Chapter 6: The Respiratory System

Question 1

Air is drawn in through the

Answer 1

nares, and through the nasal cavity and pharynx, where it is warmed and humidified. It is filtered by nasal hairs (vibrissae) and mucous membranes.

It then enters the larynx, followed by the trachea. The trachea divides into two mainstem bronchi, which divide into bronchioles , which divide into continually smaller passages until they reach the alveoli.

(Bronchi, bronchioles, and alveoli)

Question 2

Alveoli are

Answer 2

Alveoli are small sacs that interface with the pulmonary capillaries, allowing gases to diffuse across a one-cell-thick membrane.

O2 in

CO2 out

Question 3

Surfactant in the

Answer 3

Surfactant in the alveoli reduces surface tension at the liquid–gas interface, preventing collapse.

Question 4

The pleurae cover the ___ and line the ___.

Answer 4

Lungs

Chest wall

Question 5

The ___ cover the lungs and line the chest wall.

Answer 5

pleurae

Question 6

The visceral pleura

Answer 6

lies adjacent to the lung itself.

Question 7

The parietal pleura

Answer 7

lines the chest wall.

Question 8

The intrapleural space lies

Answer 8

The intrapleural space lies between these two layers and contains a thin layer of fluid that lubricates the two pleural surfaces.

Question 9

The ___ lies adjacent to the lung itself.

Answer 9

visceral pleura

Question 10

The___ lines the chest wall.

Answer 10

parietal pleura

Question 11

The ____ lies between these two layers and contains a thin layer of fluid that lubricates the two pleural surfaces.

Answer 11

intrapleural space

Question 12

The diaphragm is a

Answer 12

thin, muscular structure that divides the thoracic (chest) cavity** from the **abdominal cavity. the diaphragm is under somatic control, even thru breathing itself is under autonomic control.

Question 13

Inhalation is an___.
Tell me more

Answer 13

active process!! (the lung expand)

• The diaphragm and external intercostal muscles expand the thoracic cavity, increasing the volume of the intrapleural space(b/t other 2 pleura). This decreases the intrapleural pressure.

-Inhale: (increase in volume and decrease in pressure)

• This pressure differential ultimately expands the lungs, dropping the pressure within and drawing in air from the environment. This mechanism is termed negative-pressure breathing.

Question 14

Exhalation may be ___.
Tell me more

Answer 14

passive or active

• In passive exhalation, relaxation of the muscles of inspiration and elastic recoil of the lungs allow the chest cavity to decrease in volume, reversing the pressure differentials seen in inhalation.

*• In active exhalation, the internal intercostal muscles and abdominal muscles can be used to forcibly decrease the volume of the t_horacic cavity_, pushing out air.

Exhale: ( decrease the volume and increase the pressure)

Question 15

A spirometer can be used to

Answer 15

measure lung capacities and volumes.

Question 16

A ____ can be used to measure lung capacities and volumes.

Answer 16

spirometer

Question 17

Total lung capacity (TLC) is the

Answer 17

is the maximum volume of air in the lungs when one inhales completely.

Question 18

Residual volume (RV) is the

Answer 18

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

Question 19

Vital capacity (VC) is the

Answer 19

difference between the minimum and maximum volume of air in the lungs.

Question 20

Tidal volume (TV) is the

Answer 20

volume of air inhaled or exhaled in a normal breath.

Question 21

Expiratory reserve volume (ERV) is the

Answer 21

volume of additional air that can be forcibly exhaled after a normal exhalation.

Question 22

Inspiratory reserve volume (IRV) is the

Answer 22

volume of additional air that can be forcibly inhaled after a normal inhalation.

Question 23

Ventilation is regulated by the___, a collection of neurons in the___.

Answer 23

ventilation center

Medulla Oblongata

****

• Chemoreceptors respond to carbon dioxide concentrations, increasing the respiratory rate when there is a high concentration of carbon dioxide in the blood (hypercarbia or hypercapnia). (high CO2)
• The ventilation center can also respond to low oxygen concentrations in the blood (hypoxemia) by increasing ventilation rate.
• Ventilation can also be controlled consciously through the cerebrum, although the medulla oblongata will override the cerebrum during extended periods of hypo-or hyperventilation.

Question 24

Title:

Functions of the Respiratory System

Answer 24

START

Question 25

The lungs perform gas exchange with the blood through

Answer 25

simple diffusion across concentration gradients.

Question 26

Deoxygenated blood with a high carbon dioxide concentration is brought to the lungs via the

Answer 26

pulmonary arteries

Question 27

Oxygenated blood with a low carbon dioxide concentration leaves the lungs via the

Answer 27

pulmonary veins

Question 28

The large surface area of interaction between the alveoli and capillaries allows the respiratory system to assist in thermoregulation through

Answer 28

vasodilation and vasoconstriction of capillary beds.

Question 29

The respiratory system must be protected from potential pathogens.

Answer 29

• Multiple mechanisms, including vibrissae, mucous membranes, and the mucociliary escalator, help filter the incoming air and trap particulate matter.
• Lysozyme in the nasal cavity and saliva attacks peptidoglycan cell walls of gram-positive bacteria.
• Macrophages can engulf and digest pathogens and signal to the rest of the immune system that there is an invader.
• Mucosal surfaces are covered with IgA antibodies.
• Mast cells have antibodies on their surface that, when triggered, can promote the release of inflammatory chemicals.

Mast cells are often involved in allergic reactions as well.

Question 30

The respiratory system is involved in pH control through the___.

Answer 30

bicarbonate buffer system

****

• When blood pH decreases(acidic), respiration rate increases to compensate by blowing off carbon dioxide. This causes a left shift in the buffer equation, reducing hydrogen ion concentration.

pH decreases….. respiration rate increase(compensate Blowing off CO2) = left shift in buffer equation, reducing H ion concentration

• When blood pH increases, respiration rate decreases to compensate by trapping carbon dioxide. This causes a right shift in the buffer equation, increasing hydrogen ion concentration.

pH increases, respiration rate decreases (by trapping CO2). = causes right shift in buffer equation, increasing H ion concentration

Question 31

When blood pH decreases

Answer 31

respiration rate increases to compensate by blowing off carbon dioxide. This causes a left shift in the buffer equation, reducing hydrogen ion concentration

pH decreases….. respiration rate increase(compensate Blowing off CO2) = left shift in buffer equation, reducing H ion concentration

pH and respiratory rate are opposite always

Question 32

When blood pH increases

Answer 32

respiration rate decreases to compensate by trapping carbon dioxide. This causes a right shift in the buffer equation, increasing hydrogen ion concentration

pH increases, respiration rate decreases (by trapping CO2). = causes right shift in buffer equation, increasing H ion concentration

Question 33

List the structures in the respiratory pathway, from where air enters the nares to the alveoli�

Answer 33

1. Nares → nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli

Question 34

Which muscle(s) are involved in inhalation? Exhalation?

Answer 34

2. Inhalation uses the diaphragm and external intercostal muscles; in labored breathing, muscles of the neck and back may also be involved.

Passive exhalation uses the recoil of these same muscles; active exhalation also uses the internal intercostal muscles and abdominal muscles.

Question 35

What is the purpose of surfactant?

Answer 35

3. Surfactant reduces surface tension at the air–liquid interface in the alveoli. This prevents their collapse.

Question 36

What is the mathematical relationship between vital capacity (VC), inspiratory reserve volume (IRV), expiratory reserve volume (ERV), and tidal volume (TV)?

Answer 36

4. Vital capacity is the sum of the inspiratory reserve volume, expiratory reserve volume, and tidal volume: VC = IRV + ERV + TV

Question 37

If blood levels of CO2 become too low, how does the brain alter the respiratory rate to maintain homeostasis?

Answer 37

5. When CO2 levels become too low, the brain can decrease the respiratory rate in order to raise CO2 levels.
   - The more CO2 the more acidic
   - The less CO2 the least acidic

Question 38

What are some of the mechanisms used in the respiratory system to prevent infection?

Answer 38

Immune mechanisms in the respiratory system include vibrissae in the nares, lysozyme i_n the mucous membranes_, the mucociliary escalator, macrophages in the lungs, mucosal IgA antibodies, and mast cells.

Question 39

What is the chemical equation for the bicarbonate buffer system?

Answer 39

Equation:

Question 40

Respiratory failure refers to inadequate ventilation to provide oxygen to the tissues. How would the pH change in respiratory failure?

Answer 40

In respiratory failure, ventilation slows, and less carbon dioxide is blown off. As this occurs, the buffer equation shifts to the right, and more hydrogen ions are generated. This results in a lower pH of the blood.

Respiratory failure = less CO2 being blown off –> equation shift to the right –> More H+ attoms

Question 41

Respiratory acidosis is a condition that occurs when the

Answer 41

lungs can’t remove enough of the carbon dioxide (CO2) produced by the body. Excess CO2 causes the pH of blood and other bodily fluids to decrease, making them too acidic. Normally, the body is able to balance the ions that control acidity.

Question 42

The increase in H+ leads to a

Answer 42

decrease in pH (that is, the blood becomes more acidic). If the amount of CO₂ is decreased, the reaction can run in reverse. That is, the HCO₃^– binds the free H+ ions to produce carbonic acid and convert it into CO₂. The blood becomes more alkaline.

Question 43

REAL WORLD:

Answer 43

In some pathologic states, that potential space can be expanded by fluid or air that accumulates between the two pleural layers. For ex, in a plural effusion, fluid accumulates in the intraplural space, in a pneumothorax, air collects here. each of these states disturbs the normal mechanics of the breathing apparatus and can cause atelectasis, or lung collapse.