respiratory system & gaseous transport

Question 1

what are the steps of insperation?

Answer 1

1. rib cage up + out
2. abdomen out as diaphragm is flattened
3. external intercostal muscles contract
4. internal intercostal muscles relax

Question 2

what are the steps of expiration?

Answer 2

1. ribcage down + in
2. abdomen in as diaphragm is pushed up
3. external intercostal muscles relax
4. internal intercostal muscles contract

Question 3

adaptions of alveoli

Answer 3

• large surface area for diffusion
• walls 1cm thick- short diffusion pathway
• Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface.
• Permeable walls - allow gases to pass through.

Question 4

the rate of diffusion is proportional to….

Answer 4

(surface area X difference in concentration) divided by (thickness of surface exchange)

Question 5

the function of erythrocytes

Answer 5

(red blood cell)

transport o2 & co2 around the body

Question 6

features of erythrocytes

Answer 6

• bicon-cave shape: increases surface area and diffusion, and fold to fit through capillaries.
• contains haemoglobin which aids O2 transportation
• no nucleus: more space for heamoglobin
• Iron ion (Fe2+) in heamoglobins haem groups allow O2 to bing reversibly

Question 7

associate meaning

Answer 7

bind with

Question 8

dissociate meaning

Answer 8

ability to bind

Question 9

affinity meaning

Answer 9

ability to bind