Ch2 Pulmonary Anotomy and physiology

Question 1

Respiration

Answer 1

movement of gas molecules across cell membranes.

Question 2

Ventilation

Answer 2

exchange of gas between lungs and the atmosphere.

Question 3

What are the Four functional events of Cellular Respiration?

Answer 3

Ventilation
Distribution
Perfusion
Transport

Question 4

The cyclic movement of the diaphragm and the structures of the thorax that results in the bulk movement of gases in and out of the lungs refers to what?

Answer 4

Ventilation

Question 5

What is the primary ventilator muscle?

Answer 5

Diaphragm

Question 6

Name the Accessory muscles of inspiration that cause the thorax to rise?

Answer 6

Scalene
trapezius
pectorlis,

Question 7

Name the Accessory muscles of expiration?

Answer 7

Intercostals= pull ribs downward

abdominals = push diaphragm up

Question 8

How many lobes does the Right lung have?

Answer 8

3

Question 9

How many lobes does the Left lung have?

Answer 9

2

Question 10

The mediastinal surface of each lung contains and area through which bronchi, pulmonary blood vessels, lymphatic vessels, and nerves enter and exit. What is it called?

Answer 10

Hilum

Question 11

What lines the walls of the thoracic cavity?

Answer 11

Parietal pleura

Question 12

What lines the outside of the lungs?

Answer 12

Visceral pleura

Question 13

Pleural cavity?

Answer 13

Space between the parietal covered thoracic cavity and the visceral pleura covered lungs.

Question 14

During spontaneous breathing what happens?

Answer 14

Negative intra-thoracic pressure draws air into the lung, and positive pressure blows it out.

Question 15

Pressure cycled mechanical ventilation

Answer 15

Delivers air into airway until a set pressure is achieved.

Question 16

Volume cycled mechanical ventilation.

Answer 16

Delivers air into airway until a set volume is achieved.

Question 17

Time-cycled mechanical ventilation.

Answer 17

Delivers a volume of gas over a pre- set time.

Question 18

Describe the mechanics of Inspiration during ventilation?

Answer 18

1. > External intercostals contract which pull ribs upward and forward
2. > Diaphragm contracts, descends and flatten
3. > Lungs adhere to chest wall so the net result is a vacuum and air is drawn in
4. > The negative intrathoracic pressure 755-757 mm Hg and air is drawn into the lungs. 5. > This also creates a vacuum for venous blood, which ↑ venous pressure.

Question 19

Describe the mechanics of expiration during ventilation?

Answer 19

1.> Intercostals relax, diaphragm relaxes = dimensions are reduced resulting in > atmospheric pressure= exhalation.

Question 20

CNS sensory neurons called “chemoreceptors” are located where?

What do they respond to ?

Answer 20

In or near the medulla oblongata in the CNS.

They respond to changes in H+ concentration or Pco2, or both in the CSF.

Question 21

What does pCO2 stand for?

Answer 21

Partial Pressure of Carbon Dioxide

Question 22

H+ ions are powerful stimulants to CNS chemoreceptors, but can not cross the blood: brain barrier. CO2 however, is highly permeable, so blood levels will quickly equilibrate in the CSF.
CO2 + H2O → H2CO3 → H+ + HCO3.

Answer 22

An increase in CO2 would also increase the H+ concentration which means a decrease in PH which makes a person acidotic.

Question 23

Locations of Peripheral Nervous System Chemoreceptors?

Answer 23

Located in carotid (carotid bodies) and aortic arch. They transmit excitatory signals to the central respiratory center in the brainstem in response to low arterial oxygenation. (PaO2 60 - 30 mmHg)

Question 24

Normal PaO2 ?

Answer 24

90-100 mmHg

Question 25

Elevated PCO2 are characteristic of ?

Answer 25

COPD patients