Biology Ch. 6: The Respiratory System

Question 1

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

Answer 1

Nares-> nasal cavity–>pharynx–>larynx–>trachea–>bronchi–>bronchioles–>alveoli

Question 2

Which muscles are involved in inhalation

Answer 2

Inhalation uses the diaphram and the external intercostal muscles
In labored breathing, muscles of the neck and back may also be involved

Question 3

which muscles are used in exhalation

Answer 3

Passive exhalation uses the recoil of the same muscles used in inhalation.
Active exhalation also uses the internal intercostal muscles and abdominal muscles

Question 4

what is the purpose of surfactant

Answer 4

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

Question 5

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

Answer 5

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

Question 6

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

Answer 6

When CO2 levels become too low, the brain can decrease the respiratory rate in order to raise CO2 levels

Question 7

What are some mxns used in the respiratory system to prevent infection

Answer 7

Immune mxns in the respiratory system include vibrisse in the nares, lysozyme in the mucous membranes, the mucocilliary escalator, macrophages in the lungs, mucosal IgA antibodies, and mast cells

Question 8

What is the chemical equation for the bicarbonate buffer system?

Answer 8

CO2(g)+ H2O (l) –>

Question 9

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

Answer 9

In respiratory failure, ventilation slows, and less CO2 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.

Question 10

what is the opening to the larynx called?

Answer 10

glottis

Question 11

where are the vocal cords located

Answer 11

in the larynx

Question 12

how many vocal cords do we have

Answer 12

2

Question 13

What innate immune mxn exists in the trachea and bronchi?

Answer 13

ciliated epithelial cells that can catch materials that made it past the mucous membrane in the nose and mouth

Question 14

what is the difference between the right and left lung? why does this difference exist?

Answer 14

right lung is bigger than left lung, right has 3 lobes; left has 2. left lung has small indentation which makes it smaller. this is because the heart is on the left side of the body in the thoracic cavity

Question 15

why can the alveoli exchange gas very effectively?

Answer 15

super long surface area ((~100m2) and lots of branching and v tiny size of the alveoli

Question 16

what are pleurae?

Answer 16

membranes that surround the lungs. form the sac against which the lung expand. contains intrapleural space (fluid)

Question 17

why is the pleura impt for breathing?

Answer 17

the pressure differentials that can be created across the pleura ultimately drive breathing
think of half filled balloon and fist analogy, balloon is pleural layers; fist is lung. when fist ((lung) expands on the balloon (pleura), the balloon comes up and surrounds the hand… drives the mxn of breathing ((pressure differentials)
these pressure differentials drive air into the lungs

Question 18

is inhalation an active or passive process?

Answer 18

active

Question 19

what muscles are used to inhale?

Answer 19

diaphragm and external intercostal muscles (muscles between the ribs) to expand thoracic cavity

Question 20

during inhalation, as the diaphram flattens, what happens?

Answer 20

the chest wall expands, the intrathoracic volume (the volume in the chest cavity) increases, and because of Boyle’s law, an increase in intrapleural volume leads to a decrease in intrapleural pressure

Question 21

after inhalation, have low pressure in the intrapleural space. what happens to the pressure in the lungs?

Answer 21

gas in lungs is initially atmostpheric, but after inhalation, it is higher pressure than the gas in the intrapleural space

Question 22

what is the effect of having higher pressure in the lungs than in the intrapleural space?

Answer 22

the lungs will expand into the intrapleural space and the pressure in the lungs will drop and air will be sucked in from a hgher pressure environment– the outside world

Question 23

what is the name of the mechanism that drives inhalation?

Answer 23

negative-pressure breathing

bc the driving force is the lower (relatively negative) pressure in the intrapleural space compared to the lungs)

Question 24

is exhalation an active or passive process

Answer 24

passive

Question 25

how do we exhale

Answer 25

simple relaxation of the external intercostal muscles will reverse inhalation

Question 26

describe the process of exhalation

Answer 26

relac diaphram and external intercostal muscles will decrease V in chest cavity which will increase the pressure in the intrapleural space (Boyles law) so that the pressure in the intrapleural space is higher than the lungs (which are at atmostpheric pressure) so air is pushed out ((exhalation)

Question 27

during active can speed up the process of exhalation by using whihc muscles

Answer 27

inner intercostal muscles and abdominal muscles

-these muscles opposed external intercostal muscles and pull the ribcage down