Pulmonary Mechanics

Question 1

Define Ventilation

Answer 1

Movement of air in and out of lungs

Question 2

What helps expand the chest cavity?

Which is the main muscle of respiration?

Answer 2

(1) Ribcage and Diaphragm

(2) Diaphragm

Question 3

Name the two sides of the pleural cavity and where they are located

Answer 3

First is the parietal pleura, outside (touches chest cavity), next is the visceral pleura, inside (touches the lungs)

Question 4

How does the diaphragm help with ventilation?

Answer 4

Pulls on parietal pleura, generates neg. pressure between parietal and visceral, that then pulls on the visceral pleura, which pulls on lungs and expands them. Neg. pressure is in lung tissue and sucks in the air.

Question 5

What is a pneumothorax?

Answer 5

When a lung collapses under its own weight because air is leaking in the pleural cavity

Question 6

Define Tension Pneumothorax

Answer 6

When there is a whole in the pleural cavity, the lungs but NOT the chest cavity

Question 7

Where does respiratory system starts?

Answer 7

From oral and nasal cavities. Oral mucosa warms air and helps filter out matter

Question 8

Respiratory pathway

Answer 8

Oral/Nasal Cavity&raquo_space; Pharynx&raquo_space; Glottis&raquo_space; Larynx&raquo_space; Trachea&raquo_space; Mainstem Bronchi&raquo_space; Bronchiole&raquo_space; Alveolus

Question 9

What causes positive pressure?

What does it prevent?

Answer 9

(1) Closing of the vocal cords

(2) Collapsing of lungs

Question 10

Type I pneumocytes

Answer 10

Make up wall of alveoli. Across these cells is where diffusion occurs so O2 and CO2 get in & out of blood stream.

Question 11

Type II pnemocytes

Answer 11

Secrete surfactin to help decrease surface tension

Question 12

T or F. Type II cells are larger than Type I

Answer 12

TRUE

Question 13

Define Atelectasis

Answer 13

is collapse of part of the lung

in response air gets shunted to other alveoli that are not collapsed

Question 14

Define Alveolar Ventilation

Answer 14

Movement of oxygen and carbon dioxide in and out of the alveoli

Question 15

Define Elasticity

Answer 15

object resists and recovers from deformation produced by force

Question 16

Elasticity equation and units

Answer 16

(E) = Pressure/Volume = cmH2O/liter

Question 17

Define Compliance

Answer 17

deformation per unit force applied

Question 18

Compliance equation and units

Answer 18

(C) = Volume/Pressure = liter/cmH2O

Question 19

What is the numerical value of positive pressure during spontaneous ventilation?

Answer 19

about 5 cmH2O

Question 20

T or F. large alveoli has higher surface tension.

Answer 20

False. smaller alveoli have higher surface tension. (think of Leplace’s Law)

Question 21

Define Laplace’s Law

Answer 21

The pressure inside a bubble exceeds the pressure outside the bubble by twice the surface tension, divided by the radius. In other words, the smaller a bubble, the more the pressure inside it exceeds the pressure on the outside.

Question 22

T or F. Lungs natural tendency is to collapse and the thoracic cavity natural tendency is to expand

Answer 22

TRUE

Question 23

Accessory Muscles in Expiration

Answer 23

abdominal, cervical strap, sternoclediomastoid, neck, and intervertebral muscles

Question 24

Where is Respiratory Center of the brain located?

Answer 24

Medulla Oblongata

Question 25

What part of the brain establishes respiratory rhythm?

Answer 25

Brainstem and Pons

Question 26

What part of the medulla is INSPIRATORY?

Answer 26

Ventral Respiratory Group

Question 27

What part of the medulla is EXPIRATORY

Answer 27

Dorsal Respiratory Group

Question 28

T or F. Aortic bodies of chemoreceptors have a ventilatory effect

Answer 28

FALSE. Carotid Bodies have a ventilatory effect and Aortic Bodies have a Circulatory effect