Intro to Resp

Question 1

What defines pressure

Answer 1

force/unit area exerted on a surface by gas next to it

Question 2

What’s the kinetic theory of gases

Answer 2

the more frequent and harder the collisions the higher the pressure

Question 3

What does Boyle’s law tell us?

How can we relate Boyle’s law to the respiratory system?

Answer 3

Pressure is inversely proportional to volume.

When bronchioles and alveoli expand the volume increases and pressure decreases: generating a pressure gradient. Since pressure moves from high –> low, air is drawn into the alveoli

Question 4

What is the partial pressure of O2 in alveoli?

Answer 4

13.3 kPa

Question 5

What does Charle’s Law tell us?

Answer 5

Absolute temperature is proportional pressure.

Temperature increases velocity which increases collision which increases pressure!

Question 6

What generates saturated vapour pressure?

Which factor does it depend on?

Answer 6

Moles leaving water and going to gas exert this pressure, depends on temperature

Question 7

What is the universal gas law?

Answer 7

Pressure X Volume = R (Ideal gas constant) X Temperature

Question 8

what defines ‘tension’

Answer 8

The pressure exerted as gas molecules enter water

Question 9

What 2 factors are equal at equilibrium? What does this tell us?

Answer 9

Partial pressure and tension of gas in a mixture, should tell you how readily the gas will leave the liquid.

Question 10

What determines the amount of gas that enters a liquid? (and establishes a tension)

Answer 10

Solubility of the gas

Question 11

How much oxygen should 5L of blood pick up per min at rest. What feature of the airways ensures this is able to happen?

Answer 11

12 mmol, large SA of small compartments (alveoli) surrounded by capillaries

Question 12

How many lobes are in the R and L lung?

Answer 12

3 in the right, 2 in the left

Question 13

Name a characteristic difference between bronchi and bronchioles

Answer 13

Bronchi have cartilage in their walls, bronchioles have smooth muscle

Question 14

What is the typical pulmonary arterial pressure?

Why does no fluid form in the lungs under normal circumstances?

Answer 14

14-18 mmHg
No fluid forms (without the presence of disease) as there is low pressure and low resistance in the pulmonary circulation

Question 15

Explain Ventilation Perfusion Matching

Answer 15

Matching the amount of air that reaches the alveoli with a sufficient amount of blood that carries it away

Question 16

What two forces interact to balance the amount of fluid that stays and leaves the vessels?

Answer 16

Hydrostatic and Oncotic pressure

Question 17

Name the ‘respiratory’ and ‘conducting’ components of the resp system

Answer 17

Conducting:

1. Upper resp tract: mouth/nose, larynx
2. Lower resp tract: trachea, lungs, bronchi, bronchioles and terminal bronchioles

Respiratory: alveolar ducts and alveoli

Question 18

Which epithelia are specific to the nose? What’s their function?

Answer 18

Olfactory epithelia: have olfactory neurones that are able to sense smell

Question 19

At what point in the resp tract do goblet cells cease? What replaces them and what is their function?

Answer 19

Present until the terminal bronchioles, replaced by Clara cells; thin the mucus and have immune functions

Question 20

What is the function of the oropharynx?

Answer 20

A passageway under the nasopharynx for food moving from mouth - esophagus and air moving to and from the nasal cavity

Question 21

What type of epithelium lines most of the resp tract?

Answer 21

Pseudostratified ciliated columnar

Question 22

What are 3 things the larynx do?

Answer 22

1. Vocal cords
2. Protect airways from choking on material in the throat
3. Regulates flow of air into lungs

Question 23

What happens to the epithelium as the diameter of the resp tract decreases?

Answer 23

Columnar epithelium becomes more cuboidal

Question 24

What are the 3 types of cells found in the alveoli? What are their functions?

Answer 24

1. Simple squamous: provide a short barrier for gas diffusion
2. Cuboidal surfactant secreting cells: surfactant decreases the surface tension so alveoli can inflate easier
3. Macrophages: scavenge small debris that reaches the alveoli