gas exchange

Question 1

what are the projections on a gill arch called?

Answer 1

gill filaments

Question 2

what are the projections on gill filaments called?

Answer 2

lamellae

Question 3

in what direction do blood and water flow across the lamellae ?

Answer 3

opposite directions

(counter-current flow)

Question 4

what does the counter current flow ensure?

Answer 4

a steep diffusion gradient is maintained so equilibrium is never reached and all the oxygen can be diffused out of the blood

Question 5

what is inspiration?

Answer 5

breathing in

Question 6

what is expiration?

Answer 6

breathing out

Question 7

what happens in inspiration?

Answer 7

external intercostal muscles and diaphragm contract , volume of thoracic cavity increase , lung pressure decreases , air flows in

Question 8

what happens in expiration?

Answer 8

external intercostal muscles and diaphragm relax , volume of thoracic cavity decreases , air pressure increases , air forced out

Question 9

what happens in forced expiration?

Answer 9

external intercostal muscles relax , internal intercostal muscles contract ,

Question 10

what are the air sacs in the lungs called?

Answer 10

alveoli

Question 11

how are the alveoli adapted?

Answer 11

wall is a single layer of thin flat cells to ensure a short diffusion pathway
walls of the alveoli contain elastin protein to help the alveoli return to their normal shape after inhaling and exhaling

Question 12

what is the movement of oxygen through the body?

Answer 12

moves down the trachea , bronchi and bronchioles and into the alveoli down a pressure gradient , diffuses into the blood where it can be transported around the body
lots of them so there is a very large surface area to increase the rate of oxygen diffusion and gas exchange

Question 13

what is tidal volume?

Answer 13

the volume of air in each breath

Question 14

what is ventilation rate?

Answer 14

the number of breaths per minute

Question 15

what is forced expiratory volume?

Answer 15

the maximum volume of air that can be breathed out in 1 secondw

Question 16

what is forced vital capacity?

Answer 16

the maximum volume of air it is possible to breathe forcefully out of the lungs after a really deep breath itn

Question 17

how do lung diseases affect gas exchange?

Answer 17

reduce the rate of gas exchange in the alveoli

Question 18

how does lung disease affect a person?

Answer 18

the rate of gas exchange is reduced , so less oxygen is able to diffuse into the bloodstream , therefore the body cells receive less oxygen so the rate of aerobic respiration is reduced so less energy is released and the person may feel tired and weak

Question 19

what are 4 things that need to be exchanged with the environment?

Answer 19

respiratory gases
nutrients
excretory products
heat

Question 20

what are spiracles and how do they work?

Answer 20

they are tiny pores on the body surface of the insect that open and close using a valve
they can allow water vapour to evaporate from them and tend to shut to avoid water loss