chapter 8

Question 1

inspiration, define and explain

Answer 1

(inhalation) : process of taking air into the lungs
- diaphragm contracts, chest cavity goes down while intercostal muscles contract, rib cage goes up and out
- lung volume increases
- air flows from high to low pressure in lungs

Question 2

expirations, define and explain

Answer 2

(exhalation) : process of breathing out
- diaphragm relaxes, pushing up chest cavity while rib cage moves down and in
- lung volume decreases
- air flows from high to low pressure outside

Question 3

why are the lungs suited to gas exchange? (5 of them)

Answer 3

• alveoli provide large internal surface area so large amounts of gas can be exchanged quickly
• alveolus are well supplied with blood vessels so the blood is close to the air in the alveolus so the blood flow maintains the conc gradient

-membrane of the alveolus is very thin so gas molecules don’t have far to travel when moving in/out of the blood
lungs

• lungs are deep inside body to prevent excess evaporation of fluid covering the respiratory surfaces. The membrane must be covered in moisture because gas can only diffuse in/out of blood when dissolved in fluid
• lung volume can be changed by respiratory muscles so air flows in/out. Constant changing of air in the alveoli ensures a difference in concentrations O2/CO2 in air/blood.

Question 4

how is the conc gradient for O2 and CO2 maintained?

Answer 4

• through the movement of air and blood

- blood through

Question 5

what’s ventilation?

Answer 5

process by which air is moved into and out of the lungs (flow from high to low pressure)

Question 6

what’s emphysema

Answer 6

particles damage alveoli>loose elasticity>lungs are constantly inflated>breathing is difficult

Question 7

what is lung cancer

Answer 7

a tumour (mass of cells dividing uncontrollably)>excessive mucus production>smokers cough

Question 8

what is a lung infection?

Answer 8

e. g. pneumonia=caused by bacteria, viruses, fungi

- inflammation>secretion of fluid/mucus>reduced amount of air space>breathing difficulty

Question 9

what is asthma?

Answer 9

an allergic response to foreign substances> bronchioles go into spasm>narrowing of air passages>breathing difficulty

Question 10

in the respiratory system what does the larynx and trachea do?

Answer 10

larynx is the organ of voice

trachea carries air to and from lungs, cilia moves mucus and trapped particles

Question 11

in respiratory system what are the bronchi, bronchioles and alveoli?

Answer 11

bronchi divide into secondary and tertiary bronchi
bronchioles are fine tubes with walls of smooth muscle
alveoli are groups of air sacs, they’re well supplied with blood capillaries for the exchange of 02 and C02

Question 12

whats the difference between the ribs and the intercostal muscles?

Answer 12

ribs=framework for the chest

intercostal muscles=move rib cage to increase/decrease volume of chest cavity/lungs

Question 13

where is the pleura fluid located and what does it do?

Answer 13

on the inside of the lungs

holds lungs against the inside of the chest wall and allows them to slide along the wall when breathing