module 3: specialised exchange surfaces

Question 1

size of a small animals sa:vol

Answer 1

high

Question 2

why do large organisms need an exchange surface

Answer 2

diffusion too slow
cells deep within body so big distance to travel
low sa:vol
high metabolic rate so use more oxygen and glucose

Question 3

how are root hair cells specialised

Answer 3

hair like
large sa to increase rate of absorption of water and mineral ions from soil

Question 4

how are alveoli specialised

Answer 4

good blood supply to maintain conc gradient
single cell thick so short diffusion pathway
moist to trap oxygen

Question 5

goblet cells

Answer 5

secrete mucus which traps microorganisms and dust particles in inhaled air

Question 6

cilia

Answer 6

beat the mucus
move sit away from lungs

Question 7

elastic fibres

Answer 7

in walls or trachea, bronchi, bronchioles and alveoli
stretch when inhaled air and recoil to push air out on exhale

Question 8

smooth muscle

Answer 8

walls of trachea, bronchi, bronchioles
diameter control
tubes widen when its relaxes so there is less resistance to air flow

Question 9

rings of cartilage

Answer 9

walls of trachea and bronchi to provide support
strong but flexible to stop collapse

Question 10

inspiration

Answer 10

1- external intercostal muscles contract and diaphragm contracts
2- ribcage up and out and diaphragm flat
3- thorax volume increases so pressure decreases
4- causes air to flow into lungs

Question 11

expiration

Answer 11

1- external intercostal muscles relax and diaphragm relaxes
2- ribcage moves in and down and diaphragm moves up
3- thorax volume decreases so pressure increased
4- air forced out f lungs

Question 12

tidal volume

Answer 12

volume of air in each normal breath

Question 13

vital capacity

Answer 13

maximum volume of air that can be breathed in or out

Question 14

residual volume

Answer 14

volume of air left over in the lungs after rexhaling

Question 15

what does a spirometer show

Answer 15

tidal volume, vital capacity, breathing rate and oxygen uptake

Question 16

how does a spirometer work

Answer 16

has oxygen filled chamber with moveable lid attached to breathing tube
as person breathes lid moves up and down
movement’s recoded by pen attached to lid that writes on a rotating drum

Question 17

controls of a spirometer

Answer 17

soda and lime used to absorb carbon dioxide to individual doesn’t re uptake it
nose plug can be used so all breathing is recorded