Chapter 6 -Respiratory System

Question 1

The inner pleural membrane that surrounds the lungs is called ____________.

Answer 1

Visceral pleura

Question 2

The outer pleural membrane that surrounds the lungs is called __________

Answer 2

Parietal pleura

Question 3

Which division of the nervous system controls the diaphragm?

Answer 3

Somatic nervous system

Question 4

What is the diaphragm?

Answer 4

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

Question 5

What happens when the diaphragm relaxes?

Answer 5

The volume of the thoracic cavity decreases because the chest wall and intrapleural space is contracted. This causes the pressure of the intrapleural space to increase. This causes the air from the lungs (higher pressure) to rush out into the atmosphere (lower pressure) through a process called exhalation.

Question 6

What happens when the diaphragm contracts (flattens)?

Answer 6

The thoracic cavity expands which creates a decrease in pressure in the lungs, which causes air from the atmosphere (higher pressure) to rush into the lungs (lower pressure).

Question 7

What is surfactant?

Answer 7

It is a substance that coats the alveoli which allows lower surface tension and prevents the alveoli from collapsing on itself during exhalation.

Question 8

Movement of air through the respiratory systems

Answer 8

Nares, nasal cavity, pharynx, epiglottis, larynx, trachea, bronchi, bronchioles, alveoli

Question 9

What is the residual volume?

Answer 9

It is the volume of gas remaining in the lungs after a maximum exhalation. This is the volume of air that is always present in your lungs.

Question 10

What is Total lung capacity (TLC)?

Answer 10

It is the total amount of air in the lungs after a maximum inhalation. This includes the residual volume.

Question 11

What is vital capacity (VC)?

Answer 11

This is the maximum volume of air that can be exhaled after a maximum inhalation. You can calculate it by doing (TLC — RV).

Question 12

What is inspiratory reserve volume?

Answer 12

It is the additional maximum volume of air that can be forcefully inhaled after normal inhalation.

Question 13

What is expiratory reserve volume?

Answer 13

It is the additional maximum volume of air that can be forcefully exhaled after a normal exhalation.

Question 14

What is tidal volume (TV)?

Answer 14

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

Question 15

What are some of the main functions of the lungs?

Answer 15

Gas exchange, protection against invaders trying to access the bloodstream, controlling blood pH

Question 16

The diaphragm moves _________ during inhalation and ________ during exhalation.

Answer 16

Down (contracted), up (relaxed)

Question 17

If there is too much acidity in the blood, how do the lungs compensate for this?

Answer 17

The respiratory rate increases, which causes more carbon dioxide to be released and allows for the blood pH to increase.

Question 18

What is the function of capillaries?

Answer 18

They are tiny blood vessels that play a role in the exchange of oxygen and carbon dioxide at the lungs. They also deliver nutrients and remove waste from the bloodstream and tissues (through diffusion). They act as a bridge.

Question 19

Describe the structure of a hemoglobin protein.

Answer 19

It is a quaternary protein made up of four subunits (two alpha subunits and two beta subunits). Each subunit has an Fe containing heme group which holds 1 O2 molecule.

Question 20

At 100% saturation how many oxygen atoms can 1 hemoglobin molecule carry?

Answer 20

8 Oxygen atoms (4 O2 molecules)

Question 21

What is the driving force for gas exchange at the alveoli?

Answer 21

It is the partial pressure of the two gases. The partial pressure of CO2 is high in the incoming deoxygenated blood which allows for diffusion across the alveolar membrane. The partial pressure of O2 is greater in the alveoli, which allows for oxygen to diffuse down the capillaries into the blood that is destined to go back to the heart.

Question 22

What is the role of the enzyme lysozyme in the nasal cavity?

Answer 22

It is an enzyme, which is able to fight of potential bacteria. It attacks the peptidoglycan wall of gram-positive bacteria.

Question 23

What kind of immune cells are located in the lungs (specifically alveoli)?

Answer 23

Macrophages which are able to engulf and digest pathogens, IgA antibodies, and mast cells which release inflammatory chemicals to promote an immune response.

Question 24

Oxygenated blood returns to the left atrium via ________.

Answer 24

Pulmonary veins

Question 25

The ________________ bring deoxygenated blood to the capillaries for gas exchange.

Answer 25

Pulmonary arteries

Question 26

What happened to hemoglobin saturation at the partial pressure of oxygen increases?

Answer 26

Hemoglobin saturation increases as well, however there is a sigmoidal relationship, because the curve eventually levels off as all of the oxygen binding sites are saturated.

Question 27

In the oxygen hemoglobin disassociation curve, if there is a shift to the right, how does this affect hemoglobin’s affinity for oxygen?

Answer 27

A shift to the right with mean that hemoglobin affinity for oxygen decreases, thus decreasing the hemoglobin saturation.

Question 28

Which factors shift the oxygen, hemoglobin dissociation curve to the right?

Answer 28

Increased temperature, increased CO2, increased proton concentration in blood, increased 2,3 DPG (diglycerol phosphate)

Question 29

On the oxygen hemoglobin dissociation curve, if the curve is shifted to left, how is hemoglobin affinity for oxygen impacted?

Answer 29

The affinity of hemoglobin for oxygen increases, which increases the hemoglobin saturation at the same partial pressure.

Question 30

On the oxygen hemoglobin dissociation drive, which part of the curve represents the partial pressure of oxygen at the lungs?

Answer 30

The part of the curve at the top that is less steep because the hemoglobin affinity for oxygen is high, and the partial pressure of oxygen is high at the lungs.

Question 31

On the oxygen hemoglobin dissociation curve, which part of the curve represents the partial pressure of oxygen at the periphery (tissues)?

Answer 31

The bottom part of the curve where the slope is steep, it has lower hemoglobin affinity for oxygen. This allows for oxygen to dissociate and supply the tissue with oxygenated blood.

Question 32

Which factor can greatly increase hemoglobin affinity for oxygen (so much that it can cause almost 100% saturation for a long period of time resulting in tissue death)?

Answer 32

Carbon monoxide, it greatly increases hemoglobin binding affinity to oxygen which doesn’t allow oxygen to dissociate and causes deprivation of oxygen to the tissues.

Question 33

On the oxygen, hemoglobin, disassociation curve, if the curve is shifted to the right, how does this affect the hemoglobin affinity for oxygen?

Answer 33

The hemoglobin affinity for oxygen decreases which allows for more oxygen to be delivered to peripheral tissues.

Question 34

Which factors shift the oxygen hemoglobin dissociation curve to the left?

Answer 34

Decreased CO2, decreased temperature, decreased DPG, decreased H+ concentration

Question 35

Carbon dioxide travels in the blood in the form of

Answer 35

Bicarbonate (HCO3)

Question 36

What would happen to the pH of the blood (short-term) if the pulmonary artery were blocked?

Answer 36

The pH of the blood would become more acidic, since deoxygenated blood would not be able to reach the lungs for gas exchange.

Question 37

What would happen to the blood pH (short term) if the pulmonary veins were blocked?

Answer 37

The blood pH would become more basic because the individual would start to hyperventilate due to low oxygen supply to the organs and tissues. This would cause excess release of CO2 and metabolic alkalosis.

Question 38

Bicarbonate buffer system equation

Answer 38

CO2 + H2O —> H2CO3 —> HCO3- + H+

Question 39

What is the function of surfactant?

Answer 39

A mixture of phospholipids and lipoproteins that work to reduce the surface tension that exists between the alveoli tissue and the air found within the alveoli