The Respiratory System

Question 1

Where are the lungs located?

Answer 1

thoracic cavity

Question 2

What is the pathway that the air goes through in the respiratory system?

Answer 2

(1) Air enters through the external nares in the the nose
(2) Then it goes into the pharynx (food and air) and larynx (only air)
(3) Then it goes into the cartilaginous trachea and into one of two mainstem bronchi
(4) Then the air goes into bronchioles and then alveoli

Question 3

What is the larynx?

Answer 3

the pathway below the pharynx that is just for air that leads into the lungs

Question 4

What keeps food out of the larynx?

Answer 4

the epiglottis

Question 5

What is surfactant?

Answer 5

a detergent that aveoli are coated in that lowers surface tension and keeps the aveoli from collapsing in on themselves

Question 6

What is the pleurae?

Answer 6

membranes that surround the lungs and form a closed sac

Question 7

What is the diaphragm?

Answer 7

a thin, muscular structure that divides the thoracic cavity from the abdominal cavity

Question 8

What is intrapleural space?

Answer 8

the space between parietal and visceral pleaura and is filled with a thin layer of fluid

Question 9

What is external intercostal muscle?

Answer 9

one of the layers of the muscle between the ribs to expand the thoracic cavity

Question 10

How does inhalation work?

Answer 10

(1) Diaphragm flattens and the chest wall expands. The intrathoracic volume increases.
(2) Intrapleural volume increases. Intrapleural pressure decreases.
(3) Lungs expand into low pressure intrapleural space and its volume decreases.
(4) Air moves from high pressure outside space into the low pressure lungs

Question 11

How does exhalation work?

Answer 11

(1) Diaphragm relaxes (or internal intercostal muscles are used to push it up) and the chest wall and lungs contract due to intrinsic elastic quality
(2) Volume in intrapleural decreases and pressure increases
(3) The pressure in intrapleural space/lungs is higher than outside
(4) Air is pushed out

Question 12

What is a spirometer?

Answer 12

an instrument that a patient blows into and can measure the capacity of the lungs

Question 13

What is TLC?

Answer 13

Total Lung Capacity - the maximum volume of air int he lungs when one inhales completely; usually around 6 or 7 liters

Question 14

What is RV?

Answer 14

Residual Volume - the volume of air remaining in the lungs when one exhales completely

Question 15

What is VC?

Answer 15

Vital Capacity - the difference between the minimum and maximum volume of air in the lungs (TLC-RV)

Question 16

What is ERV?

Answer 16

Expiratory Reserve Volume - the volume of additional air that can be forcibly exhaled after a normal exhalation

Question 17

What is IRV?

Answer 17

Inspiratory Reserve Volume - the volume of additional air that can be forcibly inhaled after a normal inhalation

Question 18

What is the ventilation center?

Answer 18

a collection of neurons in the medulla oblongata that fire rhythmically to cause regular contraction of respiratory muscles

Question 19

What is too much carbon dioxide in the blood called?

Answer 19

hypercarbia/hypercapnia

Question 20

What is too low oxygen in the blood called?

Answer 20

hypoxemia

Question 21

What is the relationship between VC, IRV, ERV and TV?

Answer 21

VC = IRV + ERV + TV

Question 22

What are pulmonary arteries?

Answer 22

bring deoxygenated blood from the right ventricle to capillaries (inside the lungs)

Question 23

What are pulmonary veins?

Answer 23

bring oxygenated blood from the lungs to the left atrium of the heart (inside the lungs)

Question 24

How is the respiratory system used for thermoregulation?

Answer 24

Capillaries expand, more blood goes through, and more heat is released - cooling the body down OR
Capillaries restrict, less blood goes through, and heat is conserved - heating/maintaining the body

Question 25

What are mast cells?

Answer 25

cells that have preformed antibodies on their surfaces, when pathogens attach the cell releases inflammatory chemicals into the surrounding area

Question 26

How does the respiratory system deal with acidemia?

Answer 26

H+ increases —> CO2 increases —> respiratory rate increases —> CO2 concentration decreases —> H+ decreases —> pH decreases

Question 27

How does the respiratory system deal with alkalemia?

Answer 27

too basic —> respiratory rate decreases —> CO2 concentration increases —> H+ increases —> pH increases

Question 28

What is the bicarbonate buffer system?

Answer 28

CO2 (g) + H2O (l) H2CO3 (aq) H+ (aq) + HCO3- (aq)

Question 29

Where are the vocal cords?

Answer 29

in the larynx

Question 30

What is the respiratory system’s defense against pathogens?

Answer 30

(1) Nasal Cavity - lined with vibrissae hairs that trap particulates
(2) Lysozymes - attacks gram positive bacteria
(3) Mucus - trapped particulates and cilia in the tract push the mucus upwards (mucociliary escalator)