Respiratory System

Question 1

Where are the lungs housed?

Answer 1

in pleural sac in rib cage

Question 2

What is the diaphragm?

Answer 2

The muscle responsible for inhalation and exhalation

Question 3

Describe how inhalation occurs

Answer 3

Diaphragm contracts, expansion in the interpleural space and an increase in negative pressure occurs, therefore air enters the lungs

Question 4

Describe how exhalation occurs

Answer 4

Diaphragm relaxes, decrease in interpleural space, positive pressure occurs and so air exits the lungs

Question 5

What keeps the trachea open?

Answer 5

Cartilage rings on the outside which are for protection

Question 6

Name the purposes of bronchi and cilia. When are cilia non functional?

Answer 6

1) Produce mucus via goblet cells to trap dirt particles and microorganisms
2) continuously cleared by cilia to pharynx and then swallowed
3) Cilia are non function in smokers

Question 7

What does the bronchi branch to become?

Answer 7

Bronchioles (no cartilage rings)
which branch to 
alveolar ducts 
which branch to
alveoli

Question 8

Number of alveoli and surface area?

Answer 8

about 500 million

70m(squared)

Question 9

What do alveoli form?

Answer 9

Grape-like clusters called alveolar sacs

Question 10

What are alveolar macrophages?

Answer 10

Phagocytic cells used for defence

Question 11

How many alveolar macrophages are there?

Answer 11

12-14 in each alveoli

so 12-14 x 500million

Question 12

What tends to accumulate in alveolar macrophages?

Answer 12

Basic drugs and macrolides

Question 13

Continuous drug accumulation in AMs can cause

Answer 13

Phospholipidosis

Question 14

When is the efficiency of bacterial phagocytosis in the lungs compromised?

Answer 14

In smokers and COPD patients

Question 15

Diffusion is faster or slower in water?

Answer 15

Slower

Question 16

Diffusion is directly proportional to?

Answer 16

surface area and membrane permeability

Question 17

Diffusion also depends on..

Answer 17

the magnitude of the concentration gradient

Question 18

What is carbonic anhydrase?

Answer 18

Fastest enzyme known. Important for CO2 elimination.

Question 19

How is CO2 mostly transported?

Answer 19

By the blood in the form of HCO3-

happens via carbonic anhydrase

Question 20

Name the first three steps of gas exchange (8 total)

Answer 20

1) Inhalation
2) Diffusion of 02 from alveoli to lung capillary
3) O2 diffuses to red blood cell and binds to haemoglobin

Question 21

What happens in steps 4-8 of gas exchange?

After the red blood cell has O2 binded to its haemoglobin

Answer 21

4) O2 leaves haemoglobin and and diffuses into a tissue from a systemic capillary
5) CO2 diffuses from tissues to capillaries and is converted to HCO3- in erythrocytes
6) HCO3- travels in plasma and is then made to CO2
7) Diffusion of CO2 from capillary wall into alveoli
8) Exhalation

Question 22

Describe the chosen treatment for respiratory disease such as ashtma and COPD

Answer 22

Dry powder inhalers

Metered dose inhalers- salbutamol and salmeterol

Question 23

What does salmeterol do?

Answer 23

Treat the constriction of the airways

Question 24

Name the two components of (brand name) Seretide

Answer 24

Salmeterol and Fluticasone

Question 25

What is Fluticasone?

Answer 25

A corticosteroid

Question 26

Advantages of pulmonary absorption?

Answer 26

Rapid due to large surface area of lungs (instantaneous absorption)
Avoids first pass metabolism
Local application at the site of action

Question 27

Disadvantages of pulmonary absorption?

Answer 27

Commonly only 2-10% of dose is deposited in the lungs. 90% of the dose is swallowed.