UNIT 11- RESPIRATORY SYSTEM

Question 1

In humans the right lung is made up of _____ lobes, whereas the left lung is made up of _____ lobes

Answer 1

3, 2

Question 2

Describe the passage of air through the lungs

Answer 2

air flows through pharynx—> larynx —> trachea—> left and right bronchi—-> terminal bronchioles—> respiratory bronchioles—> alveolar ducts + sacs

Question 3

What is the role of alveolar ducts and sacs?

Answer 3

moisten and cleanse air taken in and transfer to gas exchanging portion

Question 4

Gas exchange occurs through _______. Why does one human lung have up to 300 million of these structures?

Answer 4

gas exchange occurs through alveoli. These provide a large surface area for gas diffusion- gases from air in alveoli are exchanged with gases in pulmonary capillary blood

Question 5

What are the 2 types of alveolar cells and what are their associated functions? Which of these cells is an important factor in regulating gas exchange based on its thickness?

Answer 5

Type I alveolar cells- gas exchange
Type II alveolar cells- secretion of pulmonary surfactant and reabsorption of water and sodium
- Type I cells are an important factor in regulating gas exchange based on the thickness of these cells

Question 6

What is the role of the pulmonary surfactant?

Answer 6

reduces effort in breathing and help prevent collapse of alveoli. Reduce hydrogens between water molecules thereby reducing surface tension that holds membranes of different alveoli together

Question 7

What are the 2 zones of air passages and what are their associated functions?

Answer 7

1. Respiratory zone- gas exchange occurs, includes bronchioles and alveoli
2. Conducting zone- all structures through which air passes before reaching respiratory zone

Question 8

Describe the effects of inhalation on thoracic volume, the diaphragm, external intercostal muscles and alveolar pressure

Answer 8

Increase thoracic volume
lowers diaphragm
decrease alveolar pressure
contraction of external intercostal muscles

Question 9

Describe the effects of exhalation on thoracic volume, the diaphragm, external intercostal muscles and alveolar pressure

Answer 9

decrease thoracic volume
raises diaphragm
increase alveolar pressure
expansion of external intercostal muscles

Question 10

Collapse of alveoli occurs when pressure inside smaller alveolar sac is ____________ than pressure in larger alveolar sac. What mechanism prevents this by minimizing the difference in alveolar pressure?

Answer 10

Collapse of alveoli occurs when pressure inside smaller alveolar sac is LARGER than pressure in larger alveolar sac
Forces air in small sac to force its way into larger sac
surfactant prevents this

Question 11

How is oxygen bound to hemoglobin?

Answer 11

Hemoglobin has 4 iron containing heme groups- oxygen attaches to iron atom and is carried to tissues and cells

Question 12

_____________ temp, _____________ pH, _____________ CO2 all reduce hemoglobins affinity for O2

Answer 12

INCREASED temp, DECREASED pH, INCREASED CO2 all reduce hemoglobins affinity for O2

Question 13

What does decreased pH do to binding of oxygen?

Answer 13

changes shape of oxygen binding sites of hemoglobin

Question 14

What does increased temp do to binding of oxygen?

Answer 14

prevents bonds from forming and break bonds that have already been made

Question 15

What does increased CO2 do to binding of oxygen?

Answer 15

CO2 can bond to sites where O2 would normally bind

Question 16

What are the 3 ways CO2 is transported in blood?

Answer 16

1. CO2 is blood is dissolved molecular CO2
2. CO2 reacts with NH2 groups of hemoglobin and other proteins to form carb amino compounds
3. Most CO2 is transported in form of bicarbonate

Question 17

Respiration ______ and respiration ______ work to increase pH when pH is low by __________

Answer 17

Respiration RATE and respiration DEPTH work to increase pH when pH is low by DECREASING H+

Question 18

Increase breathing-> ________ CO2 blood and _________pH causing ___________ in bicarbonate

Answer 18

Increase breathin- >DECREASE CO2 blood and INCREASE pH causing DERCEASE in bicarbonate

Question 19

Medullary respiratory center contains ________ and _______ neurons

Answer 19

inspiratory and expiratory neurons

Question 20

Inspiration is periodically interrupted by inhibition from ______________

Answer 20

pneumotaxic centre

Question 21

Duration of expiration may be extended if ____________________ receptors are very active

Answer 21

pulmonary stretch receptors

Question 22

What receptors are responsible for ventilation?
What receptors are responsible for maintaining lung expansion and size of airway?

Answer 22

chemoreceptors are responsible for ventilation
mechanoreceptors are responsible for maintaining lung expansion and size of airway

Question 23

Chemoreceptors are _______ sensitive to high PCO2 than low O2

Answer 23

MORE

Question 24

What is the Hering Breuer reflex?

Answer 24

prevents over inflation of lung through pulmonary stretch receptors during heavy exercise. Inhibits respiratory control centres

Question 25

With increasing altitude there is ____________ in PO2

Question 26

High altitude _________ PO2, ____________ breathing, __________PCO2 to slow breathing and therefore ___________ PO2. Causes _____________ otherwise known as intermittent breathing and hypoxia

Answer 26

High altitude DECREASES PO2, INCREASES breathing, DECREASES PCO2 to slow breathing and therefore DECREASES PO2 (LARGE DECREASE IN PO2) Causes CHEYNE STOKES otherwise known as intermittent breathing and hypoxia

Question 27

When animal is in area of hypoxia for long period of time blood and CSF levels are…

Answer 27

brought back down to NORMAL by release of bicarbonate

Question 28

What is altitude sickness?

Answer 28

athletes who exercise at high altitudes experience decreased atmospheric pressure therefore every breath inhaled has LESS O2 available

Question 29

What is the difference between acute mountain sickness (AMS) and high altitude pulmonary edema (HAPE)?

Answer 29

AMS- body overcompensates for decreased oxygen by trying to send as much blood as possible to the brain- capillary leakage into brain causes swelling

HAPE- increased blood flow as a result of high altitude- excessive BP causes fluid to leak from blood vessels into alveoli sacs of lungs. Fluid in lungs blocks oxygen-blood interface- body tries to compensate by increasing BP but that forces more fluid into lungs