capacity

TLC- RV

Question 29

________ ____________ is the volume of air inhaled or exhaled in a normal breath.

Answer 29

tidal volume

TV

Question 30

____________ ________ ________ is the volume of additional air that can be forcibly exhaled after a normal exhalation.

Answer 30

expiratory reserve volume

ERV

Question 31

________________ ____________ ____________ is the volume of additional air that can be forcibly inhaled after a normal inhalation

Answer 31

inspiratory reserve volume

IRV

Question 32

Ventilation is primarily regulated by a collection of neurons in the medulla oblongata called the ____________ ________ that fire rhythmically to regular contract of respiratory muscles.

Answer 32

ventilation center

Question 33

In the ventilation center, neurons contain ________________ that are primarily sensitive to carbon dioxide concentration.

Answer 33

chemoreceptors

Question 34

As the partial pressure of carbon dioxide in the blood rises (hypercarbia or hypercapnia), the ________________ ________ will increase so that more carbon dioxide is exhaled, causing CO2 levels in the blood to fall.

Answer 34

respiratory rate

Question 35

The ventilation center neurons also respond to changes in oxygen concentration, although this tends to have significance only during period of significant ____________ (low O2 concentrations in the blood).

Answer 35

hypoxemia

Question 36

Each alveolus is surrounded by a network of capillaries, which bring deoxygenated blood from the pulmonary ____________, which originate from the right ____________ of the heart.

Answer 36

arteries; ventricle

Question 37

Where do pulmonary arteries originate from?

Answer 37

right ventricle

Question 38

The walls of the alveoli are only one cell thick, which facilitiates the diffusion of ____ from the blood into the lungs, and ____ into the blood.

Answer 38

CO2, O2

Question 39

The oxygenated blood returns to the left ____________ of the heart via the pulmonary ________.

Answer 39

atrium; veins

Question 40

What drives gas exchange in the alveoli?

Answer 40

pressure differential

Question 41

WHen blood arrives at the alveoli, it intially has a relatively low partial pressure of ____ and a relatively high partial pressure of ____, facilitating transfer of each down its respective concentration gradient.

Answer 41

O2, CO2

Question 42

Because the gradient between the blood and air in the lungs is already present as the blood enters the lungs, how much energy is required for gas transfer?

Answer 42

None

Question 43

At higher altitudes, we would have to breathe (quicker/slower).

Answer 43

quicker

Question 44

The natural response of hemoglobin to the decreased CO2 concentration would be to (increase/decrease?) the unloading of oxygen to tissues.

Answer 44

decrease

Question 45

In the short term, the body can do what to in order to ensure O2 delivery in high altitudes?

Answer 45

make more red blood cells

Question 46

In the long term, what can the body do to ensure O2 delivery in high altitudes?

Answer 46

facilitate the distribution of oxygen to tissues

Question 47

The respiratory tract can also be used for ____________ because it is highly vascular.

Answer 47

thermoregulation

Question 48

Heat is regulated via the body surfaces by ____________ and ________________.

Answer 48

vasodilation and vasoconstriction

Question 49

As capillaries expand, more blood can pass through these vessels and a larger amount of thermal energy can be dissipated. What happens when they contract?

Answer 49

Less blood passes through, conserving thermal energy

Question 50

Which capillaries are used for thermoregulation?

Answer 50

nasal and tracheal

Question 51

The first line of defense in the respiratory system is ?

Answer 51

the nasal cavity’s vibrissae

Question 52

what enzyme in the nasal cavity attacks the peptidoglycan walls of gram-positive bacteria?

Answer 52

lysozyme

Question 53

The internal airways are lined with ____________, which traps particulat matter and larger invaders. Underlying cilia then propel the mucus up the respiratory tract to the oral cavity, where it can be expelled or swallowed; this is called the ________________ ____________.

Answer 53

mucus; mucociliary escalator

Question 54

____________ can engulf and digest pathogens and signal to the rest of the immune system that there is an invader.

Answer 54

macrophages

Question 55

Mucosal surfaces also contain ____ antibodies that help to protect against pathogens that contact the mucous membranes.

Answer 55

IgA

Question 56

________ cells also populate the lungs; they have preformed antibodies on their surfaces. When the right substance attaches to the antibody, this cell releases inflammatory chemicals to promote an immune response.

Answer 56

mast

Question 57

Mast cell antibodies are also usually reactive to substances like ________ and ________, so they provide inflammatory chemicals that mediate allergic reactions.

Answer 57

pollen and mold

Question 58

What is the bicarbonate buffer system?

Answer 58

reference p236-237