6.4 Respiratory system

Question 1

Blame the need for ventilation system

Answer 1

Human bodies too thick

• only outside cells exposed to oxygen, other too far to have oxygen diffuse within it
• cant just move around to circulate
• continuous breathing ensures that concentration of respiratory gases in lungs encourages diffusion (lungs need higher concentration of oxygen to diffuse into capillary bed, if no ventilation system won’t happen)

-need ventilation system to move enough oxygen around our body so that we don’t die

Question 2

Draw and label a diagram of the ventilation system including trachea, lungs, bronchi, bronchioles and alveoli

Answer 2

Do it

Question 3

By the mechanisms of ventilation of the lungs in terms of volume and pressure changes caused by the internal and extra intercostal muscles, the diaphragm and abominable muscles.

Answer 3

-at resting: pressure inside lungs = pressures outside
breathe in:
-diaphragm contacts
-intercostal muscles (external contract, internal relax) and adnominal muscles contact = rib cage is raised, volume increases in lungs, pressure deceases
-p inside p outside, air passively flows out
-receptors send signals to start contractions, mechanisms to breathe in

Question 4

Describe the features of alveoli that adapting to gas exchange

Answer 4

1. Spherical shape of alveoli: provides a large surface area of respiration respiratory gases to diffuse through because I sphere is the shape of the highest surface area to volume ratio of
2. millions of alveoli= increase surface area for gas exchange
3. 1 cell thick, flattened cells, Thin = prevents respiratory gases from having to move through more cell layers, easier diffusion
4. Very small: short distance for diffusion
5. Moist inner lining: allows for efficient diffusion
6. surrounded by capillaries: easy to diffuse into blood, doesn’t have to diffuse far

Question 5

Distinguish between ventilation, gas exchange and cell respiration.

Answer 5

Ventilation: exchange of gases between lungs and outside air

Gas exchange: exchange of gases between alveoli and capillaries -external respiration
& capillaries and body cells -internal respiration

cell respiration: exchange of gases and mitochondria that produce energy 02 is a reacted and CO2 is a product