The human respiratory system

Question 1

where does the respiratory system take place?

Answer 1

thorax

Question 2

step one of breathing -

Answer 2

when we breathe in, air enters in through the nose and mouth

Question 3

step two of breathing -

Answer 3

air travels down the trachea to the lungs, tiny hairs (cilia) help to remove dirt and micro-organisms

Question 4

step three of breathing -

Answer 4

air enters the lungs through the bronchi with branch and divide to form a network of bronchioles

Question 5

step four of breathing -

Answer 5

at the end of the bronchioles are air sacks, with bulges on them called alveoli which are covered in tiny blood capillaries and this is where oxygen and carbon dioxide are exchanged between the blood and the air in the lungs - called gas exchange

Question 6

step one of inhalation -

Answer 6

diaphragm contracts and flattens

Question 7

step two of inhalation -

Answer 7

external intercostal muscles contract, ribs move upwards and outwards

Question 8

step three of inhalation -

Answer 8

causes the volume of the thorax to increase

Question 9

step four of inhalation -

Answer 9

this causes the air pressure in the thorax to decrease

Question 10

step five of inhalation -

Answer 10

this draws air into the lungs

Question 11

step one of exhalation -

Answer 11

diaphragm relaxes, returns to its dome shape when it is pushed up by the liver and stomach meaning that it pushes up on the layer

Question 12

step two of exhalation -

Answer 12

external intercostal muscles relax allowing the ribs to drop back and also presses on the lungs

Question 13

step three of exhalation -

Answer 13

causes the volume of the thorax to decrease

Question 14

step four of exhalation -

Answer 14

cause the air pressure in the thorax to increase

Question 15

step five of exhalation -

Answer 15

this causes air to be pushed out of the lungs

Question 16

why do alveoli have thin permeable walls?

Answer 16

keep the distance over which diffusion of gases takes place, between the air and blood, to a minimum

Question 17

why do alveoli have a moist lining?

Answer 17

this is where the gases dissolve before they diffuse across the cell membrane

Question 18

why and how do alveoli have a large surface area?

Answer 18

there are hundreds of millions of alveoli in a human lung giving it a surface area of around 70m2 for diffusion

Question 19

why do alveoli have a high concentration gradient?

Answer 19

for the gases

Question 20

what is the word equation for anaerobic respiration ?

Answer 20

glucose –> ethanol + carbon dioxide (+some energy)

Question 21

what is the symbol equation for anaerobic respiration?

Answer 21

C6H12O6 –> 2C2H5OH + 2CO2

Question 22

what is the word equation for aerobic respiration?

Answer 22

glucose –> lactic acid (+some energy)

Question 23

what is the symbol equation for aerobic respiration?

Answer 23

C6H12O6 –> 2C3H6O3